Author Archives: Noareen Ahmed

Confessions of a Coffee Addict

Posted on June 25, 2013 | 2 comments

With the addition of new coffee vendors on Emory’s campus over the past three years, combined with the excellent surrounding breakfast hotspots, I have become one to regularly appreciate and truly enjoy a hot cup of coffee. Whether the coffee be from Starbucks, Rise-n-Dine or Dunkin Donuts, I am victim to daily expenditure at these vendors for my morning (and sometimes evening) caffeine fix. Now that my time in Paris is approaching its end, I will readily admit that I had routed the closest Starbucks locations to my dorm and to the building where we take classes (before my departure from New York). I saved those directions in my phone; anticipating daily visits to this familiar coffee shop.

My pre-departure routing of Starbucks to the Accent center (where we take classes)

When I realized that it would be a daily struggle to somehow go to Starbucks before my early morning class (thanks to the reliability of the French subway system), I decided to give the conveniently located French coffee (on campus) a chance. My first experience with French café was at the Cite Universitaire cafeteria, as I was presented with a Dixie-cup size equivalent cup of black coffee. No sugar, no milk…but I was pleasantly surprised. I didn’t realize how strong the coffee would be and I can safely say that 3 cups of the café coffee was overkill…

All throughout Paris, I have noticed that the café comes in one size: about a quarter of the size of the regular coffee we get back in America. The coffee is quite deceiving, as the small cup actually keeps me energized despite its miniscule volume. I quickly realized that coffee in itself is a part of French culture, as many cafes throughout the city orient their tables and chairs to face the streets—this way, people can enjoy a cup of coffee and “people watch”. I rarely see Parisians eating lavish breakfasts (doesn’t stop me though…); rather, they enjoy a simple black coffee with the morning paper. French culture, to me, seems to emphasize simplicity and reservation. A cup of coffee, then, serves as a means to collect your thoughts and appreciate the beauty of France while simultaneously obtaining a needed jolt of energy. A cup of coffee transcends the traditional role of a breakfast drink, as “une tasse de café” is readily available (and encouraged) at any time of day.

French breakfast at a local restaurant (notice the tiny coffee...)

One of the classes we are taking here is related to body enhancement and the new, innovative technologies that can alter normal human function. During class one day, Dr. Crutcher shared with us some research that suggested the caffeine fix from our morning cups of coffee actually yields some physiological effects besides just enhanced alertness. In the past, researchers found that caffeine can increase anxiety in the short run, but increased doses of caffeine over time (via more coffee, for example) can lead to a diminished effect because of the build up of tolerance (Rogers et al., 2010). Recent research suggests that caffeine, readily found in coffee, may modify the way the different brain areas react to social threats (Smith et al., 2012). What are the neurological implications of this? Smith et al. (2012) set out to determine if there really was a relationship between anxiety, threatening signals, caffeine and the brain.

How did they do this study? After obtaining a group of subjects, the researchers gave the participants in this study received a fixed amount of either caffeine or placebo in two different sessions. During each session, the participants were placed in an MRI machine that would give researchers an fMRI scan (functional magnetic resonance image). An fMRI is basically a way to measure the changes in blood flow in the brain. Changes in blood flow in the brain represent changes in activity and activation in the different areas of the brain. (For example, if an area of the brain is in use, then there is increased blood flow in that area.) While in the MRI machine, participants were asked to perform an “emotional face processing task” (EFPT). This task involved participants being presented with different faces, each representing different emotions, and they had to match the presented face to a target face at the top of the screen. (Similar to a matching game!) After seeing the faces and doing the matching task, the participants would rate their anxiety and mental alertness (compared to before the task) via a questionnaire. Researchers also measured their blood pressure (before and 2 hours after the treatment of either the placebo or caffeine) (Smith et al., 2012).

Turns out that when the participants who were administered caffeine saw the threatening faces, that is the angry and fearful faces during the EFPT, there was increased activation of a brain area called the “midbrain periaqueductal gray area” and decreased activation in another area called the “medial prefrontal cortex” compared to the placebo group (Smith et al., 2012). Participants who received the caffeine dosage had higher self-rated anxiety on the questionnaires and their diastolic blood pressures were higher also! However, the exact neural mechanisms and implications of how these areas actually process threatening images and scenarios are still unknown (Smith et al., 2012). So what was the point of this study then? Smith et al. (2012) suggest that these brain areas, that showed changes in activity, are actually related to social threat processing and anxiety in humans. Because there were actual changes in blood flow in these areas in response to threatening or anxiety-inducing faces, only in the light of a caffeine dosage, it seems to be that caffeine is modifying the patterns of activation in the brain. A daily dose of caffeine, in the form of coffee for most of us, then, can possibly affect the way we perceive threats and can possibly affect how anxious we are compared to when we do not consume caffeine.

Yum

As with almost everything that seems too good to be true, in this case a delicious cup of French coffee, this study seems to suggest that loading up on multiple cups of coffee a day might not be the best idea. But, I don’t really plan on giving up my black Americano any time soon (especially since I’m leaving France soon and am already having French coffee withdrawal).

-Noareen Ahmed

References:

Rogers, P, Hohoff C, Heatherley S  (2010) Association of the anxiogenic and alerting effects of caffeine with ADORA2A and ADORA1 polymorphisms and habitual level of caffeine consumption. Neuropsychopharmacology 35: 1973–83.

Smith J, Lawrence D, Diukova A, Wise R, Rogers P (2012) Storm in a coffee cup: caffeine modifies brain activation to social signals of threat. Scan 7: 831-840

2 Comments

Posted in Neuroscience

Tagged , , , ,

Musée du Chocolat

Posted on June 18, 2013 | 4 comments

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.

