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< Back to Issue 4 Fool Me Once by Julia Lockerd 1 July 2023 Edited by Tanya Kovacevic and Elijah McEvoy Illustrated by Sonia Santosa I have rabies. I’m absolutely sure of it. I mean, I can't really tell, but that’s the silent killer, right? You don’t know you’re rabid till it’s all over, and you’re foaming at the mouth and biting your student tutor on the leg. Despite being completely safe here in Australia with its complete lack of rabies-having animals, I’m still pretty sure I’ve managed to catch it. Next week it will all be over for me and my tutor. Sorry, James. Of course, it’s not actually rabies that I’ve contracted, but a much more common condition: Medical Student Syndrome (1). Last week in my lectures, we learned all the ins, outs, and symptoms of the rabies virus. So, naturally, now we all have it. This health-related anxiety is a prime example of how our human brains can trick us into experiencing phantom symptoms. The same cognitive veil is used in clinical trials all over the world in order to test the efficacy of new drugs. We’ve all felt it. That moment when you question, ‘Is this real, or is my mind making its reality?’ We call this the placebo effect. The placebo effect is crucial to modern and historical experimental design. The ‘trickable’ nature of the human mind has changed the course of drug development as we know it. The effects’ success hinges on a patient's belief that they are receiving treatment for their ailment. The simple belief in a cure can often result in real physiological changes in an individual. This makes the placebo effect a very powerful tool in the development of new drugs for the market. In a placebo-controlled trial, half of the sample population will be blindly given a placebo, and the other half of the drug being tested. In order for a potential treatment to be considered effective, it must produce more significant results than the placebo group (2). We must improve our approach to designing and researching hypotheses. Can we use what we know about the placebo effect to make more accurate claims about modern pharmaceutical development? Well, in 2017, Dr. Sara Vanbheim of the Arctic University of Norway published a study that brought into consideration the possible effects of differing sexual characteristics on placebo efficacy (3). This idea could restructure the way experiments are designed going forward and potentially provoke a possible review of drugs already on the market. Is it possible that traditionally marginalised groups are underrepresented in the clinical trial process? Can we restructure experiments to be more inclusive? Are changes even really necessary? These questions were investigated through the compilation and calculation of placebo and nocebo effects on men and women over multiple previously conducted studies mostly centering around physical pain and the administration of analgesia. The term ‘nocebo’ defines the antithesis of a placebo (4), referring to adverse side effects a subject feels when given an inert version of the test drug. While placebos tend to have an analgesic effect, nocebos often cause negative effects or emotions when the subjects are told that they should expect/anticipate them. Before discussing any of these questions, it is worth noting that the Norwegian study focuses solely on classic sexual differences between cis-gender men and women. Though both keywords ‘gender’ and ‘sex’ were included in the study, research surrounding the specific effects of gender identity and gender-affirming therapies on placebos has not been thoroughly conducted as of 2023. It is with this focus that the following hypotheses are stated (3): “1) placebo responses would be stronger or more frequently observed in males than in females, 2) nocebo responses would be stronger or more frequently observed in females than in males, 3) verbally induced placebo responses would be more frequently observed in males than in females, and 4) conditioned nocebo responses would be more frequently observed in females than in males.” Results concluded that there was indeed a significant correlation between sex and placebo/nocebo effects when concerning pain relief. But what is truly fascinating is that while men received elevated levels of a placebo effect, such as reduced symptoms and analgesia, women were more susceptible to hyperalgesia and negative emotions. Those supposed ‘side effects’ appear to weigh more heavily on women (3). What does this say about how men and women process pain and information? The Norwegian study discusses the role of ‘psychophysiological mechanisms’ in pain pathways. Or, more simply, How stress and anxiety can affect the pain the brain perceives. In 8 of the 12 studies, men experienced significantly stronger analgesic effects from the placebo than women (3). It is plausible that men react more strongly to pain induced by stress hormones. This would explain why when taking a placebo, their anxiety level would decrease, and they would receive higher levels of analgesia than their female counterparts (3). Another study, upon which the Norwegian argument builds, investigates placebo delivery methods and their effect on perceived pain in men and women. In this study, men relied far more on verbal queues to provide analgesia, whereas women received a more significant effect from classic conditioning (5). These studies bring into question both the methodological and physiological effects of placebos on different sexes. What do these differences tell us about how men and women perceive the world? And what does this mean for the future of the placebo? The result of all of these studies is to show not whether placebos are bad or good, reliable or unreliable, but instead to highlight the differences in the physiological and psychological links when looking at different groups of people. At its core, a placebo is simply a trick of the brain, a psychological mirage. While the basis and reliability of placebos can be debated at length, their effect on the human brain teaches us something about ourselves societally. In all areas of medicine, the inclusion of people from all different backgrounds, genders, ethnicities, and ages is crucial so professionals know how to identify and treat various manifestations of a disease with grace and care. Now I know James responds better to verbal commands; I’ll be sure to tell him he has rabies the next time I see him. References Henning Schumann J. I contracted medical student syndrome. You probably will too. [Internet]. AAMC. [cited 2023 Jun 22]. Available from: https://www.aamc.org/news/i-contracted-medical-student-syndrome-you-probably-will-too Harvard Health Publishing. The power of the placebo effect - Harvard Health [Internet]. Harvard Health. Harvard Health; 2021. Available from: https://www.health.harvard.edu/mental-health/the-power-of-the-placebo-effect Vambheim S, Flaten MA. A systematic review of sex differences in the placebo and the nocebo effect. Journal of Pain Research. 2017 Jul;Volume 10:1831–9. National Cancer Institute NCI. Definition of nocebo effects [Internet]. www.cancer.gov . 2011. Available from: https://www.cancer.gov/publications/dictionaries/cancer-terms/def/nocebo-effect Enck P, Klosterhalfen S. Does Sex/Gender Play a Role in Placebo and Nocebo Effects? Conflicting Evidence From Clinical Trials and Experimental Studies. Frontiers in Neuroscience. 2019 Mar 4;13. 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< Back to Issue 8 The Lost Link: A Mystery in Evolution by Eymi Gladys Carcamo Rodriguez 3 June 2025 Edited by Ciara Dahl Illustrated by Anabelle Dewi Saraswati The Enigma of Evolutionary Gaps Few scientific mysteries have captured the public imagination as deeply as the search for the “missing link”, a hypothetical species that bridges the evolutionary gap between ancient primates and modern humans. For generations, scientists and the public alike imagined that a single fossil discovery would neatly connect our distant ancestors to Homo sapiens . Yet as our understanding of evolution has grown, it has become clear that the story is far more complex. Rather than a single missing puzzle piece, human evolution is now regarded as a tangled web of interconnected species, with many branches and dead ends (1). The Myth of the Missing Link Historical Context The term “missing link” surged in popularity during the 19th century, following Charles Darwin’s ground-breaking work on the theory of evolution. Early evolutionary theorists envisioned a linear process: one species evolving directly into another, with the “missing link” as the crucial fossil that would clearly show how humans evolved from apes. This view persisted in popular culture; even as scientific evidence began to suggest otherwise. In Victorian England, the idea of a missing link became a cultural phenomenon. Fossil discoveries–like the first Neanderthal skulls–were hailed as evidence of humanity’s ascent from apes. However, modern evolutionary biology has revealed that evolution is not linear, but a branching tree, filled with dead ends and interwoven paths (2). The Fossils: Pieces of a Complex Puzzle Despite a shift in scientific thinking, fossil discoveries remain central to our understanding of human origins. Iconic finds such as Australopithecus afarensis (“Lucy”), Homo habilis , and Homo naledi have each provided snapshots of different stages in human evolution. Yet, none of these fossils fit the mould of the elusive “missing link” (3, 4). Australopithecus afarensis (c. 3.9–2.9 million years ago) walked upright and had both human-like and ape-like features. Lucy’s skeleton suggests a close connection to the human lineage, but her brain size and cranial features remain distinctly primitive. Homo habilis , one of the earliest members of our genus, shows evidence of tool use and increased brain size, but still differs significantly from modern humans. These fossils demonstrate that human evolution was not a simple progression from one species to the next. Many early hominins coexisted for millions of years, and some, like Homo habilis , may have lived alongside more primitive ancestors such as Australopithecus . The idea of a singular “missing link” is now viewed as a historical artifact, replaced by the recognition that human evolution is a mosaic, with branches and offshoots that defy easy classification. The Persistent Gaps Despite advances in palaeontology and genetics, many questions about human evolution remain unanswered: Why did early human brains grow so rapidly? Around 2 million years ago, our ancestors experienced a dramatic increase in brain size. The causes-whether tool use, diet, or social complexity-are still debated. How much did early humans interbreed with other hominins? Ancient DNA reveals that Homo sapiens interbred with Neanderthals and Denisovans, raising questions about the scale and impact of these interactions. Why did Homo sapiens spread so quickly across the globe? Our species began migrating out of Africa roughly 60,000 years ago, adapting rapidly to new environments. The role of culture, technology, and innovation in this expansion is still being explored (5). These questions highlight the complexity and dynamism of human evolution, suggesting that the process was shaped by a mix of biological and environmental factors. DNA: The New Frontier in the Search for the Missing Link While fossils have provided crucial insights, the latest breakthroughs come from genetic research. Advances in DNA sequencing allow scientists to peer into the ancient past in unprecedented ways. One of the most surprising findings is the discovery of a “ghost population” – an ancient group whose DNA is present in modern humans, but whose fossils have never been found. These genetic traces suggest that entire populations once co-existed and interbred with Homo sapiens , yet left no physical evidence behind. This challenges the traditional fossil-focused search for the missing link and highlights the importance of genetic inheritance in understanding our origins (6). “The idea that entire populations could have existed and disappeared without leaving any fossil evidence challenges our traditional search for the missing link. It suggests that the story of human evolution is not just about the fossils we find, but also about the genetic material we carry with us today” (7). The Real Missing Link: A Paradigm Shift The quest for a single missing link is now seen as outdated. Evolution is not a straight line but a complex web, with species branching, merging, and sometimes vanishing without a trace. Rather than a specific fossil, the “missing link” has become a symbol of our evolving understanding of what it means to be human. Each new discovery-whether in the fossil record or in our DNA-forces us to rethink our place in nature and the forces that shaped our evolution. Conclusion: The Journey of Discovery Continues The story of human evolution remains incomplete. Each new fossil and genetic breakthrough bring us closer to understanding our origins, but the mystery endures. The search for the missing link may never be resolved, and perhaps it is not meant to be. Instead, it is the ongoing process of discovery that enriches our understanding of who we are and where we came from. References Veldhuis D, Kjærgaard PC, Maslin M. Human Evolution: Theory and Progress. In: Smith C, editor. Encyclopedia of Global Archaeology. Cham: Springer International Publishing; 2020. p. 5317-30. Kjaergaard PC. 'Hurrah for the missing link!': a history of apes, ancestors and a crucial piece of evidence. Notes Rec R Soc Lond. 2011;65(1):83-98. Martinón-Torres M, Garate D, Herries AIR, Petraglia MD. No scientific evidence that Homo naledi buried their dead and produced rock art. J Hum Evol. 2024;195:103464. Schrein CM. Lucy: A marvelous specimen. Nature Education Knowledge. 2015;6(2). Chagi S. The Mosaic of Human Evolution: Challenging the Concept of a Singular ‘Missing Link’ World of Paleoanthropology2024 [Available from: https://worldofpaleoanthropology.org/2024/08/27/the-mosaic-of-human-evolution-challenging-the-concept-of-a-singular-missing-link/ . Sample I. Scientists find evidence of 'ghost population' of ancient humans: The Guardian Australia; 2020 [Available from: https://www.theguardian.com/science/2020/feb/12/scientists-find-evidence-of-ghost-population-of-ancient-humans . Banich MT. The Missing Link: The Role of Interhemispheric Interaction in Attentional Processing. Brain and Cognition. 1998;36(2):128-57. Previous article Next article Enigma back to

