Category: today i learned (til)

Although it’s been about 4 months since the New Year, the start of summer is another perfect opportunity to get back on track with your new year’s resolutions. And this time, you’re going to stick to it because I’m going to explain the science behind your habits and how you can change your brain to change your habits. 

Scientifically, a habit is a routine, behavior, or cognitive process that starts spontaneously but is repeated automatically as a result of prior experience (Mendelsohn, 2020). It essentially means that it’s something you do without really thinking because you’ve done it before. For example, brushing your teeth as soon as you wake up, showering before bed, or grabbing a snack as soon as you get back to your apartment even if you’re not hungry. Habits are context dependent which means they are strengthened through repetition and use cues from the surrounding environment. When you perceive a cue, it automatically triggers a response without much cognitive input (Mendelsohn, 2020). In the example above, the cue is getting back to your apartment and your habit is grabbing a snack, because you’re normally hungry when you get back. But today, you ate a bigger lunch and even though you aren’t hungry you carried out your habit, why? 

The relationship between the cue and the response is strengthened by dopamine, the same molecule that keeps you scrolling on tiktok even though you have to wake up in 5 hours. This means that habits are strengthened and rewarded, urging you to carry them out over and over again. When you do something for the first time, your prefrontal cortex is highly active, aiding in carrying out complex cognitive behavior, attention, and decision making. As you continue to carry out the response, dopamine is released by two other brain regions known as the Ventral Tegmental Area (VTA) and Substantia Nigra (SNc). Here, dopamine helps facilitate learning by spiking the exact neural pathway carried out if an action is worth carrying out again or repeating. This strengthens the firing of those neurons in relation to one another, a process known as neuroplasticity (more on that later). Once the response has been reinforced with dopamine, it’s tagged for repetition which is facilitated by the corticostriatal loop which connects the cortex to the striatum, the part of the brain responsible for motor control and decision making. Over time, the brain starts to correlate the cue not the action with the reward leading to the automatic nature of habits. Finally, the striatum translates dopamine release into motor encoding so the output is not reliant on cognitive input and the prefrontal cortex but associations with contextual cues (Wyatt, 2024). 

This makes it seem like once a habit is formed, it’s an automatic response wired into us for good. Luckily, our brains are constantly evolving, rebuilding, and restructuring, a process known as synaptic plasticity. This means even though it may be hard, we can restructure, rebuild, and begin new habits. Neuroplasticity is the way the brain changes its activity in response to a stimulus by reorganizing its structure, functions, or connections. This can be carried out through a mechanism known as synaptic plasticity in which long-lasting changes are made to the connections between neurons. In order for this to occur, neurons must “fire together to wire together”(Puderbaugh & Emmady, 2023). At the cellular level, this change happens through synaptic plasticity. When neurons repeatedly fire together, they strengthen their connections, a concept known as “neurons that fire together wire together.” When one neuron activates another, it releases glutamate, an excitatory neurotransmitter. With repeated activation, receptors like AMPA and NMDA work together to increase the sensitivity of the receiving neuron. Over time, this makes the connection stronger, meaning the same signal produces a bigger response. This is how repeated behaviors become more efficient and automatic in the brain. This is obviously really cool science, but how do you use this to form new habits? 

It’s clear that habits require repetition whether it’s strengthening the synapses between neurons or the control of actions shifting from the prefrontal cortex to the striatum. But repetition can be hard when your brain has already been wired to do something different so here’s some tips to get your brain to repeat actions that aren’t yet habits until they become one. 

• Write down why your new habit made you feel good 

The reward pathway and dopamine are key players in why we carry out habits but unfortunately actions don’t feel like a reward until it’s been repeated over and over again. Taking time to think about why your new habit was a good one, and how it made you feel can release some of the “feel good” neurotransmitters and activate the same reward pathways that led to habit formation initially. 

• Habit stacking 

Stack new habits into a routine you already have. For example, if you always brush your teeth right when you wake up but forget to take your vitamins, start taking them right after you brush your teeth. This helps link the new behavior to already existing neural pathways making it easier to reinforce through repetition. 

• Start small 

Because your brain has wired your habits rendering them automatic, it takes a large cognitive load to override them. By starting small, you lessen the cognitive load and reduce the demand on the prefrontal cortex making it easier to start the task. For example, instead of saying you need to workout, start by saying you’ll go to the gym for 20 minutes. 

• Pay attention to cues 

Habit formation is highly cue dependent so start paying attention to the cues that trigger certain habits. The next time you see the cue, you are more likely to break the automatic control of the striatum and engage the decision making and cognitive processing of your prefrontal cortex. 

