Tag Archives: chocolate

How many Ph.D.’s does it take to make Chocolate?

If you ever want to see students and professors alike act like children, take them to a chocolate factory. When we went to the Chocolate Museum last week, I could not contain myself. I started jumping up and down for a solid ten minutes and could not hide away my huge smile. I ate bits and pieces of chocolate that fell into our table until my stomach hurt. And I made everyone laugh when I spilled chocolate on myself.

Ecstatic in my chocolate fantasy.

We got a demo on how to prepare milk chocolate. Milk chocolate requires a colder temperature than dark chocolate (closer to room temperature). So we had to pour the chocolate unto the table and move it around with two spatulas. The Chocolate Museum speaker’s quick moves reminded me of an artist painting fast yet ever precise brushstrokes.

 

chocolate demo

 

I remembered reading an earlier year’s blog post on chocolate (Bouguyon, 2015) before coming to Paris, so as I saw the demo, I knew that moving chocolate around was harder than it seemed. Hence why I was not surprised when some of my classmates struggled to move the chocolate around fast enough. I was quite surprised (and quite amused), however, at how much Dr. Frenzel and Rachel struggled at. I thought that all that pipetting and fine movements done in experiments were going to help, but it seemed like two Ph.D.’s could not keep up with the chocolate maker!

Chaos happens when you take these two out of the classroom.

The presenter’s directions caught my eye, as he said “scrape the smaller spatula on the bigger one.” So what separated his movements from the rest of ours? I hypothesized it had something to do with not only his years of experience, but also at how he looked at the task itself. He differentiated his hand movements on the basis of the size of the tool each hand held….

And that is how I ran into a study titled “Object Properties and Cognitive Load in the Formation of Associative Memory during Precision Lifting” that looks at how the size of an object and our memory of its previous use influences how we lift it up (Li et al., 2009).

In this study, researchers studied how we associate how an object looks (its size or color) to how much it weighs. Associative memory is “the ability to learn and remember the relationship between two unrelated items” (Suzuki, 2015). So we form associative memories when we learn to associate a small spoon as relatively lightweight, for example.

Researchers assigned 40 volunteers to one of four groups: color cue single task (CCS), color cue dual task (CCD), no cue (NC), or size cue (SC). Cue here implies that after a few trials, you will learn to associate an object’s feature (color, size, or neither) with its weight. In the color cue dual task, apart from associating the color of an object with its weight, participants also performed a memory task between lifting objects.

Participants had to lift three objects that weighed either 580 or 280 grams and were either green or blue colored. Two objects had the same size but different weights (580 or 280 grams), while two of the same objects had a different size but same color.

Objects had to be lifted with three fingers (thumb, index, and middle finger), since that way objects are all grasped at around the same angle (2.3 Task). There was a sensor inside each object that measured the force (horizontal and vertical, in Newtons) and acceleration (m/s) at which each object was picked up (2.2 Apparatus).

Figure 1 (Li et al., 2009). Diagram of the objects and force measurement device used.

 

Participants heard a tone to indicate they had to lift the object as fast as they could. Four seconds later, they had to put the object back down. Each participant completed 2 trials (color, size, or no cue lifts) of 18 times each (36 total).

To study how much force the participants estimated they needed to lift each object, researchers calculated how much force was exerted during the first 70 ms of an objected being lifted. Since it is so early in the process of lifting an object, this short timespan tells researchers more about how much force participants though they needed. For example, has it ever happened to you that you imagine an object is heavier than it actually is? So at first you do an awkward movement where you exert more force than you actually need to (take that to be the first 70ms researchers are analyzing). Quite quickly though, you realize that the object isn’t as heavy as you first thought and exert less force than you did during those first milliseconds (hence why researchers did not look at how much force participants exerted overall or later on during those 4s).

Figure 5 (Li et al., 2009). Y-axis (label not provided) measures average grip force (N).

Researchers found that participants relied the most on size to estimate how much force to use when lifting an object with unknown weight (Fig. 5). Put another way, they showed the most difference in how much force they used when picking up objects of different sizes. Results also showed that participants learned to associate, to a lesser extent, an object’s color with its weight (Figure 5).