Our Microbial Frenemies By Wei Han Chong How could it be that some of the smallest organisms known to mankind can hold so much influence and cause such calamity in our lives? The significance of these microorganisms have long eluded the greatest microbiologists. But has our perception of these microbes blinded us to their advantages, if any? Edited by Khoa Anh Tran & Tanya Kovacevic Issue 1: September 24, 2021 Illustration by Rachel Ko Throughout human history, diseases and plagues have amassed death tolls reaching hundreds of millions, if not billions. From the Black Death in the 14th century, which killed about 200 million people, or about 30–50% of Europe’s population, to outbreaks of tuberculosis and typhoid fever, resulting in 1.4 million and 200,000 deaths every year, respectively (1, 2, 3). It should come as no surprise then that we have long perceived these microorganisms as a threat to public health and have consequently sought to eradicate these microbes from our environment. But have we been looking at them the wrong way? First and foremost, we know very little about the microorganisms living around us. In bacterial species alone, some scientists have estimated around a billion species worldwide, though even this value is believed to be a gross underestimation (4). Before the germ theory, the most widely accepted theories were the spontaneous generation and miasma theories. Spontaneous generation was a simple theory, believing that living organisms could develop from nonliving matter, such as maggots developing from rotting flesh. The miasma theory, on the other hand, was more prevalent throughout both ancient and modern history. From this perspective, “toxic” vapours from rotting organisms or unsanitary locations were believed to have caused disease (5). This all changed with the germ theory of disease: an idea that would revolutionise our understanding of microorganisms for centuries to come. First theorised as “invisible seeds” by Italian scholar Girolamo Fracastoro in 1546, Fracastoro believed that these seeds could cause disease when spread from infected to healthy individuals (6). For the most part, the basis of the germ theory would continue to follow this logic of a specific microorganism, a “germ”, that could cause a specific disease when invading its host (7). Yet, it was not until nearly 200 years later that the field of microbiology would see huge developments. In 1861, French scientist Louis Pasteur had disproved the spontaneous generation theory by means of sterilisation and proper sealing of food items, which would prevent microbial growth (8). However, Louis Pasteur would not be the only one contributing to developments in microbiology. In 1884, German scientist Robert Koch would be the first to develop a classification system for establishing a causative relationship between a microorganism and its respective disease, effectively confirming the germ theory of disease (9). Even to this day, Koch’s system is still very much influential in microbial pathogenesis, albeit refined to a higher standard. Now known as Koch’s Molecular Postulates — as opposed to Koch’s Original Postulates — which is a model that places a greater emphasis on the virulence genes causing disease, rather than the microorganism itself (10). Today, while we have much to thank Pasteur and Koch for in laying the foundation of modern microbiology, undoubtedly one of the biggest discoveries in microbiology was the discovery of the human microbiota. When we think of microbial life, we usually think of diseases and plagues, cleanliness and dirtiness. Rarely do we ever consider the idea of microbes living inside and around us. Yet, even less so can we begin to comprehend the sheer number of microorganisms that live and proliferate all around ourselves. In our gastrointestinal tract, estimates suggest that there are some 100 trillion microorganisms encoding three million genes altogether, which is 130 times more than what we encode ourselves (11). Figure 1. Microbes in Food (25) So, what do we know about the microbiota; specifically, our microbiota? Firstly, we know that the microorganisms occupying our gut do not cause disease, under normal circumstances. Secondly, we know that they can provide us with a multitude of benefits, such as helping us digest complex organic molecules, and preventing invasion of foreign microbes by directly competing for resources and keeping the immune system stimulated. These are just a few of the advantages our microbial allies provide us. However, that is not to say that they pose no danger to ourselves either. Typically, these microorganisms are categorised into being in a beneficial, pathogenic or commensal relationship with its host. Beneficial microbes, or probiotics, are as the name suggests: these microbes typically provide some form of health benefit to the host and are usually non-pathogenic. Many of the bacterial species found in our gut lumen, for example, have the capability to digest cellulose. As such, without these microbes, digesting vegetables would be a much harder and less rewarding task. Most of the probiotics found in our microflora are of lactic acid bacteria origin and are most common in diets that incorporate fermented dairy products (12). Pathogenic microbes, on the other hand, mostly describe microbes of foreign origin. These microorganisms will infect and exploit the host’s cells, ultimately causing disease. Commensal microorganisms walk an interesting line, in comparison to beneficial and pathogenic microbes. This group of microbes encompasses all of the characteristics described above, depending on circumstance. This ranges from benefiting both the host and microbe, the microbe itself, or even causing disease within its host when given the opportunity. An example of a commensal microorganism is Escherichia coli, or E. coli. It is a bacterium that colonises our gastrointestinal tract as soon as we are born, where it fends off more than 500 competing bacteria species, thanks to its versatility and adaptations to our gut environment (13). Furthermore, the presence of E. coli along our gut epithelium helps to stimulate mucin production, inhibiting any foreign microbes from invading the epithelium (14). However, as is typical of a commensal organism, when given the chance, E. coli is capable of causing intestinal or extraintestinal disease in our bodies. Urinary tract infections due to E. coli are among the most common causes of a microflora-associated infection and often occur when the bacterium is allowed to enter the urinary tract via cross contamination with the anus, where E. coli is typically shed as part of the faeces (15). Typically, these beneficial and commensal bacteria are found all over our body. They can be found in our hair, on our skin, and as we have discussed, in our gut. Malassezia, for example, is a fungus that colonises our scalp, and is what causes dandruff in most people. While dandruff may be a nuisance to those who experience it, do the disadvantages necessarily outweigh the benefits? The presence of Malassezia on our scalps means that other, possibly dangerous, microorganisms will have to compete with Malassezia in order to invade. Additionally, the stimulation of our body’s defenses due to Malassezia aids in repelling foreign invaders (16). Staphylococcus aureus is another example of a commensal microbe, and an even better example of an opportunistic pathogen that can be found living harmoniously on our skin and nasal passages, helping us fend off other competing microbes just as Malassezia does on our scalp. However, when the skin is pierced, whether by means of injury or even medically through surgeries or treatments, the Staphylococcus bacteria will opportunistically attempt to invade and infect its host (17). As such, Staph infections and outbreaks are among some of the most common forms of hospital-related infections (18). Source: Thomas L Dawson, “What causes dandruff, and how do you get rid of it?” February 10, 2021, Ted-Ed video (19). Looking to the future, we have begun to see a spike in non-communicable diseases as opposed to microorganism-based diseases. These include most forms of heart diseases, cancers, diabetes, and others. Still, while the rise of non-communicable diseases is arguably a cause for concern, the return of long extinct diseases and antibiotic resistant pathogens may prove costly. Staph infections, as previously mentioned, are extremely common in hospital environments where continued usage of antibiotics such as penicillin or methicillin has produced a “super strain” of Staphylococcus that is resistant to most commercially available drugs (20). Currently, superbugs such as multidrug-resistant mycobacterium tuberculosis and methicillin-resistant Staphylococcus aureus are most common in healthcare settings, but community transmissions have become a concern (21). As such, with our current practices of antibiotic overprescriptions and continued reliance on sterilisation, future outbreaks of mutated and resistant pathogens may be inevitable. That being said, should we redefine what “clean and sterile” means to us? Should “sterile” necessarily be a microbe-free environment? Our perception of microbial life has consistently been “antibacterial” and believed to have been a threat to public health ever since the inception of the germ theory. However, the fact of the matter is that these microorganisms are unavoidable. There are microorganisms living all over us. Our fingers, our phones, even the soles on our shoes carry certain microorganisms. In hospital rooms, the composition of microbes is constantly changing as patients and visitors enter and leave (22). Besides, the composition of microbes in the environment is not determined solely by its occupants. Other factors, such as ventilation and even architecture, can determine what microbes we find in our environment. In fact, hospital rooms with more airflow and humidity were found to have suppressed the growth of potential pathogens and had fewer human-associated bacteria in its microbial composition (23). Just as the microbe composition in the environment can be determined by architectural and building factors, the microbe composition in our microflora can hold incredible influence over our physiology. Dysbiosis, an imbalance in our microflora, can occur as a result of repeated consumption of antibiotics, and it is a serious illness resulting in a significant loss of beneficial and commensal microbes (24). Consequently, invasion and colonisation capabilities of foreign pathogens is increased; as has been shown in antibiotic-treated mice exposed to M. tuberculosis, where pathogenic colonisation was promoted when in a dysbiotic state (25). Other factors, such as diet and lifestyle, also contribute as “disturbance” factors that influence dysbiosis, as can be seen in typical Western-style diets that mostly consist of high fatty and sugary foods (26). In the future, while the crises of pandemics originating from drug-resistant superbugs loom over us, our understanding of microbial life has come far; from its humble beginnings as a rejected theory amongst scholars, to the discovery of an extensive microbial ecosystem inside of our guts. Despite that, our comprehension of this “hidden world” remains lacking, and we have yet to fully realise the potential of microbial life. Throughout history we have constantly taken an antimicrobial stance to preserve public health, but in recent times it has become increasingly clear that these microorganisms play a much greater role in health. References: 1. LePan, Nicholas. “Visualizing the History of Pandemics.” Visual Capitalist. Last modified September 2021. https://www.visualcapitalist.com/history-of-pandemics-deadliest/ . 2. World Health Organization. “Tuberculosis.” Published October 2020. https://www.who.int/news-room/fact-sheets/detail/tuberculosis . 3. Centers for Disease Control and Prevention. “Typhoid Fever and Paratyphoid Fever.” Last modified March 2021. https://www.cdc.gov/typhoid-fever/health-professional.html . 4. Dykhuizen, Daniel. “Species Numbers in Bacteria.” Supplement, Proceedings. California Academy of Science 56, no. S6 (2005): 62-71. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3160642/ . 5. Kannadan, Ajesh. “History of the Miasma Theory of Disease.” ESSAI 16, no. 1 (2018): 41-43. https://dc.cod.edu/essai/vol16/iss1/18/ . 6, 8. Greenwood, Michael. “History of Microbiology – Germ Theory and Immunity.” News-Medical. Last modified May 2020. https://www.news-medical.net/life-sciences/History-of-Microbiology-e28093-Germ-Theory-and-Immunity.aspx . 7. Britannica. “Germ theory.” Last modified April 2020. https://www.britannica.com/science/germ-theory . 9, 10. Gradmann, Christoph. “A spirit of scientific rigour: Koch’s postulates in twentieth-century medicine.” Microbes and Infection 16, no. 11 (2014): 885-892. https://doi.org/10.1016/j.micinf.2014.08.012 . 11. Valdes, Ana M, Jens Walter, Eran Segal, and Tim D Spector. “Role of the gut microbiota in nutrition and health.” BMJ 361, no. k2179 (2018): 36-44. https://doi.org/10.1136/bmj.k2179 . 12, 24. Martín, Rebeca, Sylvie Miquel, Jonathan Ulmer, Noura Kechaou, Philippe Langella, and Luis G Bermúdez-Humarán. “Role of commensal and probiotic bacteria in human health: a focus on inflammatory bowel disease.” Microbial Cell Factories 12, no. 71 (2013): 1-11. https://doi.org/10.1186/1475-2859-12-71 . 13, 15. Leimbach, Andreas, Jörg Hacker, and Ulrich Dobrindt. “E. coli as an All-rounder: The Thin Line Between Commensalism and Pathogenicity.” In Between Pathogenicity and Commensalism, edited by Ulrich Dobrindt, Jörg Hacker and Catharina Svanborg, 3-32. Springer: Berlin, 2013. 14. Libertucci, Josie, and Vincent B Young. “The role of the microbiota in infectious diseases.” Nat Microbial 4, no. 1 (2019): 35-45. https://doi.org/10.1038/s41564-018-0278-4 . 15. Harvard Medical School. “When urinary tract infections keep coming back.” Published September 2019. https://www.health.harvard.edu/bladder-and-bowel/when-urinary-tract-infections-keep-coming-back . 16. Saunders, Charles W, Annika Scheynius, Joseph Heitman. “Malassezia Fungi Are Specialized to Live on Skin and Associated with Dandruff, Eczema and Other Skin Diseases.” PLoS pathogens 8, no. 6 (2012): 1-4. https://doi.org/10.1371/journal.ppat.1002701 . 17. Cogen, A. L., V. Nizet, and R. L. Gallo. “Skin microbiota: a source of disease or defence?” British journal of dermatology 158, no. 3 (2008), https://doi.org/10.1111/j.1365-2133.2008.08437.x . 18, 20. Klein, Eili, David L Smith, and Ramanan Laxminarayan. “Hospitalizations and Deaths Caused by Methicillin-Resistant Staphylococcus aureus, United States, 1999–2005.” Emerging infectious diseases 13, no. 12 (2007): 1840-1846. https://doi.org/10.3201/eid1312.070629 . 19. Dawson, Thomas L. “What causes dandruff, and how do you get rid of it?” February 10, 2021. Ted-Ed video, 5:04. https://youtu.be/x6DUOokXZAo . 21. Better Health. “Antibiotic resistant bacteria.” Last modified March 2017. https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/antibiotic-resistant-bacteria#bhc-content . 22, 23. Arnold, Carrie. “Rethinking Sterile: The Hospital Microbiome.” Environmental health perspective 122, no. 7 (2014): A182-A187. https://doi.org/10.1289/ehp.122-A182 . 25. Khan, Rabia, Fernanda C Petersen, and Sudhanshu Shekhar. “Commensal Bacteria: An Emerging Player in Defense Against Respiratory Pathogens.” Frontiers in Immunology 10, no. 1 (2019): 1203-1211. https://doi.org/10.3389/fimmu.2019.01203 . 26. Schippa, Serena, and Maria P Conte. “Dysbiotic Events in Gut Microbiota: Impact on Human Health.” Nutrients 6, no. 12 (2014): 5786-5805. https://doi.org/10.3390/nu6125786 . 27. Sottek, Frank. Microbes in Food. c. 1904. The Tacoma Times, Tacoma. https://commons.wikimedia.org/wiki/File:Sottek_cartoon_about_microbes_in_food.jpg .