Although habit formation may seem hard, your brain is built to be changed if you let it. Now that you know the science behind changing your brain, the summer is a great time to start! 

Sources: 

Exploring the brain’s relationship to habits | nsf—U. S. National science foundation. (2013, January 14). https://www.nsf.gov/news/exploring-brains-relationship-habits

Mendelsohn, A. I. (2019). Creatures of habit: The neuroscience of habit and purposeful behavior. Biological Psychiatry, 85(11), e49–e51. https://doi.org/10.1016/j.biopsych.2019.03.978

Puderbaugh, M., & Emmady, P. D. (2026). Neuroplasticity. In StatPearls. StatPearls Publishing. http://www.ncbi.nlm.nih.gov/books/NBK557811/

Wyatt, Zoe. (2024). The Neuroscience of Habit Formation. Neurology and Neuroscience. 5. 3. 10.33425/2692-7918.1063. 

 

https://www.procreo.jp/labo/labo13.html

Watch this video. Do you see the dancer turning to the left?

Keep watching. Now, do you see her turning to the right?

The spinning dancer illusion has stumped viewers for years. Is the dancer actually changing directions, or is it just your brain playing tricks on you?

This video was made by a Japanese web designer named Noboyuki Kayahara in 2003 (Lucafò et. al. 2016).

Previously, I have talked about the concept of an image being multistable/bistable. Similar to images, this video can also be perceived as bistable because your brain can perceive the dancer as spinning in both the clockwise (CW) and counterclockwise (CCW) directions. Your brain maintains only one direction until prompted to switch because it settles on one interpretation until more evidence is accumulated to push it to change. In this case, my prompting you to look again would be sufficient evidence for your brain to look for a different visual interpretation of this video (Lucafò et. al., 2016).

In a study conducted by Bernal, it was found that a different hemisphere of the brain is activated for each iteration of the video (CW and CCW). This shows that different brain states are present for the subjective perception of a visual input. These differences in perception reflected spontaneous brain fluctuations in top-down sensory processing (Bernal et. al, 2014).

The ability of the brain to “flip” an interpretation of a visual input is a topic that has only been researched in recent years. The spinning dancer illusion is a simple and easy to measure and provides a strong basis for future studies in neural perception and attention.

References

Bernal, B., Guillen, M., & Marquez, J. C. (2014). The spinning dancer illusion and spontaneous brain fluctuations: An fMRI study. Neurocase, 20(6), 627-639.

Lucafò, C., Marzoli, D., Prete, G., & Tommasi, L. (2016). Laterality effects in the spinning dancer illusion: The viewing‐from‐above bias is only part of the story. British Journal of Psychology, 107(4), 698-709.

Every parent that’s watched their children play with dinosaurs have all had the same thought at one time or another: thank God dinosaurs are extinct. While the idea of dinosaurs seems mythical to some, paleontologists have determined their existence through fossils since the 1820’s. As technology advances, and paleontologists uncover more dinosaur fossils, the science world is realizing how crucial dinosaurs were to their ecological environment. To better understand what dinosaurs ate, paleontologists are transitioning from observing tooth structures to something most individuals may find repulsive or uncanny: fossilized feces, otherwise known as coprolites.

More specifically, paleontologists are currently studying a 26.5 inch coprolite- the largest recorded fossilized dung- of a Tyrannosaurus rex (T.Rex) to uncover what kind of organisms they preyed upon. The reason paleontologists are so keen on examining coprolites compared to other fossils is because dung structures provide an in-depth look into their diet. Karen Chin, a paleo-ecologist and professor at the University of Colorado describes the coprolite search to be fascinating, “…they’re basically like receipts of transactions of carbon resources that are traveling through an ecosystem” (Scott et.al, 2023). Dr. Chin’s analogy breaks down the concept of coprolites and gently nudges at the importance of the molecular structure within coprolites, which allows researchers like Dr. Chin to identify likely organisms part of the food web. 

Firstly, what does a coprolite consist of? In terms of their chemical composition, coprolites are mainly composed of calcium phosphate, a compound that allows the structure to be preserved (as they have been for millions of years). Externally, coprolites do not have a universal look- some are coiled or cylindrical while others have defined features that create an unwieldy look. Color wise, coprolites look…well one doesn’t need a description for that. As paleontologists continue studying the internal components of coprolites, a major breakthrough emerges. While analyzing coprolites of carnivorous dinosaurs, like the T.Rex and Spinosaurous, they discover intact bone fragments. This suggests that carnivorous dinosaurs ingested bones and that their digestive systems adapted to this lifestyle, as seen in the coprolites. Furthermore, coprolites are aiding scientific advancements in understanding the types of living organisms that lived during the Triassic to Cretaceous periods. Bone remnants have the potential to revolutionize how we comprehend dinosaur digestion in relation to their ecosystem.

