Tag Archives: Brain

Walk-a-holic

Google Map directions of the 5-minute walk from the ACCENT center to Pause Café.

“It’s a 20-minute walk,” sighed my American friends, complaining that it was “too long.” It was our first week in Paris on our study abroad program, and we were planning on going to a café. After Google maps indicated that the metro stop was far from the original café, we ended up going to Pause Café. It was on the corner of the street near the ACCENT center, where our daily classes are held.

 

Image of Pause Café.

I was shocked by the lack of energy that we had. Looking around us, Parisians were walking from place to place without breaking a sweat. Walking for twenty minutes, even thirty, was typical for a Parisian. This got me thinking, how different would my life be if I lived in Paris. In Atlanta, shops and restaurants were far apart, sidewalks were narrow, and the city was difficult to explore without a car. But in Paris, everything was nearby, and sidewalks were wide. If I were to walk this much every day for the rest of my life, how would that impact my health?

Exercise is known to have many health benefits. A fact that has been ingrained in my mind since elementary school. What I knew was that exercise could prevent heart attacks and diseases, but not its effect on the brain.

Researchers show that exercise improves memory, specifically our memory of certain places and events (Cassilhas et al., 2016). The anterior hippocampus provides us with the ability to imagine our house and move around our neighborhood (Zeidman and Maguire, 2016). As we get older the hippocampus decreases in volume resulting in increased forgetfulness (Raz et al.,2005). However, there may be a way to halt those effects and possibly reverse them.

Erickson et al. (2011), reveal in their study that physical exercise improves our long-term memory, specifically our navigational memory. By exercising 3 times a week for one-year, participants had an increase in the volume of their anterior hippocampus. However, participants who did not exercise had a decreased anterior hippocampal volume. Overall, the study showed that only the decreased volume in the anterior hippocampus can be reversed with exercise, but not other parts of the hippocampus. This is a well-designed experiment because 120 participants were involved in the study, which makes the results more applicable to the general public by representing different types of people in the population. The differences in the size of the anterior hippocampus can be better observed and statistically tested with this large number of participants. Further, by testing participants prior to the exercise protocol, after 6 months, and after one year, we can look at the effects of exercise on the anterior hippocampal volume both in the short-term and long-term.

Graphs of the increase in the volume of the anterior hippocampus for the exercise group (blue line) compared to the decrease in the volume of the anterior hippocampus for the control (red line), evident in both the left hemisphere and the right hemisphere of the hippocampus.

Writing this now, I regret missing that 20-minute walk because I now know that a little exercise every day goes a long way in improving my memory. This leaves me wondering, is there a certain time frame when I should be exercising after learning new material?

Researchers performed a study to test whether there is an appropriate time to exercise after learning to improve memory recall (Van Dongen et al., 2016). Participants were assigned into three groups; those who exercised immediately, those who exercised after 4 hours and those who did not exercise. They learned to associate a certain object with a location (refer to image below).The researchers then asked the participants to recall that association. The results showed that exercising 4 hours after learning instead of immediately after enhanced participant’s ability to remember those associations compared to those who did not exercise. Hence, properly timed exercise can enhance long-term memory. The researchers strengthen their conclusion by controlling for problems that could affect the results.Such as having half the participants perform the task at 9AM, while the other half perform it at 12PM. This accounts for the differences in performance at different times of the day, which ensures that improvement in memory recall is occurring due to exercise.

Image of task protocol: associating an object with a location. The orange box represents the study phase, while the blue box represents the testing phase.

So, my elementary school teacher was right after all. Exercise is important for a healthy heart and, as it turns out, a healthy memory. Not only does this motivate me to exercise more often, but also, these studies give me hope for new intervention methods for patients with memory recall deficits. An example would be Alzheimer patients, who struggle with navigating the world (Weller et al., 2018). Another would be patients with major depressive disorder, who have memory impairments in encoding and recalling information (Gourgouvelis et al., 2017). It is cases like these that highlight the importance of understanding the impact of exercise on memory.

Now, when my friends and I have the option between using the metro or walking for 20-minutes, we choose the latter. Living in Paris for 4 weeks today, I have assimilated with the Parisian way of life. I am now able to walk in Paris for hours without the slightest soreness in my legs. It has become my new way of life.