< Back to Issue 8 Friend or Foe?: The Mechanisms Behind Facial Recognition by Mishen De Silva 3 June 2025 Edited by Luci Ackland Illustrated by Aisyah Mohammad Sulhanuddin Among the many mysteries which encompass the world around us, lies a complex interaction right under our nose, or perhaps… right above it. In the labyrinth of human consciousness, we rely on the seemingly arbitrary judgements made from the combination of two eyes, a nose, and a mouth, to discern who might be a friend or foe. Facial recognition gives a snapshot into the intricate dance between our perception and cognition, which allows us to cultivate a more detailed understanding of those around us, and their thoughts, feelings and emotions. In those fleeting moments when you recognise your parents in a sea of unfamiliar faces, spot your friends ensconced among the rows of the lecture theatre, or simply bump into an old friend in a crowd of unacquainted strangers, your brain is able to identify faces in a fraction of a second, a remarkable feat of the human cognitive capacity. But what enables us to distinguish one face from another? How do the faces of those we know stand out from the countless other noses, eyes and mouths we see? To understand what makes these interactions so meaningful, we need to take a closer look at the mechanisms behind facial recognition and decoding within the brain. The Brain’s Blueprint To be human is to seek meaning, even when none may exist. The mind has transformed what is two eyes above a nose, and a nose above a mouth, into its own pattern for classifying the identities and expressions we see around us. Many studies have suggested facial processing to be holistic, where the featural patterns of the eyes, nose and mouth are perceived together and upright (1,2). This mechanism of holistic facial processing explains the interesting phenomena behind pareidolia, where the brain adapts the characteristics of human faces onto everyday objects. It’s the reason why when glancing at a bowling ball it may appear surprised (3), or why some have sworn to see a face on Mars (4)! Figure 1. Bowling balls with surprised facial expressions! (3) In pursuit of meaning for the patterns around us, the brain has developed specialised regions for processing the features of a face to help us recognise individual identities. Facial processing operates through a hierarchical mechanism where distinct aspects of the face are interpreted by different regions of the brain. The unchanging elements of the face such as gender, age, ethnicity and features related to someone’s identity are analysed by the Inferior Occipital Gyrus and Fusiform Face Area (FFA), while the changing aspects such as eye gaze, lip movements and facial expressions are analysed by the Superior Temporal Sulcus and Orbitofrontal Cortex (5,6). Of these face-selective regions, the FFA is particularly important for facial recognition as it helps us recognise who a person is (5). Through the activation of our FFA simple patterns shift from meaningless shapes into familiar visages representing our friends, family, or even our own reflection. Studies have uncovered the importance of the FFA for facial recognition by examining what may happen when this brain region malfunctions (7,8). A unique example of this is prosopagnosia, which results from damage to the FFA in the right hemisphere of the brain (9). Prosopagnosia is a relatively rare condition affecting about 1 in 50 people, impairing their ability to recognise faces (9). Imagine if every face you observed looked the same or unfamiliar… even your own reflection! It is through the brain and its specialised regions for facial recognition where we can appreciate the essence of human connection as a result of our neural hardware. These mechanisms responsible for transforming patterns into faces are the reason we can recognise our neighbour from a stranger, friend from a classmate, or our parents from a teacher. Often overlooked amidst the fleeting and impermanent nature of our social interactions, this complex system guides us along the fragile line of human relationships, between familiarity and estrangement, a friend or foe. It highlights how deeply-rooted our connection and sense of identity is to the faces we see. The Brain’s Threat Detection With each neuron, synapse and pathway, our brains are machines wired for connection, not just in how we think, but also in how we perceive and interact with our surroundings. From the brief exchange of smiles with a stranger, to the furtive glare from someone across the room, one of the hallmarks of our emotional understanding is the ability to decode the thoughts and intentions of others, even from the most subtle of expressions. In the vast and intricate web of neural connectivity, it can be difficult to isolate a singular brain region or connection to explain complex cognitive functions. Brain imaging studies have found a strong bidirectional link between the FFA and amygdala, making this a likely candidate for explaining our remarkable decoding ability (10,11). As the FFA picks up on who a person is or what facial expression is being made, it is the amygdala which then evaluates the emotional salience, or importance, of this face. The amygdala then signals back to the FFA to either increase or decrease the facial processing activity accordingly (10,12). Consider how the visibility of teeth in a barred expression can signal anger, the whiteness of someone’s eyes can hint fear or surprise, and the shape of a person’s eyebrows can indicate the intensity of their emotion, all which guide the brain to prioritise and interpret socially and emotionally relevant cues – almost like a survival filter! (13,14,15). From an evolutionary perspective, the FFA-amygdala feedback loop serves as an important tool for rapidly and accurately interpreting the intentions of others, a pinnacle function in the architecture of our physical and social survival (16). The ability to recognise whether someone poses a friend or foe has been a survival mechanism and evolutionary advantage for millennia. The role of our facial processing network, from the amygdala and FFA, to other brain regions discussed, provides a microcosm into our nature as social beings, and our evolutionary selective changes, which have enhanced our ability to sense, respond to, and connect with those around us (17). In this way, maybe the most profound mysteries lie not in distant galaxies or ancient ruins, but are hidden in plain sight, within the faces we walk past every day. Our brain’s ability to read them is not merely a mechanism for decoding emotion, but a mirror into the nature of what it means to be human, where connection, trust, and survival have long been written in the expressions of those around us. References 1. Farah M, Wilson K, Drain M, Tanaka J. What is “special” about face perception?. Psychological Review [Internet]. 1998 Aug [cited 2025 May 14]; 105(3):482–98. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC5561817/ 2. Richler J, Gauthier I. A meta-analysis and review of holistic face processing. Psychological Bulletin [Internet]. 2014 Sep [cited 2025 May 14]; 140(5): 1281–302. Available from: https://pubmed.ncbi.nlm.nih.gov/24956123/ 3. What do you think these bowling balls saw to leave them so surprised & shocked?. Reddit [Internet]. 2022 [cited 2025 May 31]. Available from: https://www.reddit.com/r/Pareidolia/comments/zc12jo/what_do_you_think_these_bowling_balls_saw_to/#lightbox 4. Gilbert L. Why the brain is programmed to see faces in everyday objects. UNSW Sites [Internet]. 2020 Aug [cited 2025 May 14]. Available from: https://www.unsw.edu.au/newsroom/news/2020/08/why-brain-programmed-see-faces-everyday-objects 5. Kanwisher N, Yovel G. The fusiform face area: a cortical region specialized for the perception of faces. Philosophical Transactions of the Royal Society: Biological Sciences [Internet]. 2006 Dec 29 [cited 2025 May 14]; 361(1476):2109–28. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1857737/ 6. Zhen Z, Fang H, Liu J. The Hierarchical Brain Network for Face Recognition. Ptito M, editor. PLoS ONE [Internet]. 2013 Mar [cited 2025 May 14]; 8(3):e59886. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0059886 7. Hadjikhani N, de Gelder B. Neural basis of prosopagnosia: An fMRI study. Human Brain Mapping [Internet]. 2002 [cited 2025 May 14]; 16(3):176–82. Available from: https://onlinelibrary.wiley.com/doi/abs/10.1002/hbm.10043 8. Sorger B, Goebel R, Schiltz C, Rossion B. Understanding the functional neuroanatomy of acquired prosopagnosia. NeuroImage [Internet]. 2007 Apr [cited 2025 May 14] ;35(2):836–52. Available from: https://www.sciencedirect.com/science/article/pii/S1053811906009906 9. Prosopagnosia | Psychology Today Australia [Internet]. www.psychologytoday.com . [cited 2025 May 14]. Available from: https://www.psychologytoday.com/au/basics/prosopagnosia 10. Herrington J, Taylor J, Grupe D, Curby K, Schultz R. Bidirectional communication between amygdala and fusiform gyrus during facial recognition. NeuroImage [Internet]. 2011 Jun [cited 2025 May 14]; 56(4):2348–55. Available from: https://pubmed.ncbi.nlm.nih.gov/21497657/ 11. Said C, Dotsch R, Todorov A. The amygdala and FFA track both social and non-social face dimensions. Neuropsychologia [Internet]. 2010 Oct [cited 2025 May 14]; 48(12): 3596–605. Available from: https://pubmed.ncbi.nlm.nih.gov/20727365/ 12. Šimić G, Tkalčić M, Vukić V, Mulc D, Španić E, Šagud M, et al. Understanding Emotions: Origins and Roles of the Amygdala. Biomolecules [Internet]. 2021 May [cited 2025 May 14]; 11(6):823. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC8228195/ 13. Jacobs R, Renken R, Aleman A, Cornelissen F. The amygdala, top-down effects, and selective attention to features. Neuroscience & Biobehavioral Reviews [Internet]. 2012 Oct [cited 2025 May 14]; 36(9):2069–84. Available from: https://pubmed.ncbi.nlm.nih.gov/22728112/ 14. Horstmann G, Lipp O, Becker S. Of toothy grins and angry snarls – Open mouth displays contribute to efficiency gains in search for emotional faces. Journal of Vision [Internet]. 2012 May [cited 2025 May 14]; 12(5):7–7. Available from: https://jov.arvojournals.org/article.aspx?articleid=2192034#:~:text=We%20suspected%20that%20visible%20teeth,(see%20also%20Figure%205).&text=Mean%20target%20present%20slopes%20(in,while%20angry%20faces%20do%20not.&text=Mean%20target%20present%20slopes%20(in,while%20angry%20faces%20do%20not . 15. Hasegawa H, Unuma H. Facial Features in Perceived Intensity of Schematic Facial Expressions. Perceptual and Motor Skills [Internet]. 2010 Feb [cited 2025 May 14]; 110(1):129–49. Available from: https://pubmed.ncbi.nlm.nih.gov/20391879/ 16. Schmidt K, Cohn J. Human facial expressions as adaptations: Evolutionary questions in facial expression research. American Journal of Physical Anthropology [Internet]. 2001 [cited 2025 May 14]; 116(S33):3–24. Available from: https://pubmed.ncbi.nlm.nih.gov/11786989/ 17. Carter E, Pelphrey K. Friend or foe? Brain systems involved in the perception of dynamic signals of menacing and friendly social approaches. Social Neuroscience [Internet]. 2008 Jun [cited 2025 May 14]; 3(2):151–63. Available from: https://pubmed.ncbi.nlm.nih.gov/18633856/ Previous article Next article Enigma back to

