Tag Archives: Paris

Love In Paris!

If you know me, you’ll know that one of my favorite films is the French movie, “Amélie” (2001). Set in none other than the charming French village of Montmartre, “Amélie” tells a whimsical story of attraction and love. Once a hub for working-class citizens, Montmartre drew many artists with its liberal reputation. Renowned painters van Gogh, Renoir, and Toulouse-Lautrec were among the many to call the village home (Myers, 2007).

In the film, Amélie works for the Monsieur Collignon at the Café des 2 Moulins, a real location in Montmartre.

I was thrilled to visit the village with a group of my friends. After a few hours exploring, one particular sight remained with me. A gate heavy with love locks — a common sight in the so-called city of love and a symbol of couples’ eternal love. Between the love locks, the cobbled streets, and Le Mur des Je T’aime, my Montmartre, like Amélie’s, spoke of whimsy and love.

Spanning 40 square meters, Le Mur des Je T’aime was created in 2000 and features the phrase “I love you” in 250 different languages. The red fragments represent pieces of a broken heart, and the wall itself represents the capacity for healing through love.

Theories of love have evolved and developed constantly for centuries. Some of us believe in love at first sight. Others, like those who hang their locks upon gates, believe in eternal love. All of us have experienced love in some form or another, whether it be companionate, romantic, or maternal.

One study aiming to answer the question of whether romantic love lasts, observed through functional magnetic resonance imaging (fMRI) that the test subjects, 10 women and 7 men in reported long-term romantic relationships,  exhibited significant brain activity in dopamine-rich areas and areas associated with maternal love when shown images specific to their romantic partners (Acevedo et al., 2012). Responses to long-term partners’ images were measured alongside control images of close friends, familiar acquaintances, and low-familiar acquaintances. Researchers gave participants questionnaires measuring romantic love, obsession, IOS (closeness with one’s partner), friendship-based love, sexual frequency, and relationship length. In short, activation patterns in patients’ brain regions suggested that subjects experienced pleasure when presented with stimuli related to their long-term romantic partners. The ventral tegmental area (VTA), an area of the brain often generally associated with romantic love, showed activation in long-term relationships as well. Interestingly, among activated regions was the posterior hippocampus, an area that seems to activate in response to hunger or cravings (LaBar et al., 2001; Pelchat et al., 2004) — which makes me feel a tiny bit better about my love for ice cream.

While signifiers of romantic love activated dopamine-rich brain areas related to desire, those related to friendship largely activated opiate-rich ones related to pleasure. The study cites a key distinction previously established by researchers Berridge and Robinson, between  “wanting” and “liking,” that positions the two as mutually exclusive. While wanting someone is related to the reward that long-term romantic bonds connote, liking someone is more so an aspect of attachment and pair-bonds. Acevedo and her team wrote that, as a drive, romantic desire is unlike basic emotions in that it is comparatively goal-driven and “hard to control” (Acevedo et al., 2012). They observed that the brains of those in long-term romantic relationships also exhibited significant activity in the opiate- and serotonin-rich areas associated with friendly attachment — activity that is absent from early-stage romance.

Romantic partners attach their locks to this gate in Montmartre to eternalize their love. Love locks are a common sight across Paris.

An article published by Song et al. in 2015 focuses on a similar study that supports the role of romantic love in altering brain architecture, results which align with those of previous fMRI studies (Song et al., 2015). Song et al. acknowledges the work of Acevedo et al. in using fMRI to propose brain regions related and unrelated to romantic love, as well as the work of later researchers (Cacioppo et al., 2012) in dividing these identified regions into those responsible for emotion, reward, and memory, and those responsible for social cues and memory. One weakness of the present study is its longitudinal approach, a model which often resists laboratory control. Song et al. suggest that future research conducted on the topic implement cognitive and behavioral tasks to directly test the hypothesis that love-related alterations of resting brain function reflect an evolutionary drive to select the most fit partner (de Boer et al., 2012). Still, despite its limitations, the study by Song et al. is ultimately valuable because it highlights the function of romantic love.

Ultimately, the study by Acevedo et al. posits that long-term relationships can sustain reward- and value-based brain signals similar to those typically observed during the beginning stages of love, while also fostering the type of “liking” associated with friendly attachment and bonding. In other words, long-term romantic love is possible, and one can love their partner and be their best friend, too.

Of the hundreds and thousands of Parisians and tourists who’ve eternalized their romances on locks upon the fences of Paris, maybe some will succeed. All of us will find love in Paris, whether it be with the city, other people, or life itself. And I can’t wait to find out what comes my way!

 

References

Acevedo BP, Aron A, Fisher HE, Brown LL (2012) Neural correlates of long-term intense romantic love. Social Cognitive and Affective Neuroscience 7:145-159. https://doi.org/10.1093/scan/nsq092.

Cacioppo S, Bianchi-Demicheli F, Frum C, Pfaus JG, Lewis JW (2012) The common neural bases between sexual desire and love: a multilevel kernel density fMRI analysis. The Journal of Sexual Medicine 9:1048-1054. https://doi.org/10.1111/j.1743-6109.2012.02651.x.

de Boer A, Van Buel EM, Ter Horst GJ (2012) Love is more than just a kiss: a neurobiological perspective on love and affection. Neuroscience 201:114-124. https://doi.org/10.1016/j.neuroscience.2011.11.017.

LaBar KS, Gitelman DR, Mesulam MM, Parrish TB (2001). Impact of signal-to-noise on functional MRI of the human amygdala. Neuroreport 12:3461–4.

Myers N (2007) The Lure of Montmartre, 1880–1900. Heilbrunn Timeline of Art History.

Paris Convention and Visitors Bureau (n.d.) Le mur des je t’aime. Paris.

Pelchat ML, Johnson A, Chan R, Valdez J, Ragland JD (2004) Images of desire: food-craving activation during fMRI. Neuroimage 23:1486–93.

Song H, Zou Z, Kou J, Liu Y, Yang L, Zilverstand A, Uquillas Fd,  Zhang X (2015) Love-related changes in the brain: a resting state functional magnetic resonance imaging study. Frontiers in Human Neuroscience. https://doi.org/10.3389/fnhum.2015.00071.