 

References:

Cassilhas, R. C., Tufik, S., & de Mello, M. T. (2016). Physical exercise, neuroplasticity, spatial learning and memory. Cellular and Molecular Life Sciences, 73(5), 975-983.

Erickson, K. I., Voss, M. W., Prakash, R. S., Basak, C., Szabo, A., Chaddock, L., … & Wojcicki, T. R. (2011). Exercise training increases size of hippocampus and improves memory. Proceedings of the National Academy of Sciences, 108(7), 3017-3022.

Gourgouvelis, J., Yielder, P., & Murphy, B. (2017). Exercise promotes neuroplasticity in both healthy and depressed brains: an fMRI pilot study. Neural plasticity, 2017.

Raz, N., Lindenberger, U., Rodrigue, K. M., Kennedy, K. M., Head, D., Williamson, A., … & Acker, J. D. (2005). Regional brain changes in aging healthy adults: general trends, individual differences and modifiers. Cerebral cortex, 15(11), 1676-1689.

Van Dongen, E. V., Kersten, I. H., Wagner, I. C., Morris, R. G., & Fernández, G. (2016). Physical exercise performed four hours after learning improves memory retention and increases hippocampal pattern similarity during retrieval. Current Biology, 26(13), 1722-1727.

Weller, J., & Budson, A. (2018). Current understanding of Alzheimer’s disease diagnosis and treatment. F1000Research7.

Zeidman, P., & Maguire, E. A. (2016). Anterior hippocampus: the anatomy of perception, imagination and episodic memory. Nature Reviews Neuroscience, 17(3), 173.

L and R: Brain and Politics

Do you hear the people sing? Singing a song of angry men? It’s the music of the yellow vests who shut down subway stops on weekends.

As dedicated as I have been to eating Saturday brunch, the yellow vests (gilets jaunes to the French) have been just as dedicated to convening on Saturday afternoons to protest. The yellow vests are a French populist group mostly made up of members of the working and middle classes who express frustration about slipping standards of living. For the past few months since October 2018, the yellow vests have been showing up every weekend in major Paris locations to protest for lower fuel taxes, redistribution of wealth, an increase in minimum wage, and even the resignation of French President Macron (Diallo, 2018). I remember reading throughout the semester New York Times articles about these protests back when I was in America, and it all seemed very removed from where I was at the time. But now, there is no way to forget when every weekend I receive an email from our study abroad program center about the yellow vests’ path of protest for the weekend and have to track what popular tourist areas will be out of commission for the day. Indeed, Les Mis was not all that misleading. It seems that since the beheading of Queen “Let Them Eat Cake,” the French people have not been able to shake the love of a good revolution or protest from their society. But it is definitely not only the French that enjoy political demonstrations; from 1960s UC Berkeley students to my pink knitted hat compatriots, America has a its own unique history with political movements. I wanted to know – what is it about politics that seems so intrinsic and enticing that people are motivated to come out, rain or shine, to walk around and yell collectively??

major sites of closure yellow vest protests have caused

Part of the reason that being a part of a political movement can be so enthralling is the association with a political party that people flaunt. This gives members of the group a sense of belonging, which is a basic human need involving complex emotions of love, pride, and emotional excitement (Jasper, 2011). In America and many other nations, there is a divide between the liberal left and the conservative right. The ideological labels of “left” and “right” have been around since the time Christian symbolism associated right with “liking for or acceptance of social and religious hierarchies” and the left with “equalization of conditions through the challenge of God and prince.” This fundamental difference in political ideology has remained relatively intact throughout the centuries since then (Jost, 2014). While for many year scientists have assumed political orientation to be solely the result of upbringing and environmental factors, there have recently been studies identifying biological influences on individual’s political attitudes. This field of study falls under neuropolitics, or the study of how neuroscience and political science intersect (Schreiber, 2017).

