Decoding our Perception of Smell

Scientists have already established a relatively strong connection between certain sensory inputs and their corresponding brain activity patterns [1]. With the use of devices like functional Magnetic Resonance Imaging (fMRI), they can directly measure electrical changes in the brain as a person is sensing or thinking about something [2]. While this is useful for identifying which parts of the brain are related to certain activities and evaluating new connections between areas of the brain, scientists have long struggled to identify which aspects of these patterns are important for perception. Since many features of brain patterns have been identified as redundant or ‘epiphenomenal’ [3], an understanding of the relative importance behind each aspect of these brain activity patterns would give us a valuable insight into the neurological mechanisms behind perception.

One area that scientists have explored this connection is in our perception of smell — primarily regarding how our brains process the electrical signals they receive from the olfactory bulb (the ‘hub’ of olfactory receptors). Scientists already understood that certain airborne molecules trigger receptors in the olfactory bulb, leading to a cascade of signals and eventually the sensation of smell; however, very little was previously known about how these complex patterns resulting from the airborne molecules actually contribute to our perception of odors [1].

Scientists at the NYU Grossman School of Medicine chose to explore this idea with genetically modified mice. The researchers in this study used mice that were engineered so that their brain cells could be activated by light (optogenetics), and then tested different patterns of stimuli to determine which aspects of the pattern most affected their perception of the odor. Because the olfactory receptors in the mice could be stimulated by light, scientists were essentially able to create ‘synthetic smells’ by designing their own patterns and timing of light-based stimuli. They trained the mice to pull a lever when exposed to one of these ‘synthetic smells’ and then systematically altered the pattern of stimuli to determine which alterations had the greatest impact on how well the mice could perceive the scent [3].

From this study, the scientists concluded that two main factors affect the perception of smell in mice: the type of receptor stimulated and the rhythmic timing of those stimuli. For example, they found that changes to cells stimulated earlier in the cascade of signals had a more significant effect on perception than cells stimulated later in the sequence. They used observations like this, in addition to a multitude of other data, to develop a computational framework that decoded the complex perceptual patterns of the mouse olfactory system. With this model, researchers can find direct links between brain activity and perception, advancing the capacity of scientists to develop technology aimed at manipulating perception [1].

Scientists already have a pretty good understanding of brain activity patterns and perception — but the connections between these concepts are still largely unknown. Decoding the pathways between neural activity and behavioral changes in mice is just one piece of this complicated puzzle.

References:

[1] Chong, E., Moroni, M., Wilson, C., Shoham, S., Panzeri, S., & Rinberg, D. (2020). Manipulating synthetic optogenetic odors reveals the coding logic of olfactory perception. Science, 368(6497), eaba2357. https://doi.org/10.1126/science.aba2357

[2] How do Scientists Study the Brain? (n.d.). Dana Foundation. Retrieved November 5, 2020, from https://www.dana.org/article/how-do-scientists-study-the-brain/

[3] NYU Langone Health / NYU School of Medicine. "Scientists decode how the brain senses smell." ScienceDaily. ScienceDaily, 18 June 2020. <www.sciencedaily.com/releases/2020/06/200618150304.htm>.

The World of Psychodermatology

What is Psychodermatology?

Psychodermatology is a field of medicine that explores the effect of psychocutaneous conditions or disorders on the health of your skin, hair, and/or nails. The field is not yet widely researched, but is reported to be somewhat common. In fact, according to a study on Psychodermatology by Brown et.al, one-third of patients who’ve suffered from dermatologic diseases have underlying psychiatric conditions and the field of psychodermatology could suggest that the two conditions may be directly related, where one causes or worsens the other [1].

How does the way we look affect the way we feel?

In Dr. Linda Papadopoulos’ TED talk, ‘Psychodermatology: More Than Skin Deep’ , Papadopoulous describes her findings that people’s skin conditions often occur because of stressful life events, which can be explained by the embryological connection between nerve endings and the skin giving chronic stress the ability to “disrupt the function of skin’s permeability.” [2]  

In the paper Psychodermatology: When the Mind and Skin Interact, Dr. Mohammad Jafferany goes more in-depth with the relationship between stress and skin and explains how stress activates both the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system pathways [3]. External stress causes these two pathways to release catecholamines and cortisol, both of which have a significant effect on the immune system by going through a series of activities which conclusively “tilts the balance toward humoral immunity and activates B cells, mast cells, and eosinophils, with a consequent increase in allergic inflammatory response” [3].