The future implications of dinosaur coprolites are unimaginable; paired with the technology scientists develop for paleontologists to utilize, novel discoveries are on the up and coming. One of the many technological devices paleontologists are focusing on is the synchrotron microtomography, an X-ray machine that analyzes biological specimens (Sena et.al, 2022). These images provide paleontologists with a micro-analysis of the coprolites and make the process of tracking dietary habits easier. Not only can paleontologists identify the type of prey (animal or plant) but are able to answer the biggest question regarding dinosaurs: how did these creatures become the top predator of their food chain? 

The search for possible solutions led paleontologists to discover herbivores and their reign among the food chain. They’ve discovered that dinosaurs who acquired plant-based diets were surviving, reproducing, and growing in size. Essentially, as carnivorous dinosaurs converted to herbivores and made their palate diverse, by the Triassic period, they could adapt to any type of environment. Coprolites played a major role in revealing this fact by displaying trace fossils of the animals herbivores hunted. (Pattison 2024). Herbivore coprolites are proving to be indispensable in the paleontologist world- who knows what other mysteries could be solved as more coprolites emerge. For years paleontologists have observed fossilized dinosaur teeth and even vomit as the primary methods of identifying dietary patterns. Now, they utilize dinosaur coprolites, or dung, with the help of innovative technology that is paving the way for thorough research like never before.

References

Scott, A., McCoy, B., & Ramirez, R. (2023, November 24). What fossilized poop can teach us about dinosaurs. NPR. https://www.npr.org/2023/11/24/1198908684/dinosaurs-fossilized-poop-utah-dung-beetles-jurassic-park 

Brumfiel, G. (2024, November 27). Over 500 fossilized poops show how dinosaurs came to rule the Earth. NPR. https://www.npr.org/2024/11/26/nx-s1-5206634/fossilized-poops-show-how-dinosaurs-came-rule-earth#:~:text=A%20few%20years%20ago%2C%20he,were%20eating%20lots%20of%20stuff 

Sena G, Fidalgo G, Paiva K, Barcelos R, Nogueira LP, Colaço MV, Gonzalez MS, Azambuja P, Colaço G, da Silva HR, de Moura Meneses AA, Barroso RC. Synchrotron X-ray biosample imaging: opportunities and challenges. Biophys Rev. 2022 Jun 2;14(3):625-633. doi: 10.1007/s12551-022-00964-4. PMID: 35791381; PMCID: PMC9250583.

Pattison, K. (2024, November). Dino droppings reveal how the Giant Beasts came to dominate Earth | science | AAAS. Science. https://www.science.org/content/article/dino-droppings-reveal-how-giant-beasts-came-dominate-earth 

Science communication is an often-overlooked but very important part of furthering the scientific process, and both researchers and publishers often use graphical means to display experimental results and data through figures, as presenting data this way is considered standard within reporting results and finding as it is easily interpretable for a vast array of audiences. However, as a neuroscience student, both involved with research in a computational cognition and neuroAI lab and involved with STEM communication as a communications assistant for an institutional research institute, an interesting nuance to researchers’ use of graphs and figures to portray their results, both statistically, as the results of an experimental analysis, and methodologically, which shows their experimental process, is that while we think that we know what cognitive mechanisms people are using while interpreting these figures, in reality, the neural mechanisms are, for the most part, completely unexplored.

Inherently, almost anyone that you ask would believe that graph and figure comprehension is a visual task; however, research as recent as 2023 published by the National Eye Institute has shown that this might not be as true a heuristic – a mental shortcut or “cheat” that makes solving a problem easier – as initially thought. The National Eye Institute’s research showed that connections to the first region of the brain where visual information is processed, the primary visual cortex (V1), are rather small, accounting for between only 2 and 10 percent of neural connections that would be thought to inform us as to what we are perceiving. This is really interesting from a systems perspective in neuroscience, as this implies that what we are seeing only accounts for a relatively small portion of what we perceive. Therefore, in terms of graph and figure comprehension, the vast majority of neural connections are from other, non-visual,  regions of the brain, leading us to believe that our cognitive processing of graphs is largely a top-down process; a process where our understanding is heavily biased by prior experience and not what we are seeing in the moment.