In a 2011 study that tried to elucidate whether brain structure differences could be linked to political associations, the brain region of the anterior cingulate cortex (ACC) was studied. The ACC has connections to both the “emotional” limbic system” and “cognitive” prefrontal cortex of the brain and is involved with conflict monitoring – the task of detecting conflicts in information processing and then signaling when increased cognitive control must be recruited (Yeung, 2013). The 90 young adult test subjects were first asked to self-report their political attitude on a five-point scale ranging from “very liberal” to “very conservative.” Although a simple scale, this self-reported result has been shown to accurately predict voting behavior. Magnetic resonance imaging (MRI) scans that show detailed images of the brain were then taken of each subject to assess differences in volume of ACC. Results of their scans after controlling for age and gender variables showed that increased gray matter volume in the ACC was significantly associated with liberalism. This hinted that individuals with larger ACC may tolerate uncertainty and conflicts better and allow them to hold more liberal views. The same study also looked at the amygdala, which is involved in processing emotional responses such as fear and aggression, to look for links between gray matter volume of amygdala and political ideology. By evaluating amygdala volume and political attitudes, researchers saw there was an increased amygdala volume associated with conservatism, suggesting that conservatives respond to threatening situations with more aggression and have a heightened sensitivity to fear (Kanai et al., 2011).

a. Results showing ACC volume in comparison with political ideology
b. Results showing amygdala volume in comparison with political ideology

Of course, the question of “which came first, the chicken or the egg?” also applies here: are people more inclined to lean a certain political direction based on biologically predetermined brain differences or do people’s political ideology lead to slight but significant changes in brain structure? I would have been interested to hear if the researchers had any thoughts on this or had long-term data comparing subjects to look for correlations that may have helped answer this question. The researchers also mention a stipulation to their results that abstract reasoning and thinking often requires widespread brain regions and cannot be traced back to one specific brain region. Additionally, a recent review of neuropolitics warns people of the “pathologisation of politics” which essentially chalks up political problems into biological deviations (Altermark & Nyberg, 2018). I think this is especially pertinent as weaponizing neuroscience in order to reduce those you do not agree with is not the purpose of studying the brain. Overall, no matter left or right, remember the brain functions best with both working together!

 

Bibliography

Altermark, N., Nyberg, L. (2018) Neuro-Problems: Knowing Politics Through the Brain. Culture Unbound, 10, 31-48.

Diallo, R. (2018, December 19). Why are the ‘yellow vests’ protesting in France? Al Jazeera, Retrieved from https://www.aljazeera.com/indepth/opinion/yellow-vests-protesting- france-181206083636240.html

Jasper, J.M. (2011) Emotions and Social Movements: Twenty Years of Theory and Research. Annual Review of Sociology, 37, 285-303.

Jost, J.T., Nam, H.H., Amodio, D.M. & Van Bavel, J.J. (2014) Political Neuroscience: The Beginning of a Beautiful Friendship. Political Psychology, 35, 3-42.

Kanai, R., Feilden, T., Firth, C. & Rees, G. (2011) Political orientations are correlated with brain structure in young adults. Curr Biol, 21, 677-680.

Schreiber, D. (2017) Neuropolitics: Twenty years later. Politics and the Life Sciences, 36, 114- 131, 118.

Yeung, N. (2013). Conflict monitoring and cognitive control. In: Oxford Handbook of Cognitive Neuroscience (Ochsner, K. and Kosslyn, S., eds), Oxford University Press (in press).

Image 1: https://www.usnews.com/news/world/articles/2019-02-09/more-violence-in-paris- as-yellow-vests-keep-marching

Image 2: https://www.bbc.co.uk/news/world-europe-46499996 Image 3: Kanai et al., 2011

vitamin G for green

After getting off of the train in Avignon and feeling the sun hit my un-sunscreened shoulders, my mood undeniably approved. It was a definite upgrade from the cold and drizzly weather we had just escaped from in Paris. Whether it was the sunshine induced drowsiness or the gelato produced lethargy, I seemed to move at a much slower and relaxed pace this weekend. I often find myself hustling to get from departure point to destination during the week, sighing impatiently at the slow walkers leisurely strolling on the sidewalk who have the audacity to slow me down.  In Provence, I didn’t feel the need to obsessively make schedules and instead just enjoyed the new surroundings.

The southern France, creek wading Irena is definitely much more carefree and relaxed than urban Paris, coffee chugging Irena.

I thought back to our journal topics about Van Gogh and his mental health and remembered how the film we watched had portrayed his mood. Van Gogh had written about the countryside in Arles and how it had improved his spirit (up until that whole ear incident). Van Gogh talked about how much time he was spending outside and how productive his work output was during the time he could paint en plein air. I think this is something that we can all relate to; the first day of being outside in the warmth and sunshine after weeks of winter stuck inside avoiding the Atlanta rain can make me feel like I escaped something just shy of seasonal affective disorder. Well besides you and me, it seems that others have been onto this phenomenon for a while now too. In fact, the term “ecotherapy” has been coined as “an umbrella term for a gathering of techniques and practices that lead to circles of mutual healing between the human mind and the natural world from which it evolved”  (Chalquist, 2009).