Image 1, Café des 2 Moulins from “Amélie” (2001): Wikimedia Commons.

Images 2-3 were taken by myself.

There’s Nothing Like the Smell of Home

Photo of the metro

About two weeks ago, I arrived very jet-lagged in Paris and couldn’t wait to explore the city. I wanted to take it all in – the sights, the sounds, and the smells. We hit the ground running during our first evening in Paris and rode the metro to the Eiffel Tower. As we waited in the metro station, I realized that I recognized the exact smell of the station. The dusty, metallic smell of the metro brought back many fond and vivid memories during my childhood where I often rode the metro in Toronto. I began to wonder why the smell of the metro brought back such vivid, emotional memories that happened over 10 years ago.

Balls at the museum that emitted smells when you picked them up!

Fast forward to several days ago, I experienced something similar in the Musée du Parfum (perfume museum). It is an amazing museum that is filled with lots of perfume and strong scents that we were able to sniff! One of the scents that stood out to me smelled just like a campfire. Similar to my metro experience, the strong smell of the burning wood brought back many great memories of roasting marshmallows around a bonfire at camp every year.

Fragrant roses at the museum

 

 

In the courses that I’ve taken as an NBB major, I have learned about the separate pathways in the brain that are active during olfaction, memory retrieval, and certain emotional responses. Interestingly, I have not yet learned what happens when those pathways interact like when an emotional memory is retrieved from an odor. I wanted to delve deeper and learn more about what is happening when memories and emotions are retrieved from odors.

Olfactory Pathway Diagram

 

It is already known that olfaction, memory, and emotion are closely linked in the brain. An olfactory signal is transmitted from the primary olfactory cortex to the amygdala and the hippocampus before being sent to higher order olfactory cortices (Shipley and Reyes, 1991). The amygdala is generally associated with emotional responses, while memory processes are closely linked to the hippocampus (Fortin et al., 2004; Cardinal et al., 2002). So, the olfactory signal is relayed through two brain structures that are important for both emotion and memory. 

In 2014, Saive et al. published a study that sought to better understand the interaction between emotion, olfaction, and memory. They tested the hypothesis that emotions invoked by odors facilitate the memory of specific unique events. To do this, they created a model to study memory and mimic real-life situations as best as possible in humans. Participants explored three laboratory episodes, each consisting of three unfamiliar odors (what), positioned at three specific locations (where), within a specific visual environment (which context). Participants explored one episode per day for three days, which they called encoding days. On the 4th day, called retrieval day, they were tested with distractor odors and the odors that they had previously experienced. The distractor odors were used to make sure that participants were associating the correct smells with their memory. Participants were asked to push a button if they recognized the smell, and then had to choose the specific location that they experienced the odor and the correct visual context. They also rated the odors based on pleasantness to investigate the influence of emotion on memory performance.

This study had several important findings that helped researchers better understand what was going on when participants retrieved memories from specific odors. First, they found that the number of accurately remembered contexts and locations was significantly higher when the odors were more pleasant or more unpleasant than neutral. This suggests that the intensity of the emotion  and the distinctness of the smell (but not pleasantness vs. unpleasantness) enhanced memory retrieval. This is what they expected to see – we are more likely to associate a memory that has emotional context with an odor than a neutral smell that we might experience every day.

Measured response times showed that the more information the participants remembered about an episode (what, where, which context), the faster they answered. Interestingly, the time period between odor recognition and retrieving details about their experience was constant no matter how accurate their retrieval was. Since there was no response time difference observed, researchers suggested that after odor recognition participants immediately recalled the whole episode at once rather than in pieces. Put simply, participants didn’t go step-by-step in their memory to recall where there were or how they were feeling, they instead remembered the entire memory at once. This led the researchers to propose a model to explain the cognitive processes that are involved in this unique memory retrieval. This model states that recognizing an odor and retrieving details about the memory associated with the odor are combined into a simultaneous memory retrieval process that begins as soon as an odor is smelled.

One strength of this study is that it mimicked real-life scenarios in the laboratory as naturally as possible by allowing participants to freely explore contexts with unique odors and ranging emotional valences. This makes the model suggested by the researchers more relevant to life outside of the laboratory and helps us better understand how odor is closely tied to memory recognition. Now I understand why I was able to quickly retrieve memories from so long ago just from a smell. Maybe many years from now, the smell of fresh baked bread will bring back fond memories of the many boulangeries (bakeries) I visited during my time in Paris.

Cheers,

Sarah

Bibliography:

Cardinal, R. N., Parkinson, J. A., Hall, J., & Everitt, B. J. (2002). Emotion and motivation: the role of the amygdala, ventral striatum, and prefrontal cortex. Neuroscience & Biobehavioral Reviews26(3), 321-352.

Fortin, N. J., Wright, S. P., & Eichenbaum, H. (2004). Recollection-like memory retrieval in rats is dependent on the hippocampus. Nature431(7005), 188-191.

Saive, A. L., Royet, J. P., Ravel, N., Thévenet, M., Garcia, S., & Plailly, J. (2014). A unique memory process modulated by emotion underpins successful odor recognition and episodic retrieval in humans. Frontiers in behavioral neuroscience8, 1-11.

Shipley, M., & Reyes, P. (1991). Anatomy of the human olfactory bulb and central olfactory pathways. In The human sense of smell (pp. 29-60). Springer Berlin Heidelberg.

Images:

http://www.cbc.ca/news2/interactives/brain/gfx/smell-pathway.jpg – Olfactory pathway diagram

https://pixabay.com/en/train-subway-tunnel-speed-1836126/ – Metro photo, Creative Commons

Photos at the museum – taken by myself

La belle ville de Paris: Perceptions of Beauty

So far, two weeks of getting lost in the metro, enduring drastic weather changes, and having frustrating French conversations at the market have passed during our stay in Paris. From the expectation of having exact change for every monetary transaction to the snarling gazes at our (somewhat) loud group of fifteen in the metro, adapting to the social norms of the French culture has proven to be quite the challenge (I’m just glad I haven’t been pickpocketed…yet).