From our understanding of the cognitive processes of how we interpret graphs and figures, many different brain regions could theoretically be responsible for this task; until neuroimaging research is done, we will never know for certain. However, one region of the brain that is non-visual and could be responsible for and contribute to our ability to understand information embedded within graphs is the language network and its associated regions. The language network is a portion of the brain made up of many distinct regions, such as Broca’s and Wernicke’s areas, which are commonly known to be involved with speech generation and understanding, respectively, that neuroscientists know contribute to our linguistic abilities. This region of the brain, along with other associated regions such as the cerebral cortex, suggested by some recent research in the context of semantics (Ivanova et. al., 2025), might play a large role in our ability to understand and interpret graphs and figures.

Additionally, research that has looked at large language models (LLMs), a form of artificial neural networks loosely modeled after how researchers understand the nervous system to process language, has interestingly shown that while really bad at processing graphs and figures, LLMs do technically use language to interpret and draw conclusions as to what they are looking at and pull from prior experience and reinforcement learning (Wang 2025).

Overall, because of this, I believe that our ability to process and understand graphs and figures would rely on another cognitive mechanism, such as language or semantics, for example, where we can “think through” and connect what we are observing in a figure to information that we already know – so this inherent visual task, may not be as much about seeing, as it is about knowing. In general, rephrasing this question to What is the neural basis of data visualization comprehension? to explore The Semantics of Data Visualization is a really interesting idea that sits at the intersection of computational cognition, neuroAI, and STEM communication.  

 

References

Ivanova, A. A., Kauf, C., Gao, R., She, J. S., Kean, H. H., Goldhaber, T., Nieto-Castañón, A., Varley, R., Kanwisher, N., & Fedorenko, E. (2025). Semantic reasoning takes place largely outside the language network (Version 1) [Preprint]. bioRxiv. https://doi.org/10.64898/2025.12.07.692873

National Eye Institute. (2023). Sparse, small, but diverse neural connections help make perception reliable, efficient. U.S. Department of Health and Human Services, National Institutes of Health. 

Wang, H. W., Wang, Z., Xu, Y., Chen, Z., Wu, Y., Qu, H., & Hullman, J. (2025). How aligned are human chart takeaways and LLM-generated insights? IEEE Transactions on Visualization and Computer Graphics. https://doi.org/10.1109/TVCG.2024.10681139

 

What’s the weirdest psychiatric condition you’ve ever heard of? Odds are, this one is infinitely stranger. Delusional Infestation (DI) is a condition in which a person falsely believes that their skin is infested with parasites, insects, bacteria, fungi, or other harmful items (Campbell et al. 2019). They often experience symptoms such as itchy or tingling sensations, or even feel something crawling on or under their skin, which further convinces them that the infestation is real. They may bring “specimens” of the parasites to show their doctors and remain unconvinced when told that the specimens are harmless objects or that medical tests have found nothing physically wrong with their skin.

The condition is also known as Delusional Parasitosis (DP), given that many people who have the condition attribute it to parasites. However, the terminology is changing in response to the fact that a wide variety of both living organisms and inanimate objects are blamed for symptoms (Bewley 2010).

Once it has been established that the person is not actually infested, they may be diagnosed with Delusional Infestation if:

• They have had the delusion for at least a month
• Aside from the delusion, their lives are mostly unimpaired
• Any mood episodes (mania or depression) that have occurred are brief compared to the duration of the delusion
• Their symptoms are not better explained by another physical or mental illness, including schizophrenia, or by substance use* (Campbell et al. 2019)

*If the case is primary DI; more on this in the next section

Causes

The cause of Delusional Infestation depends on the type of DI. Cases where DI is the only condition present are called primary DI. However, a person may also experience DI as a symptom of a different illness or due to the effects of certain drugs. In these situations, they are diagnosed with secondary DI because it is not the primary condition (Wikipedia Contributors 2019).

The cause of primary DI is currently unknown, though it may have something to do with the neurotransmitter dopamine. The presence of unusually high amounts of dopamine in certain brain regions can create formication, the skin-crawling sensation experienced by many people with DI, and faulty dopamine activity has also been implicated in other psychotic disorders like schizophrenia. However, research on this topic is still developing, making it impossible to draw conclusions at this time (Wikipedia Contributors 2019).