Courtyard garden in an Arles hospital where Van Gogh stayed briefly and his painting of it

It has been documented that merely looking at nature or natural elements can provide restoration from stress and mental fatigue while reducing feelings of anger, frustration and aggression. This has indicated that the “aesthetic experience of nature” can play a beneficial role in affecting mood (Groenewegen, van den Berg, de Vries, & Verheij, 2006). Some studies utilize the visual sensory system in order to test the effects of nature images on neural processing and well-being; however, the experience of nature cannot be reduced to singular modalities but rather is holistic and encompasses all the sensory systems in the body. Therefore, many of the studies that I looked at examined and quantified aspects of well-being that are harder to measure. A study of 57 people with serious and persistent mental illness was conducted where they participated in an outdoor adventure program involving weekly full day outings for 9 weeks. At the end of the study, there were statistically significant increases on the Generalized Self-Efficacy Scale (a 10-item psychometric scale that assesses optimistic self-beliefs to cope with a variety of difficult demands in life) in the experiment group compared to the control group that did not undergo outdoor exposure. The experimental group also showed significant reductions in scores on the Anxiety and Depression subscales of the Brief Symptom Inventory (BSI), a test that evaluates psychological distress and psychiatric disorders. Patients with affective or schizoaffective disorders, mental health disorders we discussed Van Gogh having the possibility of having, showed an increase in scores on the Trust and Cooperation Scale, and decreased BSI Hostility and Interpersonal Sensitivity (Kelley, Coursey, & Selby, 1997).

General mechanisms to explain relationships between green space and health, well-being, and social safety

In a 2010 meta-analysis (a statistical procedure for combining data from multiple studies) that analyzed 10 UK studies of environment and health that involved over 1252 participants, every green environment improved both self-esteem and mood with the presence of water generating greater effects. Outcomes were identified through a subgroup analyses, and dose-responses were assessed for exercise intensity and exposure duration. Based on this meta-analysis, the mentally ill showed one of the greatest self-esteem improvements based on exposure to green environments and nature (Barton & Pretty, 2010).

The number of participants, activity types, environments, and cohorts from each study from the meta-analysis  

Ecotherapy studies have also begun a foray into a crossover intervention with art therapy, as both approaches have research supporting their success in the reduction of physiological and psychological symptoms associated with a variety of diagnoses in numerous settings. While a statistically significant correlation between ecotherapy and art therapy has not yet been found, there are many qualitative and case-study research designs that demonstrate the effectiveness of art and eco-therapy interventions (Bessone, 2019).

This weekend in Arles, we saw the various locations around town that Van Gogh drew inspiration from for his paintings, making it quite evident that he was closely connected with his environment. While eco/art therapy are no substitutes for comprehensive mental health care, I hope that Van Gogh was able to find temporary reprieve in his artistic work and the natural beauty of southern France during his time there.

Landscape picture of Arles, France

 

Bibliography

Barton, J. & Pretty, J. (2010) What is the Best Dose of Nature and Green Exercise for Improving

Mental Health? A Multi-Study Analysis. Environmental Science & Technology, 44, 3947-3955.

Bessone, E. (2019) Implications and Applications of Eco-Therapy on Art Therapy. Expressive Therapies Capstone Theses. 155.

Chalquist, C. (2009) A Look at the Ecotherapy Research Evidence. Ecopsychology, 1, 64-74.

Groenewegen, P.P., van den Berg, A.E., de Vries, S. & Verheij, R.A. (2006) Vitamin G: effects of green space on health, well-being, and social safety. BMC Public Health, 6, 149.

Kelley, M. P., Coursey, R. D., & Selby, P. M. (1997). Therapeutic adventures outdoors: A demonstration of benefits for people with mental illness. Psychiatric Rehabilitation Journal, 20(4), 61-73.

Image 1: my own picture

Image 2: from https://www.marvellous-provence.com/arles/what-to-see/in-the-footsteps-of-van-gogh

Image 3: from Groenewegen, van den Berg, de Vries, & Verheij, 2006.