This inflammatory response then leads to issues in the skin, most of which can be distinguished by three types, as outlined by Koo and Lee [4].

First, psychophysiological disorders are skin diseases that appear to be precipitated or exacerbated by stress. Disorders classified within this group take an especially relevant emotional and social toll on patients, as their self-view becomes significantly harmed, and they become much less likely to practice self-care and seek social interaction [4]. 

Second, psychiatric disorders with dermatological symptoms include disorders that are purely self-inflicted, through actions which include scratching, picking at the skin, or hair-pulling, due underlying psychopathology [4].

Lastly, diseases can be classified as dermatological disorders with psychiatric symptoms which affect patients who have emotional problems due to having skin disease. These skin diseases tend to be more serious than the others, with much more severe physical symptoms that are more likely to be fatal or have life ruining effects [4].

The Resulting Cycle

For a patient, the interwovenness between stress, or mental health, and the severity of skin conditions creates a never-ending cycle. On a personal level, this essentially being “the worse my skin gets, the worse I feel and the worse I feel, the worse my skin gets” [2]. Disrupting the moment in the cycle where we deny ourselves care, could allow doctors to acknowledge the root of the issue instead of treating its symptoms, and patients could be given tools to help avoid defining themselves by their skin condition, reducing stress and increasing the chance of healing or decreasing the chance of it worsening. Dr. Jaffereany specifically states solutions of “separate psychodermatology clinics, training opportunities for physicians and residents in psychiatry and dermatology residency programs, and family education” to do so [3].

References: 

[1] Brown, G. E., Malakouti, M., Sorenson, E., Gupta, R., & Koo, J. Y. (2015). Psychodermatology. Advances in psychosomatic medicine https://doi.org/10.1159/000369090 (accessed Nov 6, 2020)

[2] Papadopoulos , L. Psychodermatology: More Than Skin Deep. TEDxUniversityofManchester.https://www.youtube.com/watch?v=ELHrtqvmu6Q&ab_channel=TEDxTalks (accessed Nov 8, 2020)

[3] Jafferany M. (2007). Psychodermatology: a guide to understanding common psychocutaneous disorders. Primary care companion to the Journal of clinical psychiatry https://doi.org/10.4088/pcc.v09n0306 (accessed Nov 7, 2020)

[4] Nguyen, C. M. K.; Danesh, M.; Berokhim, K.; Sorenson, E.; Leon, A.; Koo, J. Psychodermatology: A Review. Practical Dermatology (2015) https://practicaldermatology.com/articles/2015-may/psychodermatology-a-review  (accessed Nov 8, 2020)

[5] DeFino, J. The Burgeoning Field of Psychodermatology Explores the Link Between Mental Health and Skin. https://fashionista.com/2019/06/psychodermatology-mental-health-skin-care (accessed Nov 7,  2020). 

The Secret Mineral Hidden on Plant Leaves

What do experimental cancer-fighting drugs, inkjet printing, and a small lineage of alpine plants have in common? Apparently, they share a rare and enigmatic mineral called vaterite.

In the past few years, scientists at Cambridge University have made an esoteric but potentially game-changing discovery: small crystal formations on the leaves of a certain plant species contain novel amounts of vaterite. Cambridge gardens have long been host to particularly tenacious group of plants in the genus Saxifraga, which in nature are most commonly found in the harsh upper altitudes of mountain ecosystems [1]. Researchers are interested in these plants due to their unique adaptations that allow them to survive the harsh winds and extreme temperatures in their natural habitats. One such trait, found in Saxifraga sempervivum, is a protective crystal crust that forms on the leaf surfaces. Although this calcium carbonate crust exists on multiple species of Saxifraga, only on S. sempervivum does the specific form (called a polymorph) of the carbonate exist as pure vaterite. The mineral forms from the chalky crust-producing glands on the edges of fleshy leaves of small alpine plants and may possibly benefit these leaves with thermal insulation [2].