Arc de Triomphe

However, living in one of the world’s most beautiful cities and being surrounded by some of the most famous landmarks in the world have made it easy to forget these daunting hardships faced by our curious group of American college students. Whether it’s marveling at the size of the Eiffel Tower, walking down the Champs-Élysées with the Arc de Triomphe always in view, or even just observing the characteristically quaint Parisian architecture of all the apartment buildings, Paris always has something to offer around every corner. Thus, as a student who’s on this trip to learn more about neuroscience (and to eat lots of delicious food), I began to question myself: What makes these Parisian scenes so appealing and beautiful? What’s the neuroscience behind what we determine as beautiful? I’m hungry, where can I find me some crêpes?

Eiffel Tower

I came across a study focusing on brain systems with regards to aesthetic and perceptual judgment. The scientists who conducted this study, Ishizu and Zeki (2013), have previously shown that the experience of beauty, regardless of its source (for instance, looking at a famous art masterpiece or listening to beautifully composed music), activates an area of the medial orbitofrontal cortex (mOFC) (Ishizu and Zeki, 2011). This area of our brain is involved in the cognitive process of decision-making. Thus, judgment comes into play when you’re making these decisions.

medial orbitofrontal cortex (mOFC)

If you were shown a picture and you were told to say whether you thought it was beautiful or not, not only are you making judgements based on the picture’s aesthetics, you’re also making judgements based on its quality. So what’s the difference between the two? Let’s say you were given two paintings and you were told to determine which one you thought was more beautiful. When shown these pictures, you see that one painting (let’s say painting A) was three times the size of painting B and also seemed to appear brighter. Right off the bat, you’ve made judgements about painting A’s qualities (size and brightness). However, when you observe painting B, you notice that even though it may not be as big or as bright as painting A, you find painting B’s content to be portrayed as more aesthetically pleasing than painting A. This study aimed to figure out whether aesthetic judgements also involved the activity of the mOFC and how these two types of judgement contribute towards judging the beauty of something, like crêpes!

To test this, human volunteers (non-artists or musicians to alleviate any bias) went through two sessions: aesthetic and brightness. In each of these session, the subjects were shown a series of two paintings and were told to judge which one was more beautiful (in the aesthetic session) or brighter (in the brightness session). The researchers used functional magnetic resonance imaging, or fMRI, scans that acquired readings of blood oxygen levels in the brain. This allows researchers to see what areas of the brain are being activated when the subjects are told to judge the paintings.

Figure 6 of Ishuzu and Zeki (2013) – shows what brain areas are affected by the type of judgment (brightness or aesthetic).

Results showed that aesthetic and brightness judgments use both shared and separate brain systems. While aesthetic judgement mainly activated subcortical regions and the OFC (areas previously mentioned that were associated with beauty), brightness judgement did not activate any areas with significance compared to the areas activated by aesthetic judgment. However, both aesthetic and brightness judgement activated shared systems, mainly involving the dorsolateral prefrontal cortex (dlPFC) (involved with decision making, memory, and cognition) and bilateral anterior insula (known to be involved with many functions, including cognitive and emotional processes).

A beautiful crêpe

This new insight has led me to think about how I judge Paris’s beauty. Do I think the Eiffel Tower is beautiful, or am I just awestruck by its massive size? Do I think the Parisian architecture is beautiful, or is my familiarity to what I normally see in America causing me to think otherwise? The study mentions that further separating the processes of judgement, decision, and experience is difficult because they all use the same brain areas. Being able to understand these separate processes would allow us to really understand how this part of our brain works and finally uncover the truth as to why I find crêpes so beautiful.

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Sources:

Ishizu T, Zeki S (2011) Toward A Brain-Based Theory of Beauty. PLoS ONE 6(7):e21852.

Ishizu T, Zeki S (2013) The brain’s specialized systems for aesthetic and perceptual judgment. The European Journal of Neuroscience 37(9):1413–1420.

mOFC picture: https://commons.wikimedia.org/wiki/File:MRI_of_orbitofrontal_cortex.jpg

Arc de Triomphe, Eiffel Tower, and Crêpe pictures were personally taken.

Making Chocolate like a Pro

Have you ever watched a circus performer juggle for hundreds of people or a master chef expertly flip an omelet? Have you ever seen an elegant display of technique that takes some people years to master and thought to yourself: “yeah I think I can do that”? Well maybe you haven’t, but last week during our visit to the Musée de Chocolat, I had this experience.

Ok maybe not that exact thought process. In truth, when the master chocolatier asked the group: “ok who wants to try,” it was more along the lines of: “yeah, let’s see what happens.” As I took the triangles in my hands I really had no idea what I was doing, but after a small point of clarification, my hands started mixing the chocolate exactly how I had seen him do it. In fact it was going so well that he turned to me and asked: “have you done this before?” To which my reply was simply: “nope.”

Blog 2.1

Blog 2.2

The workshop continued in much the same manner where he would show us how to do a step in the chocolate making and I would reenact exactly what I had seen. Afterward I started wondering how a motion so complex could come so naturally to me.

A recent study has analyzed the role of the action observation network (AON), a network of sensorimotor regions in the brain, in the presence of familiar and unfamiliar actions (Gardner et al., 2015). The researchers asked the participants to watch a short video of dance moves and at the end of it, were asked to pick which of two options should follow in the sequence. The control group was asked to follow the dot sequence that was displayed on the same videos and afterwards had to choose which color was the last one pictured. For the duration of the test, participants were in an fMRI machine so that the investigators could record their brain activity. After the testing and recording, the participants rated the familiarity of the actions in the videos.

When Gardner and his colleagues examined the brain scans of each participant group, they found that the action-focused group showed greater activation in their motor cortices than the dot-focused group. Additionally, the more familiar tasks resulted in increased activity in the AON. The researchers then tested for the connectivity between the inferior parietal lobule (IPL), the middle temporal gyrus (MPG), and the inferior frontal gyrus (IFG) and from these tests developed a working model of how this system works in the presence of familiar motion stimuli.