 

4 Comments

Posted in Neuroscience

Tagged , , ,

Musée du Louvre

Posted on June 11, 2013 | 14 comments

The overwhelming feeling landing in Paris just a few short weeks ago can only be described as a combined wave of nervousness, anxiety and excitement.  I didn’t expect to feel that sensation again so soon, but walking into the Louvre brought the same, overwhelming rush. I was amazed by the architecture of the building and its’ perimeter and tried not to look like a typical tourist stopping to take pictures along every step of the way. After attempting to blend in with the crowd by buying some “French” coffee, we grabbed a map of the museum and (blindly) picked a starting point.

Musée du Louvre

We started with the Ancient Egyptian exhibit, which was confusing given the French descriptions mounted by all of the pieces. The intricacies of the hieroglyphics, artwork and tools, however, transcended the language barrier. After walking through, we were tired (we had climbed the Eiffel Tower earlier that day) and decided to head to one more piece before completing our day—the famous Mona Lisa.

Ancient Egyptian Art

Following the crowd, we made our way to the other side of the museum and quickly saw the international amalgamation surrounding this infamous painting. How is it that this one painting can draw so much attention from so many different people? Part of the interest in this picture lies in the mystery behind its creation—why did Leonardo da Vinci paint this picture? Who is the woman depicted here? Is she real? These questions are unanswered and add to the mystery associated with this artwork. One of the elements of this painting that interests people from across disciplines and countries is the ambiguity in Mona Lisa’s smile.  When we look at this infamous smile in the context of neuroscience, we should consider the role of visual perception. Visual perception in itself is a bridge between art and science, as this is the type of information processing that takes different visual stimuli from our environment and processes them into a “single”, interpretable unit. Visual perception is broken down into different elements such as visual closure, memory, form constancy, spatial skills and more (Chakravarty 2011). All of these factors contribute to how we perceive the outside world via our vision.

Scientists have taken this described cognitive approach to vision and have applied it to different areas of the brain. They have found that vision and interpretation of what we see relies on multiple brain areas. The primary visual area is referred to as V1, and next to this area are different, specialized regions such as V3 (recognizes the shape and size of an object), V4 (color perception) and V5 (essential in identifying object motion) (Chakravarty 2011).

The Mona Lisa

Taking a step back, it is clear that there are multiple parts of the brain with their own specific, intricate mechanisms that can affect the way faces and objects, for example the Mona Lisa, can be perceived and processed across any given population. The human visual system has allowed us to, over time, develop specific visual skills that correspond to face perception (Haxby et al., 2000). For example, individuals with brain damage in the ventral occipitotemporal cortex (an area in the brain associated with visual perception) have difficulty in recognizing faces—but can recognize objects with ease (Haxby et al., 2000). This condition, prosopagnosia, is one that supports the claim that there are very specific areas in the brain associated with face perception—perhaps providing a neurological reasoning behind the fascination with the Mona Lisa. The fact that this is a portrait of a mysterious face might be driving the worldwide fascination.

When actually getting a better look at the Mona Lisa after pushing through the crowds of people, the neuroscience student in me couldn’t help but wonder how many different neurobiological systems were working in order for me to appreciate this piece of art. I had to focus on the picture, discern the face from the background, take in account of the colors, recognize that this was a portrait, and attempt to make associations and recall what I had learned about this piece in my high school art class. Aesthetic preference is yet another factor that has significant neurological underpinnings. Cela-Conde (2011) found, through various neuroimaging studies, that certain areas in the brain (the hippocampus, parahippocampal gyrus and the amygdala) are all actively engaged when individuals are aesthetically pleased with a piece of artwork. When patients with neurological conditions (in which these areas degenerate) are presented with previously “pleasing” pieces of artwork, the patients show a completely altered taste and preference. This supports that these areas of the brain have some influence over the cognitive perception and appreciation of artwork. Similarly, studies have reported that damaging the amygdala (an area of the brain primarily associated with emotion) can alter artistic, visual preference. Individuals with amygdala damage generally expressed a liking for “…geometrical shapes, landscapes and color arrangements” when compared to the healthy, control groups (Cela-Conde et al., 2011).

Mona Lisa Selfies...

Perhaps the fascination with the Mona Lisa is brought about by the evolutionarily driven sensitivity to faces. Or, maybe there is a genetic predisposition in some of our brain’s visual areas to appreciate certain types of artwork. Some scientists even suggest that the ambiguity in her smile activates area V5, an area of the brain involved in perceiving movement, which enhances aesthetic appeal (Chakravarty 2010). Regardless of the reasoning, there are complex neurological mechanisms by which we process not only the Mona Lisa, but also every other sculpture, painting or realistically anything in our visual field. Visual perception in itself relies on cognitive theories and activation of various brain areas to yield some form of appreciation of art—now try not to think about that next time you go to a museum.

Written by: Noareen Ahmed

References:

Cela-Conde C, Agnati L, Huston J, Mora F, Nadal M (2011) The neural foundations of aesthetic appreciation. Progress in Neurobiology 94: 39-48.

Chakravarty A (2010) Mona Lisa’s smile: A hypothesis based on a new principle of art neuroscience. Medical Hypotheses 75: 69-72.

Haxby J, Hoffman E, Gobinni M (2000) The distributed human neural system for face perception. Trends in Cognitive Sciences 4: 223-233.

14 Comments

Posted in Neuroscience

Tagged , , ,