< Back to Issue 6 A Frozen Odyssey: Shackleton’s Trans-Antarctic Expedition by Ethan Bisogni 28 May 2024 Edited by Rita Fortune Illustrated by Aisyah Mohammad Sulhanuddin The Heroic Age of Antarctic Exploration South of the 66th parallel lies a continent desolate and cruel, where the experiences of those who dared to challenge it are preserved in its ice. Antarctica was deemed Earth’s final frontier by 19th-century explorers, and at the cusp of the 20th century, the ‘Heroic Age of Antarctic Exploration’ was underway (Royal Museums Greenwich, n.d. a). Those who answered the call of the wild, to face the polar elements, would be remembered as heroes. Among the pantheon of Antarctic explorers, none are more celebrated than Sir Ernest Shackleton. An Irishman whose name became synonymous with adventure and peril, Shackleton emerged at the forefront of Britain’s polar conquests. During his Nimrod expedition to reach the magnetic South Pole, Shackleton and his crew found themselves within 100 miles of their goal—only to be thwarted by their human needs (Royal Museums Greenwich, n.d. b). His ambition outmatched the capabilities of those he commanded, so they withdrew for want of survival. Despite the supposed failure of the two-year expedition, Shackleton’s romanticism of exploration, leadership, and unwavering optimism earned him a knighthood in 1909 (Royal Museums Greenwich, n.d. b). In the years following, as other explorers performed increasingly remarkable polar feats, Shackleton was left in limbo. It was during this time that an impossibly ambitious expedition was put forward to him. The plan was as follows: a crew would sail a wooden barquentine, the Endurance, into the Weddell Sea, and land on the Antarctic coast. There, the men would split into groups, and Shackleton would pursue a daring transcontinental journey across Antarctica (Smith, 2021). Despite the questionable feasibility of this plan, a benefactor named James Caird sought to help fund the expedition (Smith, 2021). Thus, these plans were translated into reality, and with a finalised crew of 27, the Endurance was set to sail under the helm of New Zealand captain Frank Worsley. On August 1st, 1914, the Endurance departed Plymouth (PBS, 2002). Explorers of the Antarctic, from left: Ronald Amundsen, Sir Ernest Shackleton, Robert Peary (Antarctica 21, 2017) The Imperial Trans-Antarctic Expedition Into the Weddell Sea, December 5th, 1914 After their momentary recess in South Georgia, and the recent pickup of a stowaway, the Grytviken whaling station remained the crew's last semblance of civilisation (PBS, 2002). Shackleton was well aware of the challenges that loomed ahead—notorious for its hostility, the Weddell Sea was Antarctica’s first line of defence (Shackleton, 1919). In the coming days, the Endurance encountered pack ice, severely slowing its progress. A nightmarish phenomenon for any explorer, pack ice was an abundant drift of sea ice no longer connected to land. While plentiful, navigating it was not impossible—it only required patience, caution, and an intuitive hint of wisdom. But even with worsening conditions, Shackleton proceeded into unclear waters (Shackleton, 1919). The Endurance in the Weddell Sea (Hurley, 1914) Icebound, January 18th, 1915 The Endurance was again ensnared in ice, and this time the ship would not budge. Plagued by regret in pushing ahead, but desperate to break free, Shackleton ordered his men to cease routine. Once again, his ambition outpaced his capabilities, but Shackleton was also a man of determination. They would wait until an opening cleared (Shackleton, 1919). The ship began to drift northward with the ice, but as months passed, so too did any hope of landing. Time was running out, and with winter approaching, the Endurance would soon be engulfed by the long polar night (PBS, 2002). For this expedition to succeed, the crew needed to remain optimistic. A brotherhood formed on the ice, with theatre plays and celebrations to ease their dire worries. The eerie creak of the hull did not deter them from trekking the very ice that imprisoned them. The ship’s Australian photographer, Frank Hurley, captured these moments of perseverance on photographic plates, including the hauntingly beautiful Endurance beset amongst the snow (Shackleton, 1919). The Endurance in the night (Hurley, 1915) Abandon Ship, October 27th, 1915 True to its name, the Endurance weathered the dark winter months. But despite the comfort of a newly rising sun, disaster did not fade with the darkness. A catastrophic ice shift had violently imploded the ship’s hull, and with its fate sealed, the Endurance would not hold. Shackleton gave the order to abandon ship (Shackleton, 1919). Any hope of the expedition continuing was now lost alongside the Endurance , which was silently withering on the ice. Though this was not Shackleton’s first time in Antarctica, nor was it his first disastrous expedition. Stations of emergency supplies established by himself and other explorers were scattered across the islands of the Weddell Sea, each offering glimmers of hope. However, at over 500 kilometres away, they all required a potentially fatal journey (Shackleton, 1919). Frank Wild overlooking the wreck of the Endurance (Hurley, 1915) Ocean Camp, November 1st, 1915 A plan was conjured—they would march across the unforgiving ice, bringing themselves to one of the few sanctuaries along the Antarctic Peninsula. Concerns of risk from Captain Worsley fell on deaf ears; undeterred, Shackleton knew waiting was futile (Worsley, 1931). Leading up, a difficult decision was made to conserve the crew’s rations. Mrs. Chippy, the beloved ship cat of carpenter Harry McNish, was to be killed amongst the other animals (Canterbury Museum, 2018). Although believing it necessary, Shackleton’s remorseful orders to cull the animals aboard had cast a shadow over his leadership (Scott Polar Research Institute, n.d.). The march soon commenced, but horrendous conditions had led the men into a frozen labyrinth. After a pace of only a kilometre a day, the march was abandoned. The crew instead erected ‘Ocean Camp’, and were to wait for the ice to clear a path for their lifeboats (PBS, 2002). Weeks in, the crew's evening was interrupted by the ghostly wailing of the Endurance wreck . Beckoning in the distance, the men gathered to watch its final breaths. On November 21st, the ice finally caved in, and the Endurance was swallowed into the forsaken depths of the Weddell Sea (Worsley, 1931). Ocean Camp (Hurley, 1915) The Rebellion on the Ice, December 27th, 1915 With the crew’s last tether to the world severed, a depression had settled over the camp. Now dragging their lifeboats to open water, a quiet but persistent discontent was beginning to grow. Most of the crew still admired Shackleton as their resolute leader, but some were beginning to lose faith. A frustrated and grieving McNish made his stand, arguing that the loss of the Endurance had nullified Shackleton's command. Shackleton, furious but sympathetic, was able to successfully de-escalate the situation (Scott Polar Research Institute, n.d.). The mutiny was short-lived, but McNish was now under Shackleton's watchful eye. He knew that he would have to inspire hope, and that a rift in the crew would only prompt death. Dragging the lifeboats (Hurley, 1915) Elephant Island, April 14th, 1916 With three lifeboats in possession, a proposal to island-hop was presented. McNish had spent his time reinforcing the boats for open waters, and after careful deliberation, a destination was chosen. Elephant Island was a barren, windswept landscape—a false sanctuary harbouring an inhospitable environment. Landing there was not Shackleton’s first choice, but a fast approaching winter left no alternative (Shackleton, 1919). With Elephant Island looming over the horizon, the boats set forth. Battling the arduous sea, one of the lifeboats, the Dudley Docker , was torn away from the rest during an unprecedented storm. Fading into the vast darkness, the men aboard were presumed dead. No amount of enthusiasm from Shackleton could lift the crew's spirits, who were now delirious and grief stricken (Fiennes, 2022). The following day, a landing was imminent. Nearing the shore, a boat was noticed soaring in the distance. The Dudley Docker pierced through the waves—the crew still alive and following in hot pursuit. Ecstatic and revived with hope, landfall was made. A major milestone had been reached; the crew were now unified and ashore for the first time since South Georgia (Fiennes, 2022). Unfortunately, Elephant Island’s taunting winds carried no whispers of hope. The silence was apparent: this island would be their grave unless contact was made with civilisation. A party must be formed, one that would take the risk and sail into the heavy seas of the Southern Ocean (Shackleton, 1919). The shores of Elephant Island (Hurley, 1916) The Voyage of the James Caird, April 24th, 1916 Shackleton selected a route to a South Georgia whaling station neighbouring the one they had departed in 1914—a harrowing 1500 kilometres across notoriously restless seas. In one of their modified lifeboats, they were to utilise the prevailing westerlies to attempt an impossible sailing feat (Pierson, n.d.). Six men were selected to commander the James Caird : Shackleton, Worsley, McNish, Crean, Vincent, and McCarthy. As the James Caird set sail, a vast ocean of uncertainty lay between Elephant Island and South Georgia (Pierson, n.d.). The voyage was tortuous, with the men severely ill-prepared. From storm-fed waves to frigid winds, the James Caird and those aboard were unlikely to survive the journey. At each turn, however, the determined men managed to stay afloat and push ahead. 17 days passed before the dominant mountains of South Georgia came into view (PBS, 2002). Shackleton, fearing his men would not survive another day at sea, hastened a plan to land on the rocky western shores (Pierson, n.d.). The six men found themselves on the wrong end of the island to the station, and James Caird was in no state to navigate the coast. The capable individuals would have to perform the first trans-island crossing of South Georgia—a far cry from their original ambitions, but daring nonetheless. With only Shackleton, Worsley, and Crean able to attempt the task ahead, McNish, Vincent, and McCarthy were left to establish ‘Peggotty Camp’ in the landing cove (Pierson, n.d.). Waving goodbye to the James Caird (Hurley, 1916) The Crossing of South Georgia, May 10th, 1916 The three men began their journey northward towards the Stromness whaling station. Encountering menacing snow-capped peaks, the men were so close to potential rescue only to be divided by insurmountable odds. Needing to race the approaching night down a 3000-foot mountainside, a makeshift sled was constructed from their little equipment. Rocketing downhill, a rare moment of joy and exhilaration accompanied the men along their daredevilish tactics (Antarctica Heritage Trust, 2015). Exhausted and verging on collapse, the men were now nearing the outskirts of their destination. A whistle in the air had lured them closer, and on May 20th, 1916, contact was finally made. The men were tended to by the distraught station managers, and a rescue party was sent the following day to those abandoned at ‘Peggotty Camp’ (Pierson, n.d.). After multiple attempts to obtain a suitable vessel, the 22 remaining souls holding steadfast on Elephant Island were finally rescued by the Yelcho on August 30th, 1916. Hope was not lost amongst them, as even in his absence their belief in Shackleton kept their spirits alive. Bringing their ordeal to a close, and without a man’s life lost, the crew’s troubles were left behind in the frozen Antarctic (Shackleton, 1919). The Yelcho arrives to rescue the crew (Hurley, 1916) Legacy Published in 1919, ‘South’, Shackleton’s autobiographical recount of the expedition, brought these remarkable stories into the limelight. However, records stricken from the novel hide some concerning truths. While omitting the incident regarding McNish’s mutiny, it was clear Shackleton resented him for introducing doubt during their time of turmoil. Despite his redemption during their voyage to South Georgia, Shackleton recommended McNish not be awarded the Polar medal—a decision still considered mistakenly harsh (Scott Polar Research Institute, n.d.). But despite his flaws and misjudgments, Shackleton was undoubtedly the optimistic and courageous leader you would seek in times of crisis. In 1922, aboard his final expedition to circumnavigate Antarctica, Shackleton suffered a fatal heart attack - and was buried in South Georgia. Regarded as a defining moment, his death signalled the end of the ‘Heroic Age of Antarctic Exploration’ (Royal Museums Greenwich., n.d. b). Exactly one century following, the Endurance was found preserved at the bottom of the Weddell Sea. Its mast still bearing its inscription, the ship remains an enduring remnant of a heroic past. This inspiring tale of survival continues to live on, as one of the greatest stories of human perseverance in the face of the elements. The crew of the Endurance (Hurley, 1915) References Antarctica 21. (2017). Famous Antarctic Explorers: Sir Ernest Henry Shackleton. Antarctica 21 . https://www.antarctica21.com/journal/famous-antarctic-explorers-sir-ernest-henry-shackleton/ Antarctica Heritage Trust (2015). Crossing South Georgia. Antarctic Heritage Trust. https://nzaht.org/encourage/inspiring-explorers/crossing-south-georgia/ Canterbury Museum (2018), Dogs in Antarctica: Tales from the Pack. Canterbury Museum https://antarcticdogs.canterburymuseum.com/themes/hardships Fiennes, R (2022). Remembering a Little-Known Chapter in the Famed Endurance Expedition to Antarctica. Atlas Obscura, https://www.atlasobscura.com/articles/shackleton-endurance-elephant-island Hurley, F. (1914-1916). Imperial Trans-Antarctic Expedition Photographic Plates. [Photographs]. National Library of Australia. https://www.nla.gov.au/collections/what-we-collect/pictures/explore-pictures-collection-through-articles-and-essays/frank PBS (2002). Shackleton’s Voyage of Endurance. PBS Nova. https://www.pbs.org/wgbh/nova/shackleton/1914/timeline.html Pierson, G (n.d.), Excerpt: The Voyage of the James Caird by Enerest Shackleton. American Museum of Natural History. https://www.amnh.org/learn-teach/curriculum-collections/antarctica/exploration/the-voyage-of-the-james-caird Royal Museums Greenwich. (n.d. a). History of Antarctic explorers. Royal Museums Greenwich. https://www.rmg.co.uk/stories/topics/history-antarctic-explorers Royal Museums Greenwich. (n.d. b). Sir Ernest Shackleton. Royal Museums Greenwich. https://www.rmg.co.uk/stories/topics/sir-ernest-shackleton Scott Polar Research Institute (n.d.). McNish, Carpenter. University of Cambridge, Scott Polar Research Institute. https://www.spri.cam.ac.uk/museum/shackleton/biographies/McNish,_Henry/ Shackelton, E (1919). South: The Endurance Expedition. Heinemann Publishing House Smith, M (2021). Shackleton's Imperial Trans-Antarctic Expedition. Shackleton. https://shackleton.com/en-au/blogs/articles/shackleton-imperial-trans-antarctic-expedition Worsley, F (1931). Endurance: An Epic of Polar Adventure. W. W. Norton & Co Previous article Next article Elemental back to