Blog pic

The IFG and MTG receive input from the movement stimulus and relay this information back to the IPL. The connections between these three regions can also be modified by familiarity by a currently unknown pathway.

Now let’s return to my example of chocolate making (mmm… chocolate…). When I watched the professional chocolatier scraping the chocolate around the marble, the movement triggered the AON in my brain. Even though I had never performed this particular action, I have had many years of experience cooking and it is likely that this somehow contributed to the “familiarity modulation” the study discusses ultimately allowing me to make delicious chocolate with my friends.

blog map

-Kamin Bouguyon

References:

Gardner, T., Goulden, N. & Cross, E.S. (2015) Dynamic Modulation of the Action Observation Network by Movement Familiarity. The Journal of Neuroscience, 35, 1561-1572.

Confessions of a Chocoholic

Looking back on the past couple weeks, I can definitely confirm that this trip has been one of gustatory indulgence. Surrounded by dazzling array of markets and boulangeries, I quickly abandoned my gluten-free/organic/veggie-based diet in exchange for a month-long foray into the hedonistic world of carbohydrates and simple sugars. The biggest change, however, came in the form of massive increases in the amount of chocolate I consumed on a daily basis. For a self-acknowledged Chocoholic, Paris exists simultaneously as the “worst” (and best) place to live. Being vegan, I was ecstatic to discover a vast array of artisan, naturally dairy-free creations present at every Chocolatier I visited. From velvety ganache to decadent truffles, with every bite I fell deeper under a magical, cocoa-fueled spell.

chocolate

SO BEAUTIFUL.

However, even as “Viva la Chocolate” became my new mentality, I wondered how the habitual inclusion of this high-sugar, high-fat product would affect my short and long-term health. When I return stateside, should I include less chocolate in my diet…. or avoid it all together? How much is “too much” when it comes to such an addictive dessert?

To investigate these questions, I turned to a recent study by Kwok et al. that examined the association between chocolate intake and future cardiovascular events. Based on long term data collected in the EPIC-Norfolk population study from a total of 20,591 European men and women, the cumulative meta-results of the study actually suggest that a higher chocolate intake is associated with a lower risk of coronary heart disease, stroke, and cardiovascular disease. Wait…. what?! So my consumption of chocolate may actually be helping me, rather than hurting me? Not convinced, I looked to other research to confirm these results.

My FAVORITE place.

My FAVORITE place.

Immediately, I found a fascinating study by Massee et al. examining the short and long term effects of cocoa supplementation on mood and mental fatigue, cognitive performance and cardiovascular functioning in young adults. To make a key distinction, cacao is the raw seeds obtained from the Theobrama cacao tree, cocoa is the roasted, grounded product, and chocolate is the processed confectionary dessert with added sugars and fats (Latif, 2013). Cacao seeds have been used as medicine for centuries and are rich in with catechin and epicatechin antioxidants known as “flavanols” (Nehlig, 2013). Based on previous animal studies, the researchers’ hypothesized that cocoa flavanols may have the ability to act on the human brain and improve cognitive performance through direct enhancement of memory systems (Nehlig, 2013). Furthermore, cocoa flavanals could potentially improve cardiovascular health by regulating blood pressure and cerebral blood flow (Dinges,2006).

In the experiment, the researchers’ investigated the effects of cocoa supplementation in 40 healthy young adults using a placebo-controlled, double blind test over a four-week period. Participants were randomly assigned to receive either an active cocoa tablet containing 250mg cacao seed extract OR an identical placebo tablet containing only cellulose powder. The researchers’ examined both the baseline vs acute (before and 2 hours after the tablets were ingested) and baseline vs chronic effects (4 weeks of daily tablet ingestion). To assess cognitive performance, the participants completed eight computer-based tasks including reaction/decision time, inhibition, and recognition/spatial/contextual memory. To measure mood and mental fatigue, the participants completed the mentally fatiguing cognitive demand battery test (CBD) which requires completion of two serial subtraction tests, a rapid visual information processing task (RVIP) and a visual cognitive fatigue scale. To assess cardiovascular health, the researchers’ measured the participant’s blood pressure and cerebral blood flow. The participants completed a total of three testing sessions: baseline (before ingestion), acute (2-3.5 hours after tablet ingestion) and sub-chronic (4 weeks after initial testing).

Cocoa cocoa everywhere!

Cocoa cocoa everywhere!

At the acute time point, cocoa-supplemented participants reported feeling significantly less mentally fatigued prior to completing the cognitive demand battery test and showed improved performance on the subtraction component of the CDB compared to the placebo group. Therefore, the researchers’ concluded that 250 mg dose of cocoa flavanols was found to improve mental fatigue and minor aspects of cognitive performance acutely, but not sub-chronically (aka long term) during a highly demanding task.

However, in both the short and long term measures, the study failed to produce any evidence that cocoa increases performance in the SUCCAB tests or enhances cardiovascular function. These results could have been affected by the study’s small size, 30 day experiment course, or insufficient dosage. In the future, I would be interested to see if these same effects could be mirrored in older adults and with different amounts of cocoa used.

Though still a skeptic at heart, based on the findings from these two studies, perhaps my addiction to chocolate isn’t as bad as I initially thought. In fact, if consumed in moderation (working on that one), chocolate may actually benefit some aspects of my mental and physical health. With that in mind, I’ll feel a little less guilty every time I gobble down another praline I made in Choco Story. After all, it’s the smart thing to do right?

References:

Dinges DF (2006) Cocoa flavanols, cerebral blood flow, cognition, and health: going forward. J Cardiovasc Pharmacol. 47Suppl 2 ():S221-3.

Kwok CS, Boekholdt SM, Lentjes MA, Yoke YK, Ruben RN, Yeong JK, Wareham NJ, Myint PK, Khaw KT (2015) Habitual chocolate consumption and risk of cardiovascular disease among healthy men and women. Heart. 2014-307050

Latif R (2013) Chocolate/cocoa and human health: a review. Neth J Med.71 (2):63-8.

Massee LA, Reid K, Pase M, Travica N, Yoganathan J, Scholey A, Macpherson H, Kennedy G, Sali A, Pipingas A (2015) The acute and sub-chronic effects of cocoa flavanols on mood, cognitive and cardiovascular health in young healthy adults: a randomized, controlled trial. Front Pharmacol. 6:93.