Vaterite is notable for several reasons, the first being how rare it is to find in nature. It is seen occasionally in meteorites and can be produced in small quantities as a biomineral by certain crustaceans, birds, and fish [2]. This scarcity is unsurprising given that vaterite is also the most unstable of all calcium carbonate polymorphs – even minimal exposure to water is usually enough to transform it into another carbonate [3]. As such, its temperamental qualities, scattered occurrences, and miniscule volume when produced should have pushed the mineral to the wayside of current scientific research – but this isn't the case. Difficulties in procuring it aside, vaterite has proven to have several valuable and uncommon properties as a mineral. Unusual solubility, high loading capacity, and a high rate of uptake by cells have piqued interest in the polymorph from researchers and inventors alike[1].

Given the uniqueness of these properties in combination of one mineral, vaterite has the potential to be widely profitable in multiple industries. For instance, it can be used as a binding agent in cosmetic products, a template for biodegradable polymers, and a superior coating pigment for inkjet printing [3]. Yet, even more impressive is the potential of vaterite in medicine, especially as a tool for cancer-fighting pharmaceuticals. Here, its value lies in the ability of its nanoparticles to load up on anti-cancer drugs and then systematically offload those agents at targeted cancer sites – essentially a top-notch drug-delivery service [1].

Of course, all these hypothetical applications have been fruitless given the scarcity and instability of vaterite in nature, as well as the difficulties in mass-producing it in a lab. But the discovery of its pure form in Saxifraga could be a game-changer. Not only is this the first instance of the mineral appearing in plants, but it is also the largest quantity of vaterite production seen in nature yet [2]. As a result, many scientists are strongly optimistic about vaterite’s future in medical and industrial technology – all thanks to one unassuming alpine plant.

References:

[1] Grube, K. A rare mineral with potential industrial and medical applications has been discovered on alpine plants at Cambridge University Botanic Garden, 2018. University of Cambridge. https://www.cam.ac.uk/research/news/rare-mineral-discovered-in-plants-for-first-time (accessed November 1, 2020).

[2] Konopacka-Łyskawa, D. Synthesis Methods and Favorable Conditions for Spherical Vaterite Precipitation: A Review. Crystals 2019, 9, 223-241.

[3] Wightman, R.; Wallis, S.; Aston, P. Leaf margin organization and the existence of vaterite-producing hydathodes in the alpine plant Saxifraga scardica. Flora 2018, 241, 27-34.

Image: Pettinger, B. Saxifraga sempervivum; 2012. Flickr Creative Commons.

The Asian Glow Explained

Turning red after drinking an alcoholic beverage with some friends is not a good thing. In fact, it indicates that your body is unable to efficiently process alcohol. Often referred to as the “Asian Glow” or the “Asian Flush,” this condition is due to a deficiency of the aldehyde dehydrogenase 2 enzyme (ALDH2) and affects approximately 30-50% of East Asians [1]. Typically, when alcohol is ingested, there are two main enzymes that the body uses to metabolize alcohol: alcohol dehydrogenase and aldehyde dehydrogenase.  First, alcohol dehydrogenase will convert the alcohol into acetaldehyde, a toxic chemical. Then, aldehyde dehydrogenase 2 breaks down the toxic acetaldehyde into the non-toxic compounds acetate and water [2]. Those who have the “Asian Glow” are missing this critical second enzyme, which results in an accumulation of acetaldehyde. The build-up of acetaldehyde causes blood vessels to dilate, which gives those with the Asian Glow the characteristic facial redness. Additionally, it can cause a rapid heartbeat, nausea, headaches, itchiness, red eyes, difficulty breathing, and many other not-so-fun symptoms [2]. 

What most people don’t know is that acetaldehyde is a carcinogen: it causes cancer. In fact, in a series of studies done by Akira Yokoyama and his colleagues in Japan comparing individuals with a functional ALDH2 gene to those with an inactive variant, they showed that individuals with a copy of the inactive variant of the gene for ALDH2 were 6-10 times more likely to develop esophageal cancer than are those with the fully functioning ALDH2 enzyme who drink similar amounts of alcohol [3]. Furthermore, individuals with the inactive ALDH2 enzyme who drink 33 or more U.S. standard drinks per week are at an eighty-nine-fold higher risk of esophageal cancer compared to a non-drinker with an inactive enzyme [3].

It might seem unusual that such a large population of East Asians specifically are affected by this odd condition. How would something like this start? The answer may be quite simple: rice. The first cases of the Asian Glow were reported 10,000 years ago, which corresponds to when humans first began cultivating rice. Researchers hypothesize that the genetic mutation that causes an adverse reaction to alcohol consumption arrived to protect early farmers from  negative effects of alcohol use [4]. 