< Back to Issue 6 Proprioception: Our Invisible Sixth Sense by Ingrid Sefton 28 May 2024 Edited by Subham Priya Illustrated by Jessica Walton What might constitute a sixth sense? Perhaps, it involves possessing a second sight or superhuman abilities. A classic example of this would be Spider-Man and his ‘spidey-sense’ — an instinctual warning system that alerts him to imminent danger. Enhancing his reflexes and agility, his sixth sense enables him to evade threats with precision. Turns out Spider-Man is not the sole bearer of a ‘spidey sense’. While we may not be scaling walls anytime soon, we too possess a special sense that unconsciously guides our movements. It might sound peculiar, but knowing your arm is indeed your own arm involves a unique form of sensory processing. Considered by neuroscientists as our own ‘sixth sense’, proprioception is our own way of helping the brain to understand the position of our body and limbs in space (Sherrington, 1907). Consider a typical scenario: your first sip of coffee in the morning. Eyes shut, you savour your latte before the day begins. Such a simple act, yet impossible without proprioception. With closed eyes, how do you know where your mouth is? How do you gauge the position of your arm to ensure the coffee cup reaches your lips? Proprioception seamlessly transmits information about muscle tension, joint position, and force to the brain, making drinking your coffee an automatic and coordinated process. Proprioception operates on principles akin to those guiding our other senses. Specialised cells, known as receptors, are found in each sensory organ and receive information from the environment. Receptors in your eyes capture visual information, while those in your ears detect auditory stimuli. This sensory information is transduced through signals to the central nervous system – through the spinal cord and to the brain – where it’s integrated and processed to determine an appropriate response. Analogously, proprioceptive information is mediated by proprioceptors, a unique type of receptors located in your muscles and joints (Proske & Gandevia, 2012). Unlike our other senses, proprioception does not rely on input from the external environment. Rather, it provides feedback to the brain about what the body itself is doing. Changes in muscle tension and the position of our joints are relayed to the brain, ensuring awareness of the body’s whereabouts at any given moment. One implication of this ‘internal’ feedback loop is that proprioception never turns ‘off’. When you cover your ears, you experience silence. If you hold your nose, you can block out the smell. Yet even when still, in motion, or unconscious, your brain continuously receives proprioceptive input. Imagine this in the context of going to bed each night. What exactly prevents you from falling out of bed, once asleep? While most senses are subdued when sleeping, proprioception remains active, informing the brain about the slightest changes in the position of the body. This ensures a perpetual awareness of our body in space – and luckily for us, stops us from rolling out of bed (Proske & Gandevia, 2012). It can be hard to appreciate what our proprioceptive system allows us to do, given its unconscious nature and integration with our other senses. Rare neurological disorders affecting proprioception highlight just how critical this sense is in our daily lives. The case of Ian Waterman – now known as ‘the man who lost his body – offers profound insights into the significance of proprioception (McNeill et al., 2009). Following a fever in 1971 at age 19, a subsequent auto-immune reaction destroyed all his sensory neurons from the neck down–a condition termed ‘neuronopathy’. Despite retaining his intact motor functions, Waterman lost all proprioceptive abilities, rendering him unaware of his body's position in space. Although the viral infection’s initial effect was that of immobility, this loss was not due to paralysis. Rather, it was Waterman’s lack of control over his body that inhibited his ability to move. Sitting, walking, and manipulating objects became impossible tasks as a result of the absence of any proprioceptive feedback from the body. Remarkably, Waterman has been able to teach himself precise strategies to walk and function with a degree of normality (Swain, 2017). Yet, all movement requires concerted planning and relies entirely on vision to compensate for the unconscious proprioceptive processing. In the absence of any light, Waterman is unable to see his limbs, thus restricting his ability to move. An understanding of the molecular mechanisms underlying proprioception remains somewhat of a mystery compared to that of our other senses. However, recent genetic advancements are paving the way for the development of novel therapies aimed at neurological and musculoskeletal disorders (Woo et al., 2015). A study involving two young patients with unique neurological disorders affecting their body awareness revealed a mutation in their PIEZO2 gene (Chesler et al., 2016). Both individuals experienced significant challenges with balance and movement, coupled with progressive scoliosis and deformities in the hips, fingers, and feet. The PIEZO2 gene typically encodes a type of mechanosensitive protein in cells, r esponsible for generating electrical signals in response to alterations in cell shape (Coste et al., 2010). Mutations to this gene prevent signal generation and render the neurons incapable of detecting limb or body movement. These findings firmly establish PIEZO2 as a critical gene for facilitating proprioception in humans, a sense that is crucial for bodily awareness. PIEZO2 mutations have also been implicated in genetic musculoskeletal disorders (Coste et al., 2010). Joint problems and scoliosis experienced by the patients in a study suggest that proprioception may also indirectly guide skeletal development. These insights into the role of the PIEZO2 gene in proprioception and musculoskeletal development open up promising avenues for understanding and treating neurological and musculoskeletal disorders. It’s more than fitting to regard proprioception as our sixth sense. The capacity of our nervous system to seamlessly process vast amounts of information from our joints and muscles, all without any conscious effort on our part, is truly remarkable. So, the next time you have that eyes-shut first sip of coffee, give yourself a pat on the back. With your sixth sense at play, you’re clearly a superhero! References Chesler, A. T., Szczot, M., Bharucha-Goebel, D., Čeko, M., Donkervoort, S., Laubacher, C., Hayes, L. H., Alter, K., Zampieri, C., Stanley, C., Innes, A. M., Mah, J. K., Grosmann, C. M., Bradley, N., Nguyen, D., Foley, A. R., Le Pichon, C. E., & Bönnemann, C. G. (2016). The Role of PIEZO2 in Human Mechanosensation. N Engl J Med , 375 (14), 1355-1364. https://doi.org/10.1056/NEJMoa1602812 Coste, B., Mathur, J., Schmidt, M., Earley, T. J., Ranade, S., Petrus, M. J., Dubin, A. E., & Patapoutian, A. (2010). Piezo1 and Piezo2 are essential components of distinct mechanically activated cation channels. Science , 330 (6000), 55-60. McNeill, D., Quaeghebeur, L., & Duncan, S. (2009). IW - “The Man Who Lost His Body”. In (pp. 519-543). https://doi.org/10.1007/978-90-481-2646-0_27 Proske, U., & Gandevia, S. C. (2012). The Proprioceptive Senses: Their Roles in Signaling Body Shape, Body Position and Movement, and Muscle Force. Physiological Reviews , 92 (4), 1651-1697. https://doi.org/10.1152/physrev.00048.2011 Sherrington, C. S. (1907). On the proprio-ceptive system, especially in its reflex aspect. Brain , 29 (4), 467-482. Swain, K. (2017). The phenomenology of touch. The Lancet Neurology , 16 (2), 114. https://doi.org/10.1016/S1474-4422(16)30389-1 Woo, S. H., Lukacs, V., de Nooij, J. C., Zaytseva, D., Criddle, C. R., Francisco, A., Jessell, T. M., Wilkinson, K. A., & Patapoutian, A. (2015). Piezo2 is the principal mechanotransduction channel for proprioception. Nature Neuroscience , 18 (12), 1756-1762. https://doi.org/10.1038/nn.4162 Previous article Next article Elemental back to

< Back to Issue 5 When Dark Matters Ingrid Sefton 24 October 2023 Edited by Celia Quinn Illustrated by Louise Cen To put it simply, the entire visible universe is huge. In the scheme of it, we really are just tiny dots on a floating rock, in a vast and constantly expanding cosmos. Yet, as it turns out, that’s not even close to the full story. All the visible objects, planets and galaxies contribute less than 15% of the mass in the universe. The other 85%? Nobody knows for certain, but it has a name. Dark matter. More can be said about what dark matter is not, than what it is. It isn’t the baryonic or “normal” matter such as protons, neutrons and electrons which comprise our visible world. It also isn’t antimatter, composed of subatomic particles with opposite charges to normal matter. Instead, dark matter interacts with normal matter in a manner entirely different to that of antimatter. It’s not a type of black hole, nor simply a form of radiation, or a type of massless particle. So, what can be conclusively said? Essentially, nothing. As the name suggests, dark matter emits no light and therefore is not visible in the way normal matter is, making it difficult to observe. In fact, dark matter has only been “observed” by way of its gravitational effects. Therefore, we know it must have mass in order to be able to interact with visible matter gravitationally. It’s also imperative for it to be big enough to cause the massive gravitational effects seen in galaxies (Lochner et al., 2005). Estimates place the mass-energy content of the cosmos as being composed of 26.8% dark matter, 68.3% dark energy and a relatively miniscule 4.9% normal matter (Greicius, 2013). The terms dark matter and dark energy are often thrown around somewhat interchangeably. However, they explain distinct aspects of observed gravitational and physical phenomena. Dark matter can be thought of as an invisible substance which is only seen through its effects on gravity - the unexplained gravitational forces that hold together rapidly rotating galaxies and stopping them from flying apart. Dark energy is then the force responsible for pushing these clusters of galaxies and the universe apart, accelerating the rate of expansion of the universe (NASA/WMAP Science Team, 2013). Given the lack of answers about what dark matter is, an interesting question to ponder is how its existence was even discovered. Swiss astronomer Fritz Zwicky was the first to propose the idea of “dark matter”. His observations of the Cloma galaxy cluster led him to suggest if individual galaxies within the cluster were only held together by the gravitational force of visible mass, the galaxies should fly apart due to their high velocity (American Museum of Natural History, 2000). He termed this mysterious force responsible for binding galaxy clusters together “dark matter”. It wasn’t until the 1970s that Vera Rubin became the first person to establish the existence of dark matter through her work with spiral galaxies. Spiral galaxies aren’t stationary. They rotate, with stars different distances from the centre moving in roughly circular orbits around this centre. The highest concentration of visible stars is found within the core region of a galaxy, leading to the assumption that the majority of mass, and therefore gravity, should also be concentrated there. An implication of this is the expectation that the farther a star is from this gravitational centre of a galaxy, the slower its projected orbital speed should be (American Museum of Natural History, 2000). However, alongside astronomer Kent Ford, Rubin made the puzzling observation that stars in both the centre and outer regions of any galaxy were moving at the same speed (American Museum of Natural History, 2000). Her calculations provided convincing observational evidence of Zwicky’s theory. The presence of a significant mass of invisible matter in the outer regions of a galaxy would create an even, spherical distribution of matter, gravitationally explaining the observed rotation of galaxies and their velocity distribution (NASA/WMAP Science Team, 2013). Fifty years later and experimental evidence still remains the only “proof” of dark matter we have, having been unable to directly detect dark matter. Despite this, a majority of scientists are confident in its existence. Rubin’s insight into the velocity distribution of galaxy rotation curves is amongst some of the most convincing observational evidence for the presence of dark matter. Also supporting its existence are the various discrepancies that arise in the process of gravitational lensing. Gravitational lensing occurs when an emitted source of light is deflected or distorted by the gravitational field of a large mass. Based