Image 4: from Barton & Pretty, 2010

Image 5: from https://steemit.com/landscapephotography/@schmidthappens/landscape-photography-the-inspiring-arles-france

 

Georgia On My Mind

White earplugs hang from the ears of every person in my view. Surrounded by people from all sides, I heard a mixture of different songs, different artists, and different genres echo in the quiet metro. Every day, at 8:55 AM I  got on the metro at La Motte-Picquet- Grenelle and 16 stops later, I  got off at Ledru-Rollin, where my classes are. Even though I  saw different people rushing in and out of the metro, I never failed to spot the white earphones or ear pods in people’s ears.

The Metro line M8 taken from La Motte-Picquet- Grenelle station and the 16 stops before arriving to Ledru-Rollin station (the start and stop are identified by the red boxes).

On the streets of Paris, people of various ages walked to the beat of their songs pumping in their ears. So why are Parisians infatuated with music?

A picture of a Parisian on the metro listening to music.

It turns out that our brain interprets music as a pleasant and rewarding experience (Ferreri et al., 2019). In scientific terms, a well-known neurotransmitter, dopamine, is a chemical substance that is released by neurons when we experience pleasure. An experiment performed by Ferreri et al., 2019 studied the role of dopamine on feelings of pleasure and motivation to listen to music. They did that by  having volunteer participants receive orally either a chemical that enhances dopamine, prevents dopamine, or does not affect dopamine in their brains while they listen to music. The results show that the participants who  take the dopamine enhancer  have increased feelings of pleasure and motivation to listen to music, while the opposite effects are seen for individuals who  take the dopamine inhibitor. So, people like Parisians who listen to music experience a rush of pleasure. A simple analogy is that an individual’s brain reacts similarly when listening to music as it does if that individual takes potent drugs, such as cocaine.

The one thing that is constantly surrounding us anywhere in the world is music, whether we are at a supermarket, a café, or a mall. We are constantly being stimulated by music as it is becoming an integral part of every culture. Not only does it touch our mood and emotions, but also it influences our thoughts. Have you ever listened to a song and started to think about all your future life decisions? Of a memory with your friends? Of the challenges you have been through?

Well, researchers show that stronger emotions are experienced when we involve our personal memories  while listening to music whether we find it pleasant or unpleasant (Maksimainen et al., 2018). When we enjoy a song, our memories of certain events heighten our emotional response. This is why when we listen to our favorite song, we start remembering things that happened to us and we feel like we are experiencing these emotions again. But wait, there’s more…music affects parts of the brain that are involved in processing information that go beyond our emotions.  One study examines a circuit of 3 main networks in the brain of preterm compared to full term newborns (Lordier et al., 2019). The findings revealed that preterm infants who are introduced to music in the intensive care unit at the hospital have significantly more connections in the orange and blue networks compared to preterm infants who were not exposed to music. The brain regions involved in the orange network are the superior frontal gyrus, the auditory cortex, and the sensorimotor area, which are involved in cognitive control, auditory processing and motor control, respectively. The brain regions involved in the blue network are the thalamus, precuneus, and parahippocampal gyrus, which are involved in processing information from our senses, recall of memories and encoding and retrieval of memories, respectively. The important take away is that preterm infants who are exposed to music have brain networks that develop more similarly to full term newborns. This means that music plays a role in enhancing our brain networks, which indirectly affects higher cognitive functions.

An image of the brain that shows the networks of interest in the Lordier et al. (2019) study.

Now, as I stand in the metro unlike my first day in Paris, I am the one with the white earphones hanging from my ears. As I listen to country and pop songs, I enjoy every moment of my metro ride instead of counting the minutes  till I reach my destination. I am relaxed, experiencing my own rush of pleasure. Each song evokes in me a different memory, a different feeling than the last. Listening to Ray Charles, Georgia on my mind, I reminisce about my experiences in Atlanta.  Music, a part of our daily lives that we often disregard, actually has a strong influence on our brain network and emotional experiences.

An image of me on the metro with my earphones in, listening to music after spending 2 weeks in Paris.