Secondary DI has quite a few potential causes. A vast range of physical medical conditions, from AIDS and hepatitis to traumatic brain injury and vitamin B12 deficiency, may cause delusions or crawling sensations (Reich et al. 2019, Wikipedia Contributors 2019). Consuming certain drugs, both legal and illegal, can also create similar effects. The side effects of some prescription drugs include DI, along with alcohol, cocaine, amphetamines, and cannabis (Campbell et al. 2019, Reich et al. 2019). Finally, other, more common mental conditions such as schizophrenia and depression may have symptoms that include DI.

Treatment

Thankfully, we know far more about treating DI than we do about its causes. Symptoms often respond well to antipsychotic medications, and in the case of secondary DI, they may vanish entirely when the person receives treatment for their primary condition (Campbell et al. 2019).

Unfortunately, treatment of Delusional Infestation is often difficult, as by definition, people with DI believe that they have a physical illness, not a mental one. DI cases most often begin in the offices of dermatologists, parasitologists, and entomologists instead of psychiatrists. Upon being shown evidence that their condition is not physical (such as negative test results or proof that a specimen is ordinary detritus), a person may simply leave and go to a different doctor in an attempt to get the diagnosis they want. Recent discussions of DI among researchers and health care professionals have emphasized the importance of collaboration between a person’s doctors and maintaining a positive relationship with patients (Reich et al. 2019, Campbell et al. 2019). These measures can persuade some people with DI to agree to psychiatric treatment, but others may refuse to accept it no matter what.

Potential Harms

Many friends, relatives, and doctors who have seen the effects of Delusional Infestation become frustrated by their inability to persuade the affected person of the reality of their illness. At the same time, it is important to encourage DI patients to accept treatment, as the condition is not harmless. The most obvious problem caused by DI is the stress and mental suffering caused by the symptoms themselves – no one enjoys feeling like they have bugs inside their body! People with DI sometimes scratch or pick at their skin, potentially causing more issues. The symptoms and delusions may also cause problems at work and in social relationships. In rare cases, people with DI may harm themselves, other people, or pets in the course of attempts to get rid of the “infestation” (Shelomi 2026).

A further danger exists in the form of people and organizations who, despite the seriousness of this condition, take advantage of vulnerable people with DI in order to gain money from them. There are multiple pseudoscientific diagnoses promoted in low-quality research and on the Internet that emphasize DI symptoms but cruelly encourage the delusion that the condition has a physical cause. Scary-sounding terms like “Morgellons Disease” and “Neurocutaneous Syndrome” are marketed to the public in order to promote the services of a sketchy doctor or sell a miracle cure (Shelomi 2026). Belief in these false diseases can prevent a person from getting real treatment or unnecessarily prolong their suffering by prompting them to chase after false cures for lengthy periods of time when they could have received help right away.

Overall, Delusional Infestation is an interesting condition that exposes a number of phenomena related to the current state of science and medicine in our society. The need for more effective communication regarding rare conditions, the importance of trust between patients and doctors, and the prevalence of scammers that prey on vulnerable demographics are all important issues that deserve greater examination. DI demonstrates a complicated and strange relationship between our brains and bodies and exposes gaps in our knowledge of medicine and psychiatry. Hopefully in the future, it will get the attention it deserves in the form of more research into its causes and more effective treatments for those who suffer from its symptoms.

 

Sources:

Bewley, A.P., et al. “Delusional Parasitosis: Time to Call It Delusional Infestation.” British Journal of Dermatology, vol. 163, no. 1, 22 Feb. 2010, pp. 1–2, https://doi.org/10.1111/j.1365-2133.2010.09841.x

Campbell, Elliott H., et al. “Diagnosis and Management of Delusional Parasitosis.” Journal of the American Academy of Dermatology, vol. 80, no. 5, May 2019, pp. 1428–1434, www.sciencedirect.com/science/article/pii/S0190962218330548, https://doi.org/10.1016/j.jaad.2018.12.012

Reich, Adam, et al. “Delusions of Parasitosis: An Update.” Dermatology and Therapy, vol. 9, no. 4, 13 Sept. 2019, pp. 631–638, www.ncbi.nlm.nih.gov/pmc/articles/PMC6828902/, https://doi.org/10.1007/s13555-019-00324-3

Shelomi, Matan. “Delusion or Dentistry: The Pseudoscientific Diagnosis of Neurocutaneous Syndrome | Skeptical Inquirer.” Skepticalinquirer.org, 4 Mar. 2026, skepticalinquirer.org/exclusive/delusion-or-dentistry-the-pseudoscientific-diagnosis-of-neurocutaneous-syndrome/

Wikipedia Contributors. “Delusional Parasitosis.” Wikipedia, Wikimedia Foundation, 16 July 2019, en.wikipedia.org/wiki/Delusional_parasitosis