upon the degree of deflection, the gravitational potential of the object can be calculated, alongside the amount of matter in the lensing object (Xenon Dark Matter Project, 2022). Yet, the strength of this gravitational lensing observed in many galaxy clusters is significantly greater than that calculated from visible matter alone. These inconsistencies point to the existence of unseen mass, or dark matter, as a convincing explanation for the observed lensing effects. It’s become clear that the standard model of physics, explaining the different particles and forces comprising the visible world, cannot be used in attempting to explain dark matter. In response, researchers are exploring a number of avenues to find hypothetical new particles. Amongst the most likely candidates for the composition of dark matter are two classes of particles: Weakly Interacting Massive Particles (WIMPs) and axions. WIMPs are distinguished as a class of particles created thermally in the early universe at very high temperatures, while axions originate predominantly from non-thermal mechanisms (Griest, 2002). Compared to WIMPS, or other known type of particles, axions would be thousands of times lighter but also significantly more abundant than WIMPs (Darling & Knight, 2022). Given the infinite potential to invent hypothetical substances that resolve the enigma of dark matter, experimentation to find these particles has significant challenges. Current research efforts are focused on the detection of such particles. More than a kilometre underground in Stawell, Victoria, the Stawell Gold Mine has been converted into an underground laboratory – one with no light, no noise, and no radioactivity to interfere with dark matter signals (Lippincott, 2023). Here, an experiment known as DAMA/Libra, which started in Italy in 1998, is being replicated. For two decades, what is suspected to be dark matter has been detected at the same time each year in Italy. The Stawell Lab is seeking to verify these results, operating below the equator to determine any potential effect of seasonal interference from the Earth (Darling & Knight, 2022). The research utilises the technology SABRE (Sodium iodide with Active Background REjection), which are sodium iodide crystals that emit flashes of light if a sub-atomic particle hits the nuclei of atoms within the crystals (Darling & Knight, 2022). Hence, if a particle of dark matter hits a nucleus, a tiny flash of light should be created. Simultaneously, researchers at the University of Western Australia have been working on the detection project ORGAN (Oscillating Resonant Group Axion), in order to determine the presence of axions (McAllister, 2022). Despite not having detected any dark matter signals thus far, such experimentation has still offered important insights. Not detecting dark matter within a certain mass range and level of sensitivity allows exclusion limits to be set around the possible characteristics of axions. This tells researchers where to stop looking and, instead, where they should be focusing their resources and efforts. Despite the disarray around “solving” the conundrum of dark matter, alongside its less than reassuring name, it’s not actually something that people should be scared about. The gravity that dark matter is responsible for enables our existence, with dark energy having allowed the expansion of the early universe to become what we see, and don’t see, today (Xenon Dark Matter Project, 2022). Detecting the presence of dark matter is about advancing our understanding of the size, structure, and future of the universe. Current research approaches may seem slightly haphazard, attempting to find something that has never been detected and may not even exist. But when pursuing strange cosmological phenomena beyond our understanding, taking a wild stab in the dark may be exactly what we need to do. References American Museum of Natural History (2000). Vera Rubin and Dark Matter . Retrieved September 1, 2023 from https://www.amnh.org/learn-teach/curriculum-collections/cosmic-horizons-book/vera-rubin-dark-matter Darling, A., & Knight, B. (August 20, 2022). The search for dark matter . ABC News. https://www.abc.net.au/news/2022-08-21/dark-matter-particle-physics-sabre-experiment-stawell-victoria/101113010 Greicius, T. (March 21, 2013). Planck Mission Brings Universe Into Sharp Focus. NASA. https://www.nasa.gov/mission_pages/planck/news/planck20130321.html Griest, K. (2002). WIMPs and MACHOs . In P. Murdin (Ed.), Encylopedia of Astronomy and Astrophysics: CRC Press. Lippincott, H. (August 9, 2023). Researchers dig deep underground in hopes of finally observing dark matter. The Conversation. https://theconversation.com/researchers-dig-deep-underground-in-hopes-of-finally-observing-dark-matter-211075 Lochner, J. C., Williamson, L., & Fitzhugh, E. (2005). Possibilities for Dark Matter. Retrieved August 29, 2023 from https://imagine.gsfc.nasa.gov/educators/galaxies/imagine/titlepage.html McAllister, B. (July 26, 2022). This Australian experiment is on the hunt for an elusive particle that could help unlock the mystery of dark matter. The Conversation. https://theconversation.com/this-australian-experiment-is-on-the-hunt-for-an-elusive-particle-that-could-help-unlock-the-mystery-of-dark-matter-187014 NASA/WMAP Science Team. (2013). WMAP produces new results . Retrieved September 13, 2023 from https://map.gsfc.nasa.gov/news/ Xenon Dark Matter Project. (2022). Dark Matter . Retrieved August 25, 2023 from https://xenonexperiment.org/partners/ Wicked back to

< Back to Issue 6 A Brief History of the Elements: Finding a Seat at the Periodic Table by Xenophon Papas 28 May 2024 Edited by Arwen Nguyen-Ngo Illustrated by Rachel Ko What are we made of and where did it all come from? Such questions have pervaded the minds of scientific thinkers since ancient times and have entered all fields of enquiry, from the physical to the philosophical. Our best scientific theory today asserts that we’re made of atoms, and these atoms come in different shapes and sizes. Fundamentally, they can be described by the number of subatomic particles (protons, neutrons, and electrons) they contain (Jefferson Lab, 2012). Neatly arranged in a grid, these different elements form the periodic table we know and love today; but it was not always this way. The story of how the periodic table of elements came to be harks back to Ancient Greece and winds its way through the enlightenment into the 20th century. It is an unfinished story of which we are at the frontier of today: in search of dark matter and the ultimate answer to what the universe is made of. We may never know for sure exactly what everything in existence consists of, but it’s a pursuit our earliest ancestors would be proud to see us follow. Thales was first in the ancient Greek-speaking world to postulate about the origins of all material things. He theorised that all matter in the universe was made up of just one type of substance – water – and any other forms of solids, liquids and gases were just derivatives thereof. This idea was not initially opposed, given Thales was one of the earliest of the Ancient Greeks to pursue such questions of a scientific nature. Afterall, he’s remembered today as the “Father of Science” in the Western world. As Thales was from Miletus, a city on the coast of the Ionian Sea in modern day Türkiye and part of Magna Graecia in the 6th cent BC, it is not hard to imagine that water was a crucial aspect in trade, agriculture, and daily life at the time. However, this seemed to oversimplify the matter to some of his contemporaries. Empedocles, who was considered more a magician than a philosopher, revised this mono-elemental theorisation in the 5th Century BC. He proposed four basic substances from which all others were made (Mee, 2020). We know them today famously as the four classical elements: Earth, Air, Water and Fire. This asserted a fundamental principle of “fourness”, encompassing the cardinal directions in the Western world during this time. Interestingly, concurrent to this other traditions such as those in China acknowledged five elements and compass points instead. A generation later to Empedocles’ work, Plato embraced his “fourish” formulation. Being heavily influenced by mathematics as the medium through which we make reason of the natural world, Plato related each of these elements to a mathematical object: a convex, regular polyhedron in three-dimensional Euclidean space, otherwise known as a Platonic solid. Earth was associated with the cube, air with the octahedron, water with the icosahedron, and fire with the tetrahedron. Lastly, the most complicated solid, the dodecahedron – itself made up of composite regular polygons – was associated with the makeup of the constellations and the Heavens themselves, their workings said to be unfathomable by human minds (Ball, 2004). His student, Aristotle, ran with this idea and devised a clever way to break up the elements based on their "qualities”, akin to a first periodic table. These binary roles were hot and cold, wet and dry, with an element containing just two of these qualities each. According to Aristotle, each of these elements could be converted to the other by inverting one of their qualities, seemingly bringing about an early form of alchemy. To these four elements, he also appended a fifth - aether or “pure air” - to fill the expanses of the heavens, which also became associated with the fifth Platonic solid. In the Western World, Aristotle’s word was taken as doctrine for a very long time owing greatly to the fall of Rome and the cultural instability thereafter. Where Europe plummeted into the Dark Ages with a reverence for the scholars of antiquity, scientific and literary endeavour flourished in the Middle East – the word alchemy itself having etymologically Arabic roots. It was not until the late 17th century that the likes of Galileo, Newton, and Descartes revived Western scientific pursuit, and sought to understand how the natural world arranged itself. In the 18th century, new discoveries were being made on the frontiers of science in major cities throughout Europe. In 1772, in Paris, Antoine Lavoisier began work on combustion of materials like phosphorus and sulphur. Lavoisier concluded that if something decomposes into simpler substances, then it is not an element. For example, while water can be turned into a gas when passed over hot iron and is therefore not an element, oxygen and hydrogen are indeed elemental. English chemist John Dalton took after Lavoisier and in 1808 began to arrange elements spatially into a chart, accounting for their various properties. In Strasbourg 1827, Wolfgang Döbereiner recognised that groups of threes arose from the list of elements which behaved similarly, known as “Döbereiner's triads" (Free Animated Education, 2023). John Newlands in 1866 put forward the “Law of Octaves”. Elements with similar properties ended up at regular intervals, dividing the elements into seven groups of eight – hence octaves. However, this method of dividing up the elements broke down in some special cases. Now turning to St. Petersburg, Russia, in February of 1869. Dmitri Mendeleev sits at his desk, with a mess of cards covering the surface of his working space. The professor of chemistry rearranges these elemental cards like a jigsaw puzzle, arranging and rearranging them to align them in accordance with their properties. Supposedly after coming to him in a dream, a pattern emerged. Mendeleev saw the ability for the simple tabulation of the elements based on their atomic number and hence their common properties. This newfound tool, based on Lavoisier’s work a century prior, allowed for the prediction of properties of elements which had not even been discovered yet. Elements which Mendeleev believed to exist, even though they presented as empty gaps in the grid structure of the periodic table. Within just twenty years, Mendeleev’s prediction of the existence of such elements like gallium, scandium, and germanium had been validated with experimental fact. All of this was predicted without knowledge of the true reason for similarities of elemental properties – the electron shell arrangement at a subatomic level. Mendeleev had totally changed the way chemists viewed their discipline and has been immortalised for perhaps the greatest breakthrough work in the history of chemistry (Rouvray, 2019). Today we recognise that all the elements in the universe have origins in the high-pressure hearts of stars. Like a hot furnace, they churn out heavier and heavier elements under their immense internal pressures. Once this life cycle comes to an end, the star erupts into a fiery supernova, releasing even more of the heavier elements we see further down the periodic table. In the last 75 years, scientists have added an additional 24 elements to the periodic table, some of which are so difficult to produce that their half-lives last only a few fractions of a millisecond before decaying away to nothing (Charley, 2012). This begs the question; how do we find new elements? Elements can be created via either fission, splitting apart a heavier atom, or fusion, binding two bodies of atoms together. The heavier an element, that is, the more protons and neutrons in its nucleus, the more unstable it is. Hence it is with great difficulty that scientists attempt to churn out new elements from large particle accelerators, by colliding and combining elements into new ones (Chheda, 2023). The story of physical matter is just one aspect in the search for what “everything” is made of. Dark matter and dark energy – so named because they do not interact with light – have been found to drive the expansion of the universe and the rotation speeds of galaxies. We know remarkably little about these substances, given that they make up around 95% of the total mass of the universe! Without a doubt, we have only just begun the journey to find out what makes up the universe around us. References Chheda, R. (2023, March 31). Can we add new elements to the periodic table? Science ABC. https://www.scienceabc.com/pure-sciences/can-we-add-new-elements-to-the-periodic-table.html Charley, S. (2012). How to make an element. PBS. https://www.pbs.org/wgbh/nova/insidenova/2012/01/how-to-make-an-element.html Free Animated Education. (2023, February 10). Perfecting the periodic table [Video]. YouTube. https://www.youtube.com/watch?v=7tbMGKGgCRA&ab_channel=FreeAnimatedEducation Jefferson Lab. (2012, November 20). The origin of the elements [Video]. YouTube. Ball, P. (2004). The elements: A very short introduction . Oxford University Press. Mee, N. (2020). Earth, air, fire, and water. In Oxford University Press eBooks (pp. 16–23). https://doi.org/10.1093/oso/9780198851950.003.0003 Rouvray, D. (2019). Dmitri Mendeleev. New Scientist. https://www.newscientist.com/people/dmitri-mendeleev Previous article Next article Elemental back to