So this study suggests that our lovely Ph.D.’s can someday also succeed at mixing chocolate just as well as the museum speaker could. All they might need could be some more practice, so they too can learn to associate how much force they should use when using the small and big spatula.

And just to make you jealous, I will let you know that I am writing this while having the best hot chocolate in all of Paris at Café de Flore. If you come to Paris, do not leave without trying it!

Truly a must-have in Paris!

 

References

Bouguyon, K. (2015). Making Chocolate like a Pro | NBB in Paris. Retrieved June 26, 2017, from https://scholarblogs.emory.edu/nbbparis/2015/06/22/making-chocolate-like-a-pro/

Li, Y., Randerath, J., Bauer, H., Marquardt, C., Goldenberg, G., & Hermsd?rfer, J. (2009). Object properties and cognitive load in the formation of associative memory during precision lifting. Behavioural Brain Research, 196(1), 123–130. https://doi.org/10.1016/j.bbr.2008.07.031

Suzuki, W. (2015). Associative Learning and the Hippocampus. Retrieved June 26, 2017, from http://www.apa.org/science/about/psa/2005/02/suzuki.aspx

Pictures taken by writer, with consent of persons depicted. June 2017.

Our Brains Want Chocolate…Literally

Salut mes amis!

I have literally been waiting since the beginning of this trip for this one day. I’ll give you some clues: It’s sweet. It’s yummy. There’s a golden ticket involved. Do you know it yet? Willy Wonka’s chocolate factory!!!! Okay maybe not that exact one, but I’d say this comes as a close second. Just walking in immersed me in an air of chocolatey yumminess, and this was just the entrance with the gift shop. The excitement was literally killing me.

Le Musée Gourmand du Chocolat

Future Chocolatiers

 

I think I may just switch careers and become an Oompa Loompa. I mean chocolatier, or do I? Besides, I don’t see why not. I’ve already got my partner, Kara, and I got to say I think we make a pretty good team. With our piping, tapping, and scraping skills, I think we’ve got a solid business. So, if my whole neuroscience plan doesn’t work out, well you know where to find me.

 

Getting our blessings from the real master 🙂

Well, back to the chocolate making. First, we got to learn how to make the first layer of our molds with some creamy dark chocolate. By the way, they sort of looked like mini Patrick Star’s from SpongeBob. Anyways, after 15 minutes in the freezer, we added some hazelnut and milk chocolate as our center layer and set it back in the fridge. We topped it off with some more dark chocolate and voila! We had created a masterpiece! Très délicieux! Obviously, we weren’t professionals so it was unfortunate that we made quite a bit of an artistic mess on the table. So, to make up for our “accidental” spills, we were forced to clean it up by eating it all. It was tough, but we had to do what was right. I mean, we were simply following in the footsteps of our role models.

Our moms have become the kids…

As we made our way around the museum, I started to think about how chocolate affects our daily lives. Before every exam I have had since high school, I make sure to get some chocolate in my system. Even just a little Hershey kiss. It became a psychological thing for me, but it turns out, chocolate might have some neurological effects on us.

Making our mark everywhere we go!

Chocolate contains cocoa flavanols, which are antioxidants and anti-inflammatory agents with known benefits to our cardiovascular health. These chemicals seem to accumulate in the hippocampus, a region that is involved in memory and learning. It is believed that these chemicals interact with various signaling pathways in our brain that help process long-term memories (Sokolov, 2013).

The hippocampus plays a role in processing short-term memory to long-term memory

In a recent study, Mastroiacovo et al. (2014) looks at the effects of chocolate on cognitive function. They recruited 90 elderly individuals who were assigned to consume a drink containing cocoa flavanol every day for 8 weeks. This drink, somewhat like chocolate milk, contained either high, intermediate, or low flavanol concentrations and their cognitive function was assessed using various mental examinations at the beginning and end of the 8-week period. There was improvement seen in all three groups, and more significantly in the high and intermediate groups. This may be an effect of cocoa flavanols increasing the blood flow in the brain. This is important because our blood transports nutrients and fuel to our body, and by increasing its flow, we are able to deliver more “brain food”. Aside from neurological benefits, they also saw a decrease in blood pressure, cholesterol and insulin levels (Mastroiacovo, 2014). All the more reason to consume chocolate, right?