Nehlig A (2013) The neuroprotective effects of cocoa flavanol and its influence on cognitive performance.Br J Clin Pharmacol. 75(3):716-27

Young Oliver “Sponge Bob ‘Did You Say Chocolate.’” Online Video Clip. Youtube. Youtube 16 May 2010. Web. 20 June 2016.

Images:

www.agriculturewire.com

Don’t be fooled by those tasty looking cakes.

Dear friends,

With this week marking the end of my time studying abroad, I look back on all that I’ve experienced and know that I will truly miss being in Paris. Maybe it’s the people I’ve meet, or the sights I’ve seen, or just all the amazing food I’ve had, but I really can’t put my finger on why I’ll miss this place.

Amazing falafel from L'as du Fallafel

Amazing falafel from L’as du Fallafel (definitely beats Falafel King)

Speaking of food, I’ve gotten into the habit of trying a different pastry at lunch each day! While definitely not a healthy practice that I should keep up when back at home, I’ve gotten to taste some really good sweets!

Because of my minimal French speaking skills, I choose my pastries simply by pointing to one at random. This technique works fairly well for the most part because I usually end up with a delicious pastry in my stomach! However, the other week at Blé Sucré, I chose one that tasted awful. I think I got a rum cake, but I honestly can’t be too sure since I didn’t bother to read the description (I probably wouldn’t have understood it anyways). Interestingly, while I thought it was absolutely atrocious and extremely bitter, others thought it didn’t taste that bad. At the time, I couldn’t understand why they thought it tasted any good, so I decided to do some research.

Location of Blé Sucré in relation to ACCENT Center

Location of Blé Sucré in relation to ACCENT Center

Surprisingly, a great amount of information exists on individual differences in food preferences. In a recent study conducted with 305 participants, the researchers concluded that genetics play a large role in bitter food taste preference (Negri et al., 2012). In this study, the researchers collected a sample of each participant’s saliva to determine their genetic code for the TAS2R38 gene, a DNA sequence responsible for creating a specific bitter receptor that recognizes a chemical called 6-propyl-2-tiouracil (PROP). The DNA sequence of this gene can vary to cause an individual to be considered as a non-taster, medium taster, or super taster. Basically, an individual could not taste the bitterness of PROP, could taste the bitterness, or could taste the bitterness and thought it was extremely disgusting.

Molecular structure of PROP

Molecular structure of PROP

After the DNA genotyping, the researchers gave the participants a small amount of PROP to taste and asked them to rank the amount of bitterness that they experienced on a scale of 1 (no taste) to 4 (very unpleasant). The participants then answered a questionnaire about the specific foods that they ate in the past three days. The researchers instructed them to focus on any bitter vegetables they consumed. With some statistical analysis tests, Negri et al. found that individuals with increased PROP sensitivity tend to avoid bitter foods and therefore have a lower consumption of these types of food in their daily routine. Applying this conclusion to my situation, I guess this means that I’m a supertaster! I’m not sure if this difference in preference has any other implications, but I think that would be a great next experiment to look into!

Are you a super taster?

Are you a super taster?

This study definitely helped clear my confusion about how my friends could possibly think that my rum cake tasted any good, however, I did find that it contained a couple weaknesses. Negri et al. recruited their participants through convenience sampling, where they asked people in their clinic or in a nearby university if they wanted to participate, instead of conducting a random sample. Using this type of sampling method may lead to an unrepresentative sample of the population and therefore yield results that may not be applicable to their population of interest. Additionally, I personally find it difficult to recall everything I ate in the last three days, so I believe that the participants may have found it difficult too. This problem may result in a response bias that could impact the integrity of the results as the participants could have just listed down some of the foods that the researchers included in the questionnaire instead of actually trying to remember what they ate. Despite these shortcomings, this study uses good experimental controls and provides an excellent explanation of their methods to the point where I could most likely replicate their experiments!

Array of delectable goods sold at Blé Sucré

Array of delectable goods sold at Blé Sucré

While I doubt I would spend the rest of my time in Paris trying to reproduce this study, I have learned a valuable lesson: when in Paris, don’t be fooled by those tasty looking cakes.

Best,
Phi

 

References

Negri R, Di Feola M, Di Domenico S, Scala MG, Artesi G, Valente S, Smarrazzo A, Turco F, Morini G, Greco L (2012) Taste perception and food choices. Journal of pediatric gastroenterology and nutrition 54:624-629.

Twenty-one and trying to keep it sober

To an American, turning twenty-one means more than adding a hyphen to your age. On June 8th, I got a call from my parents back in Rhode Island not only to wish me a happy birthday but also to pass along several warnings about what everyone associates with a twenty-first birthday: alcohol.  “We trust you,” they said, “but make good decisions!”

Cake 2IMG_1870

IMG_1993

My birthday week, however, played out nothing like my parent’s expected.  I received three fantastic birthday cakes and dozens of birthday wishes, visited the beautiful town of Blois, France and the Versailles castle, and witnessed an unbelievable circus performance at Le Folies Bergere. Alcohol didn’t interest me, and for a moment I thought my parent’s advice about alcohol didn’t apply to me this trip.  After our group took an excursion to Le Musee Gourmand du Chocolat, a chocolate museum complete with a chocolate workshop and demonstration, I realized that I should have applied my parent’s advice  applied to my chocolate eating habits, not my first glass of wine. If I eat more than a few Hershey’s Kisses worth of chocolate I experience symptoms like coughing, temporary tightening of the throat, migraines, dizziness, and light-headedness.  Over the years, I learned to live with this food sensitivity, and yet, finding myself surrounded by chocolate during the excursion did nothing to curb my cravings.  As I usually do when offered chocolate, I ate far over my limit and dealt with my pounding head at the end of the visit.

 

I may have a chocolate problem–I might go as far as calling myself a chocoholic–but I’m not alone.  Chocolate is one of the most craved foods in the United States (Heatherington and Macdiarmid, 1993).  Although studies with dark chocolate suggests it can lower blood pressure (Ried et al., 2010), over-consumption of it can lead to health deficits like weight gain, or in my case, headaches and sore throats.