< Back to Issue 2 Hiccups Evolution might be a theory, but if it’s evidence you’re after, there’s no need to look further than your own body. The human form is full of fascinating parts and functions that hold hidden histories - from the column that brought you a deep-dive into ear wiggling in Issue 1, here’s an exploration of why we hiccup! by Rachel Ko 10 December 2021 Edited by Katherine Tweedie and Ashleigh Hallinan Illustrated by Gemma Van der Hurk Hiccups bring a special brand of chaos to a day. It’s one that lingers, rendering us helpless and in suspense; a subtle, internal chaos of quiet frustration that forces us to drop what we’re doing to monitor each breath – in and out, in and out – until the moment they abruptly decide to stop. It’s an experience we’ve all had – one that can hit anyone at any time – and for most of us, hiccups are a concentrated episode of inconvenience; best ignored, and overcome. Yet, despite our haste to get rid of them when they interrupt our day, hiccups seem to have mystified humans for generations. Historically, the phenomenon has been the source of many superstitions, both good and bad. A range of cultures associate them with the concept of remembrance: in Russia, hiccups mean someone is missing you (1), while an Indian myth suggests that someone is remembering you negatively for the evils you have committed (2). Likewise, in Ancient Greece, hiccups were a sign that you were being complained about (3), while in Hungary, they mean you are currently the subject of gossip. On a darker note, a Japanese superstition prophesises death to one who hiccups 100 times. (4) Clearly, the need to justify everything, even things as trivial as hiccups, has always been an inherent human characteristic, transcending culture and time. As such, science has more recently made its attempt at objectively identifying a reason behind the strange phenomenon of hiccups. After all, if you take a step back and think about it, hiccups are indeed quite strange. Anatomically, hiccups (known scientifically as singultus) are involuntary spasms of the diaphragm (5): the dome-like sheet of muscle separating the chest and abdominal cavities. (6) The inspiratory muscles, including the intercostal and neck muscles, also spasm, while the expiratory muscles are inhibited. (7) These sudden contractions cause a rapid intake of air (“hic”), followed by the immediate closure of the glottis or vocal cords (“up”). (8) As many of us have probably experienced, a range of stimuli can cause these involuntary contractions. The physical stimuli include anything that stretches and bloats the stomach, (9) such as overeating, rapid food consumption and gulping, especially of carbonated drinks. (10) Emotionally, intense feelings and our responses to them, such as laughing, sobbing, anxiety and excitement, can also be triggers. (11) This list is not at all exhaustive; in fact, the range of stimuli is so large that hiccups might be considered the common thread between a drunk man, a Parkinson’s disease patient and anyone who watches The Notebook. The one thing that alcohol, (12) some neurological drugs (13) and intense sobbing (14) do have in common is that they exogenously stimulate the hiccup reflex arc. (15) This arc involves the vagal and phrenic nerves that stretch from the brainstem to the abdomen which cause the diaphragm to contract involuntarily. (16) According to Professor Georg Petroianu from the Herbert Wertheim College of Medicine, (17) many familiar home remedies for hiccupping – being scared, swallowing ice, drinking water upside down – interrupt this reflex arc, actually giving these solutions a somewhat scientific rationale. While modern research has successfully mapped out the process of hiccups, their purpose is still unclear. As of now, the hiccup reflex arc and the resulting diaphragmatic spasms seem to be effectively useless. Of the existing theories for the function of hiccups, the most prominent seems to be that they are a remnant of our evolutionary development, (18) essentially ‘vestigial’; in this case, a feature that once served our amphibian ancestors millions of years ago, but now retain little of their original function. (19) In particular, hiccups are believed to be a relic of the ancient transition of organisms from water to land. (20) When early fish lived in stagnant waters with little oxygen, they developed lungs to take advantage of the air overhead, in addition to using gills while underwater. (21) In this system, inhalation would allow water to move over the gills, during which a rapid closure of the glottis – which we see now in hiccupping – would prevent water from entering the lungs. It is theorised that when descendants of these fish moved onto land, gills were lost, but the neural circuit for this glottis closing mechanism was retained. (22) This neural circuit is indeed observable in human beings today, in the form of the hiccup central pattern generator (CPG). (23) CPGs exist for other oscillating actions like breathing and walking, (24) but a particular cross-species CPG stands out as a link to human hiccupping: the neural CPG that is also used by tadpoles for gill ventilation. Tadpoles “breathe” in a recurring, rhythmic pattern that shares a fundamental characteristic feature with hiccups: both involve inspiration with closing of the glottis. (25) This phenomenon strengthens the idea that the hiccup CPG may be left over from a previous stage in evolution and has been retained in both humans and frogs. However, the CPG in frogs is still used for ventilation, while in humans, the evolution of lungs to replace gills has rendered it useless. (26) Based on this information, it seems hiccupping lost its function with time and the development of the human lungs, remaining as nothing more than an evolutionary remnant. However, we cannot discredit hiccupping as having become entirely useless as soon as gills were lost. Interestingly, hiccupping has only been observed in mammals – not in birds, lizards or other air-breathing animals. (27) This suggests that there must have been some evolutionary advantage to hiccupping at some point, at least in mammals. A popular theory for this function stems from the uniquely mammalian trait of nursing. (28) Considering the fact that human babies hiccup in the womb even before birth, this theory considers hiccupping to be almost a glorified burp, intended to remove air from the stomach. This becomes particularly advantageous when closing the glottis prevents milk from entering the lungs, aiding the act of nursing. (29) Today, we reduce hiccups to the disorder and disarray they bring to our day. But, next time you are hit with a bout of hiccups, take a second to find some calm amidst the chaos and appreciate yet another fascinating evolutionary fossil, before you hurry to dismiss them. After that, feel free to eat those lemons or gargle that salty water to your diaphragm’s content. References Sonya Vatomsky, "7 Cures For Hiccups From World Folklore," Mentalfloss.Com, 2017, https://www.mentalfloss.com/article/500937/7-cures-hiccups-world-folklore. Derek Lue, "Indian Superstition: Hiccups | Dartmouth Folklore Archive," Journeys.Dartmouth.Edu, 2018, https://journeys.dartmouth.edu/folklorearchive/2018/11/14/indian-superstition-hiccups/. Vatomsky, "7 Cures For Hiccups From World Folklore". James Mundy, "10 Most Interesting Superstitions In Japanese Culture | Insidejapan Tours," Insidejapan Blog, 2013, https://www.insidejapantours.com/blog/2013/07/08/10-most-interesting-superstitions-in-japanese-culture/. Paul Rousseau, "Hiccups," Southern Medical Journal, no. 88, 2 (1995): 175-181, doi:10.1097/00007611-199502000-00002. Bruno Bordoni and Emiliano Zanier, "Anatomic Connections Of The Diaphragm Influence Of Respiration On The Body System," Journal Of Multidisciplinary Healthcare, no. 6 (2013): 281, doi:10.2147/jmdh.s45443. Christian Straus et al., "A Phylogenetic Hypothesis For The Origin Of Hiccough," Bioessays no. 25, 2 (2003): 182-188, doi:10.1002/bies.10224. Straus et al., "A Phylogenetic Hypothesis For The Origin Of Hiccough," 182-188. John Cameron, “Why Do We Hiccup?,” filmed for TedEd, 2016, TED Video, https://ed.ted.com/lessons/why-do-we-hiccup-john-cameron#watch. Monika Steger, Markus Schneemann, and Mark Fox, "Systemic Review: The Pathogenesis And Pharmacological Treatment Of Hiccups," Alimentary Pharmacology & Therapeutics 42, no. 9 (. 2015): 1037-1050, doi:10.1111/apt.13374. Lien-Fu Lin, and Pi-Teh Huang, "An Uncommon Cause Of Hiccups: Sarcoidosis Presenting Solely As Hiccups," Journal Of The Chinese Medical Association 73, no. 12 (2010): 647-650, doi:10.1016/s1726-4901(10)70141-6. Steger, Schneemann and Fox, "Systemic Review: The Pathogenesis And Pharmacological Treatment Of Hiccups," 1037-1050. Unax Lertxundi et al., "Hiccups In Parkinson’s Disease: An Analysis Of Cases Reported In The European Pharmacovigilance Database And A Review Of The Literature," European Journal Of Clinical Pharmacology 73, no. 9 (2017): 1159-1164, doi:10.1007/s00228-017-2275-6. Lin and Huang, "An Uncommon Cause Of Hiccups: Sarcoidosis Presenting Solely As Hiccups," 647-650. Peter J. Kahrilas and Guoxiang Shi, "Why Do We Hiccup?" Gut 41, no. 5 (1997): 712-713, doi:10.1136/gut.41.5.712. Steger, Schneemann and Fox, "Systemic Review: The Pathogenesis And Pharmacological Treatment Of Hiccups," 1037-1050. Georg A. Petroianu, "Treatment Of Hiccup By Vagal Maneuvers," Journal Of The History Of The Neurosciences 24, no. 2 (2014): 123-136, doi:10.1080/0964704x.2014.897133. Straus et al., "A Phylogenetic Hypothesis For The Origin Of Hiccough," 182-188. Cameron, “Why Do We Hiccup?” Michael Mosley, "Anatomical Clues To Human Evolution From Fish," BBC News, published 2011, https://www.bbc.com/news/health-13278255. Michael Hedrick and Stephen Katz, "Control Of Breathing In Primitive Fishes," Phylogeny, Anatomy And Physiology Of Ancient Fishes (2015): 179-200, doi:10.1201/b18798-9. Straus et al., "A Phylogenetic Hypothesis For The Origin Of Hiccough," 182-188. Straus et al., "A Phylogenetic Hypothesis For The Origin Of Hiccough," 182-188. Pierre A. Guertin, "Central Pattern Generator For Locomotion: Anatomical, Physiological, And Pathophysiological Considerations," Frontiers In Neurology 3 (2013), doi:10.3389/fneur.2012.00183. Hedrick and Katz, "Control Of Breathing In Primitive Fishes," 179-200. Straus et al., "A Phylogenetic Hypothesis For The Origin Of Hiccough," 182-188. Daniel Howes, "Hiccups: A New Explanation For The Mysterious Reflex," Bioessays 34, no. 6 (2012): 451-453, doi:10.1002/bies.201100194. Howes, "Hiccups: A New Explanation For The Mysterious Reflex," 451-453. [1] Howes, "Hiccups: A New Explanation For The Mysterious Reflex," 451-453. Previous article back to DISORDER Next article