Since this study was done in elderly individuals, I would really like to see if the impact of chocolate would be greater if this type of routine were done throughout childhood. It would definitely give us kids more reason to go chocolate crazy. They also looked at other health improvements (e.g. blood pressure) in addition to cognition, which will encourage investigation of other physiological effects caused by chocolate. 

Presenting chocolate Patrick Stars

 

 

Moral of the story in my opinion: Never say no to chocolate! What’s the worst it can do, make you smarter?

 

 

 

À bientot!

Swetha Rajagopalan

Bibliography

Crichton, G. E., Elias, M. F., & Alkerwi, A. (2016). Chocolate intake is associated with better cognitive function: The Maine-Syracuse Longitudinal Study. Appetite,100, 126-132. doi:10.1016/j.appet.2016.02.010

Mastroiacovo, D., Kwik-Uribe, C., Grassi, D., Necozione, S., Raffaele, A., Pistacchio, L., . . . Desideri, G. (2014). Cocoa flavanol consumption improves cognitive function, blood pressure control, and metabolic profile in elderly subjects: the Cocoa, Cognition, and Aging (CoCoA) Study–a randomized controlled trial. American Journal of Clinical Nutrition,101(3), 538-548. doi:10.3945/ajcn.114.092189

Sokolov, A. N., Pavlova, M. A., Klosterhalfen, S., & Enck, P. (2013). Chocolate and the brain: Neurobiological impact of cocoa flavanols on cognition and behavior. Neuroscience & Biobehavioral Reviews,37(10), 2445-2453. doi:10.1016/j.neubiorev.2013.06.013

Images Retrieved from these sites:

 https://tl.wikipedia.org/wiki/Hippocampus

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

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

 

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.

Screen shot 2015-06-21 at 1.54.02 PM

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.

11652008_10207024494441026_1186251255_n

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.

Screen shot 2015-06-21 at 2.02.23 PM

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.

11652279_923531177705260_102429369_n

Me eating un pain au chocolat

11638030_922815237776854_200798330_n

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

Musée du Chocolat

Before I even set foot in Paris, I had an agenda to tend to—buy every friend and family member enough chocolate to hold them over until their own trip to France. As (arguably) the biggest dark chocolate fan on the east coast, I have gone out of my way to make sure I try chocolate (in all forms) from all over Paris. I have run the gamut by trying chocolate bars from our favorite local grocery store (shout out to Mono Prix) to inhaling the chocolate pastries sold at Ladurée. Tending to my chocolate cravings in Paris turned out to be much easier than expected…

Chocolate Pastries at Ladurée (yum)

Needless to say, I was beyond excited when I saw that a trip to a chocolate museum was conveniently worked into our syllabus a day-off activity. Probably a bit too excited, the other students and I worked our way through the Parisian Metro and RER systems and arrived at “Choco-Story – Le musée gourmand du chocolat” earlier this week. Walking into the hands-on museum, we were hit with a wave of the sweet scent of chocolate, instantly putting everyone in a better mood. Part of our museum experience involved a chocolate workshop where we actually learned how to make bite-sized chocolates, and we luckily got to package the chocolates to bring back to our dorm.

Chocolate Museum: 28 Boulevard de Bonne Nouvelle, 75010 Paris

After our workshop where we somehow managed to make chocolate without destroying the museum kitchen, we waited for the pieces to cool in the fridge. As soon as our chocolate was cooled and ready to eat, I instantly ate maybe one too many pieces. Regardless, I was completely satisfied with my experience at the museum and our homemade treats. At this point, I’m sure you’re wondering why a chocolate field trip was worked into our neuroscience syllabus. Chocolate, aside from being central to Parisian culture, is responsible for producing pleasurable, hedonic effects and can therefore activate various brain areas (Rolls 2005). It has, for this reason not only been used as an incentive in various animal experiments, but its’ effects on changing activity in different brain areas have also been studied.