Unfortunately, there is no currently-known cure for the negative effects of the Asian Glow. Some have resorted to taking antihistamines to reduce the redness. Antihistamines reduce or block histamines, the compound that dilates blood vessels and results in the reddening of the face. The body turns red for a reason: acetaldehyde is in its system. The redness is the body’s way of indicating that it’s being damaged. Therefore, reducing the redness not only proves ineffective in treating the negative health effects of the Asian Glow, but also may mask the body’s natural immune response [5]. The best way to deal with the Asian Glow is not to drink. Nevertheless, drinking is a very common behavior in today’s society, so I leave you with this message: everything in moderation. 

What most people don’t know is that acetaldehyde is a carcinogen: it causes cancer. In fact, in a series of studies done by Akira Yokoyama and his colleagues in Japan comparing individuals with a functional ALDH2 gene to those with an inactive variant, they showed that individuals with a copy of the inactive variant of the gene for ALDH2 were 6-10 times more likely to develop esophageal cancer than are those with the fully functioning ALDH2 enzyme who drink similar amounts of alcohol [3]. Furthermore, individuals with the inactive ALDH2 enzyme who drink 33 or more U.S. standard drinks per week are at an eighty-nine-fold higher risk of esophageal cancer compared to a non-drinker with an inactive enzyme [3].

It might seem unusual that such a large population of East Asians specifically are affected by this odd condition. How would something like this start? The answer may be quite simple: rice. The first cases of the Asian Glow were reported 10,000 years ago, which corresponds to when humans first began cultivating rice. Researchers hypothesize that the genetic mutation that causes an adverse reaction to alcohol consumption arrived to protect early farmers from  negative effects of alcohol use [4]. 

Unfortunately, there is no currently-known cure for the negative effects of the Asian Glow. Some have resorted to taking antihistamines to reduce the redness. Antihistamines reduce or block histamines, the compound that dilates blood vessels and results in the reddening of the face. The body turns red for a reason: acetaldehyde is in its system. The redness is the body’s way of indicating that it’s being damaged. Therefore, reducing the redness not only proves ineffective in treating the negative health effects of the Asian Glow, but also may mask the body’s natural immune response [5]. The best way to deal with the Asian Glow is not to drink. Nevertheless, drinking is a very common behavior in today’s society, so I leave you with this message: everything in moderation. 

References:

1. Lin, Y. (2017, May 3). The Quad: Understanding 'Asian glow' and how to counteract it. Retrieved November 05, 2020, from https://dailybruin.com/2017/05/03/the-quad-understanding-asian-glow-and-how-to-counteract-it

2. Cheong, T. (n.d.). Food Tips. Retrieved November 05, 2020, from https://www.healthxchange.sg/food-nutrition/food-tips/asian-flush-alcohol-red-face

3. Alcohol Flush Signals Increased Cancer Risk among East Asians. (2015, October 22). Retrieved November 05, 2020, from https://www.nih.gov/news-events/news-releases/alcohol-flush-signals-increased-cancer-risk-among-east-asians

4. Huai, E. (2019, September 26). Asian Flush (Alcohol Flush Reaction): Cures, Symptoms, Causes & Health Risks. Retrieved November 05, 2020, from https://www.flyby.co/blogs/news/asian-flush

5. Vuong, Z. (2018, August 06). Antihistamines prevent 'Asian flush' - alcohol-induced facial redness - but pose risks. Retrieved November 05, 2020, from https://news.usc.edu/112489/antihistamines-prevent-asian-flush-the-red-face-some-people-get-from-alcohol-but-with-huge-risks/

A Market for Merriment: Three Ways to Shop for Happiness

Shopping is a pastime that many people turn to when they feel stressed or overwhelmed, which can lead to regrettable purchases. Thankfully, there are ways you can engage in retail therapy and feel great about what you buy–here are three ways that you can spend money to boost your happiness, with evidence from psychology research from all over!

Tip #1: Invest in experiences

One of the ways that you can spend money to increase your happiness is to invest in experiences, like going to a concert or going on vacation, rather than on material goods like jewelry or clothes. One reason is that we may identify more with our experiences than with our material possessions. In a series of studies where participants considered the purchases they have made in relation to their sense of self, Carter and Gilovich found that, overall, participants felt  that their experiences, rather than material goods, were more connected to their sense of self [1]. We may also feel more grateful for these experiences. Looking at undergraduate students and online reviews, Walker, Kumar, and Gilovich found that participants were more grateful for their experiences than for their material possessions [2]. Finally, it might be worth bringing along a friend–Caprariello and Reis looked at undergraduate and online participants’ attitudes towards their purchases and found that participants preferred experiences that they shared with others over material purchases or experiences that they had alone [3].