< Back to Issue 4 PT by Saachin Simpson 1 July 2023 Edited by Caitlin Kane, Rachel Ko and Patrick Grave Illustrated by Jolin See 'Pt' (medical abbreviation for ‘patient’) recounts a patient visit on an early-morning ward round at Footscray Hospital in my first placement as a second-year medical student. The line “I came to hospital with my innocence” was actually said by the patient and stuck with me, eventually inspiring this poem, which I wrote in a Narrative Medicine class run by Dr Fiona Reilly and Dr Mariam Tokhi. The poem depicts a dramatic rise and fall in tension during the patient visit. It is bookended by soulless technical medical abbreviations that exemplify patient notes on electronic medical records. Pt Pt alert and oriented, sitting upright in chair. Breathing comfortably, responsive to questions. Bilat basal creps, bilat pitting oedema to knee. Pt gazes out window at the opposite concrete wall Pt’s cataracts suddenly shimmer, a sorcerer’s crystal ball. Pt need not speak for his stony grimace conveys Pt’s sheer and utter avowal of his final dying days. Pt’s power becomes apparent in his mighty ocular grip Pt’s lungs echo black tattered sails of a ramshackle timber ship. “I came to hospital with my innocence” Professional, qualified eyes dart from computer To patient And back. “and now I muse on dark and violent tricks” Med student looks at intern looks at reg looks at consultant. Feet shuffle, lips purse Pretending not to hear. “Your poisons gift no remedy, your words fat and hollow” Like a serpentine hiss, his derision rings through sterile air 5-step Therapeutic Guidelines for Reassurance (vol 23.4, updated 2023) does little for his despair. Pt need not speak for his stony grimace conveys Pt’s sheer and utter avowal of his final dying days. Pt need not speak for his stony grimace conveys Pt’s sheer and utter avowal of his final dying days. Pt to await GEM. Frusemide 40mmHg. Cease abx. Refer physio. Refer OT. Call family. For d/c Monday. Previous article Next article back to MIRAGE

< Back to Issue 8 In Your Dreams: Unpacking the Stories of Your Slumber by Ciara Dahl 3 June 2025 Edited by Ingrid Sefton Illustrated by Saraf Ishmam One minute you're flying through the sky, the next, you're naked in a room full of people. Except now, your teeth have started falling out? These surreal, and often illogical, experiences are what make dreams such a mystery. From ancient spiritual interpretations to modern neuroscience, people have long wondered not just what dreams mean , but why we have them at all. Are they cryptic messages from the unconscious? Perhaps a side effect of memory processing? Or maybe they are simply the brain’s way of entertaining itself while we sleep. Attempting to answer these questions is no easy feat. Despite being a universal human experience, dreams are inherently personal. Given no one but ourselves experiences our dreams, how can the fragmented recollections we have upon waking be objectively studied? Dream research was once steeped in spirituality and mysticism, often seen as divine messages from gods or whispered guidance from ancestors (1). Even Aristotle offered his own theory, suggesting dreams were the byproduct of internal bodily movements during sleep (1). It wasn’t until the early 20th century that dreams began to be studied through a psychological lens, most notably by Sigmund Freud, who proposed that dreams contained deeply personal and symbolic insights into the unconscious mind (2). Modern research, however, is beginning to uncover the connection between our dreams and complex cognitive processes such as memory consolidation. Techniques employed by oneirologists — that’s the fancy word for scientists specialising in the scientific study of dreams — includes fMRI, PET scans and EEG. Such methods are used to study brain activity during sleep and dreaming, particularly during REM and non-REM sleep (3). Using these technologies in tandem with qualitative descriptions gathered from individuals’ dream reports allows us to unpack the content and function of our dreams, whilst also considering questions such as why we seem to forget most of our dreams. What dreams are made of: influences on the content of our dreams There’s a growing body of evidence to suggest that our dream content is influenced by the consolidation of our memories as we sleep. Sleep provides an ideal neurological state for us to organise our recent memories into more long term memories (4). The reactivation and subsequent consolidation of memories in the sleeping brain appears to contribute to the content of dreams we recall upon awakening. In one study examining this phenomena, participants played extensive amounts of Tetris prior to sleeping. In the subsequent dream report collection, over 60% of participants cited seeing Tetris images in their dreams (5). This illustrates how the boundaries between waking and dreaming cognition are more porous than they appear, with dream content itself serving as a window into the neural mechanisms of memory consolidation. Not all dreaming can be directly tied to our most recent memories, but all dreams are built upon our prior experiences. For example, the appearance of recognisable friends or foes in our dreams in turn relies on our ability to recall their features and mannerisms (6). The bizarre patchwork of familiar situations we encounter in our dreams is also likely a reflection of the adaptive process of memory consolidation, as fragments of our memories are integrated during sleep. The Night Shift — what is the purpose of dreams We may be inching closer to understanding what influences the content of our dreams, but why do we dream in the first place? The Threat Simulation Theory (TST) argues that dreams act as an ancient biological defence mechanism, allowing us to simulate threatening events we may encounter in our waking life (7). TST suggests that on an evolutionary scale, being able to simulate threatening events in our sleep allows us to efficiently perceive and avoid threats whilst awake, leading to greater survival and reproductive success. It is a bit hard to imagine, however, that dreaming about being naked in public is going to be the key to our survival. This is why some scientists suggest that dreams are simply the brain’s attempt to make sense of random neural activity during REM sleep. This Activation-Synthesis Theory proposes that rather than rehearsing for real-life threats, our brains may just be firing off chaotic signals which it then tries to weave into bizarre and often disjointed stories (8). Whether dreams serve as a survival tool or are simply the byproduct of random brain activity, they offer a window into the complex workings of the sleeping mind. Vanishing Visions and the Concept of Dream Amnesia Have you ever woken up from such an absurd dream it seems impossible to forget, only to have forgotten the details by the end of breakfast? That’s what the experts call “dream amnesia”. It’s estimated that the average person dreams four to six times per night, yet you’d be lucky to remember even one of them by morning (6). At the molecular level, noradrenaline — a neurotransmitter associated with memory consolidation — is at its lowest concentrations while we sleep (9). This depletion could be a key factor contributing to dream amnesia, preventing the transfer of our dream experiences from short-term memory to long-term memory. Different sleep stages may also influence dream recall (6). It has been suggested that waking up during or just after REM sleep leads to more vivid dreams. In contrast, dream activity is low during non-REM sleep and hence, waking up during this sleep phase may also contribute to our poor dream recall. Although it can be disappointing to forget these wild dream experiences, dream amnesia may also serve an adaptive purpose. The “clean slate” hypothesis argues that forgetting dreams allows us to wake with a clear mind, free of the potentially disturbing content of our dreams (10). Alternatively, by maintaining a clear distinction between our dreaming and waking experiences, we are protected from confusing our dreams with reality, preventing anxiety that may otherwise ensue (11). Perhaps this forgetfulness may not be a flaw in our memory but a feature of it, helping us to preserve our mental clarity and emotional balance as we transition from the surreal world of our dreams to the demands of our waking life. In conclusion We may never fully unlock the secrets of our nightly adventures, but one thing is clear: dreams are a fascinating blend of memory, biology, and mystery. Whether they're ancient survival simulations, emotional clean-ups, or just the brain’s quirky way of entertaining itself while the lights are off, dreams remind us how wonderfully weird and complex the human mind truly is. Next time you find yourself tap dancing with Beyoncé or riding a roller coaster made of spaghetti, just enjoy the ride. Your brain is simply doing what it does best — keeping things entertaining, even in your sleep. References Palagini L, Rosenlicht N. Sleep, dreaming, and mental health: A review of historical and neurobiological perspectives. Sleep Medicine Reviews. 2011 Jun;15(3):179–86. Freud S. The Interpretation of Dreams [Internet]. 1900. Available from: https://psychclassics.yorku.ca/Freud/Dreams/dreams.pdf Ruby PM. Experimental Research on Dreaming: State of the Art and Neuropsychoanalytic Perspectives. Frontiers in Psychology [Internet]. 2011 Nov 18;2(286). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3220269/#B107 Wamsley EJ. Dreaming and offline memory consolidation. Current Neurology and Neuroscience Reports [Internet]. 2014 Jan 30;14(3). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4704085/ Stickgold R. Replaying the Game: Hypnagogic Images in Normals and Amnesics. Science. 2000 Oct 13;290(5490):350–3. Nir Y, Tononi G. Dreaming and the brain: from phenomenology to neurophysiology. Trends in Cognitive Sciences [Internet]. 2010 Jan 14;14(2):88–100. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2814941/ Revonsuo A. The reinterpretation of dreams: An evolutionary hypothesis of the function of dreaming. Behavioral and Brain Sciences [Internet]. 2000 Dec;23(6):877–901. Available from: https://pubmed.ncbi.nlm.nih.gov/11515147/ Hobson JA, McCarley RW. The brain as a dream state generator: an activation-synthesis hypothesis of the dream process. The American journal of psychiatry [Internet]. 1977 [cited 2019 Nov 14];134(12):1335–48. Available from: https://www.ncbi.nlm.nih.gov/pubmed/21570 Mitchell HA, Weinshenker D. Good night and good luck: Norepinephrine in sleep pharmacology. Biochemical Pharmacology. 2010 Mar;79(6):801–9. Eugene AR, Masiak J. The Neuroprotective Aspects of Sleep. MEDtube science [Internet]. 2015 Mar;3(1):35. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC4651462/ Zhao J, Schoch SF, Valli K, Dresler M. Dream function and dream amnesia: dissolution of an apparent paradox. Neuroscience and Biobehavioral Reviews. 2024 Nov 20;167. Previous article Next article Enigma back to

< Back to Issue 8 Cracking the Code: A Word from the Editors-in-Chief by Ingrid Sefton & Aisyah Mohammad Sulhanuddin 3 June 2025 Edited by Illustrated by May Du “Cogito, ergo sum.” I think, therefore I am . - René Descartes Is this, perhaps, the only fundamental truth? When we know with certainty that we are thinking, we recognise the ultimate proof of our existence. An absolute, some might say, in a world inherently characterised by doubt. Intuition has, and always will be, a powerful and compelling force driving our scientific exploration. That gut feeling of why or how or what is behind any given phenomena has been a catalyst for the innovation seen throughout millenia of scientific inquiry. Despite this, mere intuition is far from a reliable guide to making meaning of the world around us. Take the highly revered and long held notion of the “Spark of Life” – the supposition that a divine ‘spark’ was required for life and consciousness to be imbued in a human. While fascinating, fundamental scientific discoveries have since disproved such a mystical perception of life in exchange for far more logical, if perhaps less magical, biological explanations. Jumping to the present, and the collective effort of human minds have conceptualised and uncovered mechanistic explanations for so much of both human biology and the broader workings of our physical world. Where much life itself was once seen as an irreducible mystery, now come mapped abstractions of atoms to matter, cell division to DNA. The list forever goes on. But to return to our initial proposition – can we know anything with no whisper of a doubt, other than that we, in this moment, exist? What exists in the world around us? Much remains a mystery. How does this mystery propel us forward? What conclusions can we draw from the clues? How can we make sense of the corkboard, evidence bound by push pins and string? It’s no surprise that the enigmas of science draw the brightest, most inquisitive minds, eager to puzzle nature’s secrets and crack the codes of our existence. Thus , Enigma unravels how we yearn to explore, learn and piece together the scientific foundations of our world – even as we accept that we may never fully understand it. From the minute synaptic connections within our bodies, to the all encompassing wonder of the stars above, we are gripped by the need to know more. After all, human curiosity is only insatiable. So have on your tweed deerstalker, take a closer look through the magnifying glass, and follow the clues, if you dare. Charting the facets of our existence is life’s great challenge, and the game is indeed afoot! Previous article Next article Enigma back to