 

A: Blois, France B: Versailles, France C/D: The Chocolate Museum and circus within Paris

A: Blois, France
B: Versailles, France
C/D: The Chocolate Museum and the Kermezzoo circus within Paris

A study by Kemps et al. in 2012 offers a way to curb chocolate cravings through our sense of smell.  In their experiment, they asked 67 female undergraduates between the ages of 18-35 to look at 30 images of 10 different kinds of chocolate food such as cakes, bars, and ice cream.  Each image was shown for 5 seconds with a delay after the image.  During the delay, participants continued to imagine the image they saw in an attempt to produce a cravings for it (Kemps et al., 2005).  During the delay, the participant also smelled a bottle with the scent of water (the control), jasmine (a non-food smell), or green apple (a food smell), then rated their desire for chocolate.  The data collected showed that when participants smelled jasmine, their desire for chocolate was at its lowest.

The teal area shows the cingulate cortex, activated by chocolate consumption during the experiment by Small et al. in 2001.

This study was the first of its kind to link non-food odors as a useful means of suppressing chocolate cravings, but what happened in the brains of these participants?  Another study by Small et al. in 2001 analyzed the brain’s motivation to eat chocolate and found that the anterior cingulate cortex in the brain starts to becomes active when you take that first bite of chocolate and stays active even when you’ve eaten enough chocolate that it becomes averse.  A different study by Small et al. in 1997 showed that stimulating both our taste and smell sensations activates limbic brain areas, which include the cingulate cortex mentioned above.

Some of many brain areas associated with chocolate eating, smelling, and motivation.

Some of many brain areas associated with chocolate eating, smelling, and motivation.

 

With these two studies in mind, how does all of this fit into the chocolate craving antidote discovered by Kemps et al.?  If together smell and taste can activate the cingulate cortex and the anterior portion of the cingulate cortex is involved with our motivation to eat chocolate, then smelling a non-food smell like jasmine may be blocking something along that processing pathway between chocolate consumption and our motivation to each chocolate in the cingulate cortex.

 

Of course, this is just my own speculation.  Kemps et al. did not go into further detail about why jasmine effect on the brain our desire to eat chocolate, if jasmine is the only odor with this effect on chocolate cravings, or if jasmine an suppress cravings for other foods.  The study also focused on only one age group and one sex, therefore its results may not seem significant this field until other researchers conduct follow up research.  Regardless, this still an intriguing study in how it offers a potential therapeutic for women who have problematic chocolate cravings or other eating disorders.  Not only that, but maybe it could help people like me who simply don’t want to give up eating something that tastes so wonderful.

-Nicole Asante

Resources:

Kemps E, Tiggemann M, Bettany S (2012). Non-food odorants reduce chocolate cravings, Appetite 58(3):1087-1090.

Ried K, Sullivan T, Fakler P, Frank O, Stocks N (2010). Does chocolate reduce blood pressure? A meta-analysis, BMC Medicine 8(39).

D Small, Zatorre R, Dagher A, Evans A, Jones-Gotman M (2001). Changes in brain activity related to eating chocolate: From pleasure to aversion, Brain 124:1720-1733.

Small D, Jones-Gotman M, Zatorre R, Petrides M, Evans A (1997). Flavor processing, NeuroReport 8 (18):3913-3917.

http://bethycotter.wdfiles.com/local–files/cingulate-cortex/Screen%20Shot%202012-10-26%20at%202.31.57%20AM.png

 

Café au Lait to get Through the Day

My amazing “café au lait” from Coutume Café in the 7ème arrondissement

 

Who doesn’t love a nice, hot cup of coffee after a morning shower? Not only does it taste AMAZING, but it also wakes you up and gets you ready for the day to come. Every morning, for the last 4 or so years, I drink a cup of coffee while getting dressed or eating breakfast. So, upon coming to Paris, I undoubtedly continued my ritual.

The walk from Cité Universitaire (where I live) to Coutume Café (my favorite coffee shop).

 

 

 

I essentially used my love of coffee as an excuse to visit as many cafés and small restaurants as possible. However, I soon discovered the enormous difference between French coffee and the American coffee that I am used to. The French are huge advocates for espresso, that is, a coffee-like drink served in tiny porcelain cups. However, unlike American coffee, espresso is extremely potent and filled with a TON of caffeine. Over the past few weeks, I too have become a lover of espresso and the large amount of caffeine and “energy” that comes with it. However, I was not quite sure exactly how caffeine affects the brain resulting in what we perceive as a boost in energy and decrease in drowsiness. So, throughout my days in Paris, I looked for an answer.

Typical French coffee (left) vs. typical American coffee (right)

While searching for an answer, I stumbled upon an article by Lazarus et al. (2011) concerning the effects of caffeine on wakefulness. Previous research found that caffeine counteracts fatigue by binding to adenosine A2A receptors. Adenosine, an inhibitory neuromodulator, has been linked to regulation of the homeostatic sleep drive. So, by binding to the receptor in the brain that normally binds to adenosine, caffeine indirectly prevents adenosine from functioning properly, altering one’s sleep pattern (Huang et al., 2011). Lazarus et al. used this information to construct their experimentations.

In their study, Lazarus et al. bred a strain of rats that had a knockout of the A2A receptor in their nucleus accumbens, that is, these rats did not have this receptor within this specific brain region. They then performed EEG (electrical monitoring) tests on these rats and compared their electrical brain activity with that of control rats (rats that did not have the A2A knockout). The researchers administered equivalent concentrations of caffeine to both groups of rats and monitored their brain’s electrical activity during sleep cycles. What they found was extremely interesting. The caffeine caused increased wakefulness in the control rats (those that did not have the A2A receptor knockout), while caffeine had no effect on wakefulness in the experimental rats (those with the A2A receptor knockout). This means caffeine not only blocks adenosine from binding to the A2A receptor (Huang et al., 2011), but it also prevents the activation of the “adenosine break,” resulting in increased wakefulness.