Tip #2: Spend on others

Spending on others comes with several benefits. For instance, spending money on others feels good–Aknin et al. found that, looking at people across 136 countries and a wide range of income levels, spending money on others was associated with greater happiness [4]. Spending on others may also be good for your health. Whillans et al. found that older adults with high blood pressure who spent money on others for three weeks had lower blood pressure than those who spent money on themselves [5]. Finally, spending money on others can benefit the person receiving the gift. Zhang et al. asked participants recruited on a survey platform to recall an instance when someone bought something for them and found a relationship between participants’ willingness to accept (WTA) the gift and their reported subjective well-being (SWB), with the gift’s attractiveness and positive perceived intention of giving being related to SWB via WTA [6].

Tip #3: All sales final

Many stores offer warranties and return policies to protect consumers and their goods. These are appealing because they make the decision reversible–people tend to prefer reversible decisions because they bring about feelings of freedom and act as a safety net [7]. However, people may actually end up unhappier as a result of making reversible decisions. In a study where students performed a series of decision-making tasks, Bullens et al. found that reversible decision-making led to lower levels of satisfaction afterwards and also that making reversible decisions may lead to focusing on negative aspects of the choice while making irreversible decisions may result in focusing instead on positive aspects that make the choice appealing [8]. The next time you go shopping, consider skipping out on the warranties and return policies, especially if they cost you extra. You might end up spending more money to make a decision that you will ultimately be less happy with.

References:

1. Carter, T. J.; Gilovich, T. I Am What I Do, Not What I Have: The Differential Centrality of Experiential and Material Purchases to the Self. J. Pers. Soc. Psychol. 2012, 102 (6), 1304–1317. https://doi.org/10.1037/a0027407.

2. Walker, J.; Kumar, A.; Gilovich, T. Cultivating Gratitude and Giving through Experiential Consumption. Emotion 2016, 16 (8), 1126–1136. https://doi.org/10.1037/emo0000242.

3. Caprariello, P. A.; Reis, H. T. To Do, to Have, or to Share? Valuing Experiences Over Material Possessions Depends on the Involvement of Others. J. Pers. Soc. Psychol. 2013, 104 (2), 199–215. https://doi.org/10.1037/a0030953.

4. Aknin, L. B.; Barrington-Leigh, C. P.; Dunn, E. W.; Helliwell, J. F.; Burns, J.; Biswas-Diener, R.; Kemeza, I.; Nyende, P.; Ashton-James, C. E.; Norton, M. I. Prosocial Spending and Well-Being: Cross-Cultural Evidence for a Psychological Universal. J. Pers. Soc. Psychol. 2013, 104 (4), 635–652. https://doi.org/10.1037/a0031578.

5. Whillans, A. V.; Dunn, E. W.; Sandstrom, G. M.; Dickerson, S. S.; Madden, K. M. Is Spending Money on Others Good for Your Heart? Health Psychol. 2016, 35 (6), 574–583. https://doi.org/10.1037/hea0000332.

6. Zhang, W.; Chen, M.; Xie, Y.; Zhao, Z. Prosocial Spending and Subjective Well-Being: The Recipient Perspective. J. Happiness Stud. 2018, 19 (8), 2267–2281. https://doi.org/10.1007/s10902-017-9918-2.

7. Bullens, L.; Harreveld, F. Second Thoughts about Decision Reversibility: An Empirical Overview. Soc. Personal. Psychol. Compass 2016, 10 (10), 550–560. https://doi.org/10.1111/spc3.12268.

8. Bullens, L.; van Harreveld, F.; Förster, J.; van der Pligt, J. Reversible Decisions: The Grass Isn’t Merely Greener on the Other Side; It’s Also Very Brown over Here. J. Exp. Soc. Psychol. 2013, 49 (6), 1093–1099. https://doi.org/10.1016/j.jesp.2013.07.011.

9. Unsplash. Photo by Erik Mclean on Unsplash. https://unsplash.com/photos/nfoRa6NHTbU (accessed Nov 3, 2020).