The neuroscience student in me wondered why some students were not as excited as I was about our chocolate museum expedition. Doesn’t everyone love chocolate? Why are there some people who don’t have chocolate cravings? Current neuroscience research is exploring the physiological implications behind cravings, emphasizing the brain systems that control our food intake. It turns out that people, like me, who crave chocolate actually show heightened physiological reactivity to images of chocolate. This means that there are measured changes in blood flow in different areas of the brain (such as the orbitofrontal cortex, the insula, ventral striatum and midbrain) in response to chocolate pictures (Small et al., 2001). What does this mean for choco-holics?

Spilling chocolate all over the kitchen floor....

A recent study tested the actual brain activity differences across individuals who craved chocolate and those who didn’t have these characteristic cravings (Asmaro et al., 2012). Researchers recruited undergraduates and asked them to fill out a chocolate-craving questionnaire, which was used to objectively measure “chocolate cravings”. After taking all of the data from these questionnaires, the researchers categorized the participants into one of two groups: chocolate cravers and non-cravers. The behavioral task of this study involved showing three types of images to both groups of participants. Both non-cravers and cravers were shown images falling under the following categories: chocolate, neutral and target. The chocolate stimuli category had pictures of dark or milk chocolate (yum), the neutral category had pictures of bland, uncooked foods (like pasta, for example) and the target stimuli category included random pictures of chairs (Asmaro et al., 2012).

There were two main sessions for this study: before eating chocolate and after eating a delicious piece of chocolate. In each of the two sessions, 220 images (100 chocolate, 100 neutral and 20 chairs) were presented in blocks. The participants (in both groups) were told to keep their eyes fixed on the screen as these images came up, and as soon as a target picture (a chair) appeared, participants had to press a key on a keyboard. After this task, the participants were asked to rate their craving for chocolate on a scale of 1 to 5. While this task was going on, researchers had an electroencephalogram along the patient’s scalp. An electroencephalogram is simply a tool that neuroscientists use to measure and record the electrical activity in the human brain. The reason they used an electroencephalogram in this case was to have a way to measure the brain response to these different, presented images. This actual brain response is commonly referred to as an “event-related potential” (Asmaro et al., 2012).

The researchers found that when the chocolate craving group was presented with a picture of chocolate, their brain activity indicated that they had a greater desire for chocolate overall. The non-craving group, however, had a lesser desire for chocolate after the task (Asmaro et al., 2012). This shows that presenting the chocolate stimuli actually caused different neurological responses across the two groups—cravers and non-cravers. If we take a step back and apply this back to my chocolate obsession, it is probable that I may have had different areas of my brain activated when I walked into the chocolate museum and saw all of the chocolate merchandise and pictures (when compared to some of my not so excited classmates).

Cooling chocolate (the French way...)

Asmaro et al. (2012) also showed that in non-cravers, the early changes in an area of the brain disappeared after eating some chocolate. This suggests that certain brain mechanisms control the otherwise natural urge to continue to eat chocolate in non-cravers (Asmaro et al., 2012). In cravers, however, a similar area of the brain (the orbitofrontal cortex) showed no changes in activity even after eating chocolate. What does this mean for us chocolate lovers, then? Turns out certain areas in our brain, such as the orbitofrontal cortex, are more likely to tell us to stop eating chocolate if we are classified as a “non-craver”. For us cravers, however, chocolate is a “wanted stimulus with a high motivational value” (a value that we subjectively place on it) and so our brains don’t really tell us to stop as readily as the brains of our fellow non-cravers. This is due to the fact that we have grown to appreciate and place immense value on chocolate.

Turns out, studies on the effects of chocolate on the brain are quite popular—mainly because they provide us with insight on consummatory and dietary patterns in humans.  The question is now: are you a craver or non-craver, and what are you going to do about it? If you’re anything like me, I’ll see you at the local bakery scoping out the best chocolate pastries.

 

-Noareen Ahmed

 

References:

Asmaro D, Fern J, Valery S, Isabel T, Patrick C, Mario L (2012) Spatiotemporal dynamics of the hedonic processing of chocolate imags in individuals with and without trait chocolate craving. Appetite 58: 790-799.

Rolls E, McCabe C (2007). Enhanced affective brain activations of chocolate in         cravers vs. non-cravers. European Journal of Neuroscience 26: 1067–1076

Small D, , 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.