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A figure from Lazarus et al. (2011) depicting the adenosine A2A receptors in the nucleus accumbens of rat models. The left shows a control (wild-type) rat nucleus accumbens, while the right shows an experimental (knockout) rat nucleus accumbens.

Furthermore, the data from this study suggests that caffeine induces arousal and wakefulness by activating pathways in the nucleus accumbens that have formerly been associated with locomotion and motivational behaviors. This is a novel finding because it implicates caffeine in more than just the blocking of adenosine, but also in the activation of further neuronal circuitry, promoting a sense of “energy”.

A figure from Lazarus et al. showing the effect of caffeine on wakefulness. There is no significant increase in wakefulness in the A2A receptor knockout mice as more caffeine is administered. However, there is a significant increase in the wakefulness of wild-type mice as more caffeine is administered.

What I find super interesting about this study is how the researchers localized the antagonist effects of caffeine to the nucleus accumbems. In previous neuroscience classes, I learned of the association between the nucleus accumbens and cognitive processes such as motivation, pleasure and reward, thus implicating this brain region in numerous forms of addiction. With this in mind, I wish the experimenters had monitored the changes in behavior between the experimental and control rats when receiving differing levels of caffeine. This could be accomplished by using an intravenous self-administration task (IVSA). IVSA entails using chambers with small levers that, when pushed, cause specific drugs to be administered into the tail of that rat that pushed the lever (Figure 1). The researchers could perform IVSA for both control and experimental rats, and use either a saline or a caffeine solution as the respective drug. If this was done properly, I predict the control rats to show increased pushing of the lever when receiving caffeine compared to saline, corresponding to an greater feeling of pleasure and reward associated with the caffeine. Alternatively, I predict the experimental rats to show no significant difference in pushing of the lever between administrations of caffeine and saline because the caffeine does not affect their nucleus accumbens in the same way that it does for the control rats.

A very simplified version of the IVSA task in rat models.

 

Regardless, I find the study by Lazarus et al. to be extremely fascinating because, as a regular coffee drinker, it gives me insight to what is occurring in my brain!

Anyway, I’m about to go grab a coffee and walk around the city. Until next time!

~ Ethan Siegel

 

References:

Huang ZL, Urade Y, Hayaishi O (2011) The role of adenosine in the regulation of sleep. Curr Top Med Chem 11:1047–1057.

Lazarus M, Shen H-Y, Cherasse Y, Qu W-M, Huang Z-L, Bass C, Winsky-Sommerer R, Semba K, Fredholm B, Boison D, Hayaishi O, Urade Y, Chen J-F (2011) Arousal effect of caffeine depends on adenosine A2A receptors in the shell of the nucleus accumbens. The Journal of Neuroscience 31(27): 10067-10075

The chocolate adventures of a chocolatier’s daughter in Paris

Chocolate. Chocolate. Chocolate. I can’t even begin to describe how much I love it. To give you guys a bit of context on my never-ending craving, my mom started a chocolate company while I was growing up. On a daily basis, my whole house smelt of freshly rolled truffles, baked brownies and chocolate cookies. Now, everywhere I go, I need to make sure that I have chocolate available at all times.   In my Parisian dorm room, I have at least five chocolate bars in stock. The satisfactory feeling of biting into a creamy piece mid-essay is unbeatable.

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Map of some of the best boulangeries in Paris

Walking around Paris, I love to stop at boulangeries and try whatever they have to offer, chocolate style. Some of my favorites so far include pain au chocolat, opera cake, and chocolate crepes. I recently spent the afternoon vising my brother and his wife in Belgium, and was in chocolate heaven. The Belgian chocolate brownie I had was life changing. My chocolate adventures continued this past Friday when I went to Le Musée Gourmand du Chocolat in Paris. It was quite the delicious experience; I indulged in cinnamon hot chocolate, praline, and other rare chocolates from all over the world. Best afternoon yet.

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Me at Le Musée Gourmand du Chocolat

My current neuroscience mindset made me start to wonder how my chocolate cravings translate to brain activity. In a study by Frankort et al. the researchers studied the short-term effects of chocolate cravings on behavior, specifically how neuroimaging can predict chocolate consumption. The two different experimental groups consisted of participants who smelt chocolate and participants who didn’t, with 17 females in each group. They compared self-reported craving to brain activation showed by fMRI scans which measures the change in blood flow in different brain areas. Previous studies have found that prolonged chocolate exposure, like the chocolate scent group, leads to a decrease in craving. This effect was not observed in the Frankort et al. study; perhaps because the fMRI scan interrupted the 1-hour scent exposure sessions, which displays a weakness of the study since the interruptions don’t accurately model a real life situation.

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Brain activation in areas correlated with chocolate intake. Green: whole group anterior PFC activation, Yellow: exposed group caudate and frontopolar cortex activation, Purple: control group dorsolateral PFC and mid-dorsolateral PFC reduced activation.

Primarily, Frankort et al. found that neural activation in the right caudate and the left lateral frontopolar cortex predicted chocolate intake in the exposure group. The left lateral frontopolar cortex and the right caudate are both associated with reward and memory (Pochon et al. 2002), which explains the chocolate consumption. Furthermore, the left dorsolateral and mid-dorsolateral prefrontal cortex (PFC) correlated negatively with consumption in the control group, meaning the activation predicted decreased intake. These findings make sense since this area is associated with cognitive control (I would guess that I don’t have a very active left and mid-dorsolateral PFC when it comes to chocolate consumption). In both groups, the right anterior PFC, activation was associated with chocolate intake. This region is associated with cognitive behavior, planning and decision making (Wikipedia).

These regions of activation represent a better measure of future chocolate intake than self-reported craving, meaning that my brain knows I’m going to crave chocolate better than I am consciously aware of! The most surprising fact from this study was that overall self-reported chocolate craving did not correlate with intake. Meaning, just because I think I crave chocolate doesn’t mean I necessarily crave it. To really know if I crave something I would have to check my brain scans! A significant weakness of this study was how craving was measured by asking participants one question. Future studies should include a more appropriate measure of craving with multiple questions, since just having one may not fully explain the results.

This newfound knowledge on self reported craving has definitely made me rethink my chocolate consumption. Is a craving really a craving without brain activation? Whatever the answer to this question, I’m going to eat all the chocolate I can in this last week! Maybe I should rename the program title to Neuroscience, Chocolate and Paris.

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Me eating un pain au chocolat

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Me eating a chocolate cake

 

 

 

 

 

 

 

 

-Sasha

References:

Frankort A, Roefs A, Siep N, Roebroeck A, Havermans R, Jansen A. (2015) Neural predictors of chocolate intake following chocolate exposure. Appetite. 87:98-107

Pochon JB, Levy R, Fossati P, Lehericy S, Poline JB, Pillon B, Le Bihan D, Dubois B (2002) The neural system that bridges reward and cognition in humans. An fMRI study. Proceedings of the National Academy of Sciences of the United States of America. 99: 5669–5674

Map: http://www.quora.com/What-are-the-best-boulangeries-and-patisseries-in-Paris-for-each-arrondissement

https://en.wikipedia.org/wiki/Prefrontal_cortex

Walking through Paris

Amongst the many changes I have experienced while in Paris, I noticed that I am walking considerably more than I usually do. While most people are aware of the positive impact walking and exercise can have on the body, I am dedicating this post to exploring the effects of exercise on the brain.

Thanks to my handy Fitbit (yes, I know I am a little obsessed), I am able to track my daily activity, so I have a very good idea about how much exercise I am getting. Between going to class, touring museums, and exploring getting lost in the streets of Paris, I am walking an average of over 8 miles every day. Paris is a very “walk-able” city, and my friends and I regularly opt to walk to our destinations instead of using the metro. I know that this must be affecting my cognitive ability, because even while operating on 4-6 hours of sleep every night, I am able to focus and work surprisingly well.

Fitbit evidence that 1) I am walking crazy amounts in Paris, and 2) I can justify eating multiple pastries a day*  *point 2 has not been scientifically proven

Fitbit evidence that 1) I am walking crazy amounts in Paris 2) I can justify eating multiple pastries a day*
*point 2 has not been scientifically proven

A recent study in college-aged females found that after only a single session of moderate exercise, participants showed increased brain activation during a working memory task (Li et al. 2014). Working memory is a limited brain resource that temporarily stores, processes and updates action-related thinking. It is utilized when you need to actively handle information, and your working memory capacity is an important measure of cognitive function. The researchers in this study used a modified N-back task to measure working memory. This task requires participants to attend to a sequence of stimuli, and determine if the current stimulus matches a stimulus that was “N” steps earlier in the sequence. The task gets more and more difficult as N increases, because it becomes harder to keep track of when a stimulus appeared.

A visual representation of the N-back task used in the study by Li et al. (2014)

A visual representation of the N-back task used in the study by Li et al. (2014)

To compare brain function, the subjects performed this task while in a functional magnetic resonance imaging (fMRI) machine, once following exercise, and once following a rest period. The fMRI measures blood oxygenation, which provides a visual image of brain activation. While there was no significant change in subject performance on the task, the data show more brain activation in the exercise condition, especially in the prefrontal cortex (PFC) and medial occipital cortex during the 2-back condition. The PFC is well recognized to be important for working memory, and the specific areas of the occipital lobe that changed are also involved in online processing. The lack of performance change limits the conclusions that can be drawn from this study, but it is reasonable for me to assume that my working memory capacity is positively influenced by the increased exercise I get in Paris. The researchers clearly showed that exercise influenced the brain areas important for working memory in subjects of my same age and sex, and this effect would likely be enhanced by an extended exercise routine like mine. A future study could explore the effect of chronic exercise, or use multiple behavioral measures to see if that leads to more pronounced changes in working memory performance.

Working memory is not the only brain function influenced by exercise. In fact, hundreds of studies explore how exercise can change the brain. One of the most common focus areas is how exercise increases brain-derived neurotropic factor (BDNF) in the hippocampus. BDNF is very important for brain plasticity, and the hippocampus is highly involved in learning and memory. One study found that exercise enhanced memory and cognition in rats, through the action of BDNF and the pathways it influences (Vaynman, et al. 2004). A different study focused on the non-neuronal cells in the brain, called glial cells (Brockett, et al. 2015). They found that running influenced synaptic plasticity in rats, producing widespread positive effects in both neurons and glial cells in areas associated with cognitive improvement. The last study looked at showed how exercise can help people’s mental health by reducing the stress hormone cortisol, through overall regulation of the hypothalamic-pituitary (HPA) axis (Zschucke et al. 2015).

I walked almost 10 miles before stumbling upon this set at Fete de la musique, and the journey was as fun as the event!

I walked almost 10 miles before stumbling upon this set at Fete de la musique, and the journey was as fun as the event!

It is so interesting to hypothesize about the different ways that my brain may be changing in response to something as simple as walking. Evidence suggests that my working memory capacity, brain plasticity, and mental health are all influenced by exercise. Now that I only have one week left to enjoy Paris, I will make sure to walk everywhere to experience, learn and improve my brain as much as possible. With all of the positive effects Paris seems to have, I know I will be planning a return trip the second I get home!

 

References 

Brockett AT, LaMarca EA, Gould E (2015). Physical Exercise Enhances Cognitive Flexibility as Well as Astrocytic and Synaptic Markers in the Medial Prefrontal Cortex. PLoS ONE. 10(5): e0124859.

Li L, Men W-W, Chang Y-K, Fan M-X, Ji L, & Wei GX, (2014). Acute Aerobic Exercise Increases Cortical Activity during Working Memory: A Functional MRI Study in Female College Students. PLoS ONE. 9(6): e99222.

Vaynman S, Ying Z, and Gomez-Pinilla F, (2004). Hippocampal BDNF mediates the efficacy of exercise on synaptic plasticity and cognition. European Journal of Neuroscience. 20: 2580–2590.

Zschyke E, Renneberg B, Dimeo F, Wüstenberg T, & Ströhle A (2015). The stress-buffering effect of acute exercise: Evidence for HPA axis negative feedback. Psychoneuroendocrinology. 51: 414-425.