References:

Lordier, L., Meskaldji, D., Grouiller, F., Pittet, M., Vollenweider, A., & Vasung, L. et al. (2019). Music in premature infants enhances high-level cognitive brain networks. Proceedings Of The National Academy Of Sciences, 201817536. doi:10.1073/pnas.1817536116

Ferreri, L., Mas-Herrero, E., Zatorre, R., Ripollés, P., Gomez-Andres, A., & Alicart, H. et al. (2019). Dopamine modulates the reward experiences elicited by music. Proceedings Of The National Academy Of Sciences116(9), 3793-3798. doi:10.1073/pnas.1811878116

 Maksimainen, J., Wikgren, J., Eerola, T., & Saarikallio, S. (2018). The Effect of Memory in Inducing Pleasant Emotions with Musical and Pictorial Stimuli. Scientific Reports8(1). doi:10.1038/s41598-018-35899-y

bottoms up! cognition down?

drinking but make it ~~patriotic~~

Walking around the city of Paris, it is hard to miss the fact that we are in a country submerged in a long, liquid history with wine and a current population dedicated to upholding this wine drinking culture.  “For many individuals, drinking wine has become an identity-building process by which they become part of a new form of civil community constructed around a nostalgic view of a rural and authentic France” (Demossier, 2010, p. 13). Apparently, the French are quite a nostalgic bunch then, and at all times of the day. Whether it’s with a well-plated charcuterie board, a medium rare steak, or sans any food in front of them, I cannot recall a time when I did not walk through a Paris street without seeing anyone sitting outside at a café terrace without a glass of wine accompanying them.

a typical scene of Parisian merriment

As a nation with casual drinking during meals ingrained into the collective psyche, I was interested in seeing whether this difference in mentality would manifest in a difference in drinking habits – binge drinking in particular – among the young people of France and America. Binge drinking (BD) is typically defined as heavy alcohol use of four or five drinks over a short period of time. From 2009 to 2013, the prevalence of those partaking in BD among university students in France was about 30% in the period of a month (Tavolacci et al., 2016). During this same period of time, the percent of 18-22-year-olds in America binge drinking within a month wavered around 40% (White and Hingson, 2014). The underlying factors leading to the prominence of binge drinking is a bottle to be uncorked another time, but today I will be looking into the effects of binge drinking on cognitive function in young people.

We’ve all seen the short-term side effects of binge drinking – in fact I think I saw some of it walking around the Bastille area of Paris one day after dinner – but what about the unseen and long-term effects in the brain? As binge drinking is usually associated with those of college age whose primary occupation is often school, I wanted to see how much researchers know about what is happening to a brain and its function with frequent alcohol use.

In a 2009 study, 42 binge drinkers and 53 controls from between age 18-20 were tested. Scalp electrodes were used to measure event-related potentials (ERPs), which are measured brain responses that are a result of a specific sensory, cognitive, or motor event and a way to evaluate brain function. Subjects were asked to perform a visual working memory task, a task where visual information must be remembered and manipulated quickly when prompted, and then the components of their ERPs were compared. The results indicated that there was the presence of an electrophysiological difference between the binge drinker and the control group, and that higher levels of attentional efforts were required from the binge drinking group to differentiate between relevant and irrelevant information to effectively process working memory (Crego et al., 2009).

 

an example of the components of what an ERP may look like based on electrode measurements

 

Another study in 2011 tested 40 binge drinkers (13 females, 27 males) and 55 controls (24 females, 31 males) between the ages of 16 to 19. Researchers conducted neuropsychological testing, substance use interviews, and a spatial working memory (SWM) task, which requires retention and manipulation of visuospatial information, during functional magnetic resonance imaging (fMRI). Links between BD status and gender were found in brain regions spanning the bilateral frontal, anterior cingulate, temporal, and cerebellar cortices. In all regions, female binge drinkers showed less SWM activation than female controls; however, male binge drinkers actually showed greater activation of SWM which linked to better spatial performance (Squeglia et al., 2011). The results of this study seemed to indicate that females may be more vulnerable to the neurotoxic effects of binge drinking during adolescence, while male brains may be more resilient to the harmful effects of binge drinking (where does the male privilege end??).

an example of a simple spatial working memory task

While ERPs and SWM are ways to assess brain function, I believe they can’t fully encompass cognitive performance, which synthesizes aspects of memory, attention, and reasoning. Overall, I believe the exact effects of binge drinking on the human adolescent brain will always be difficult to elucidate because of the many confounding factors that cannot be controlled for in correlational studies. However, this does not mean that this topic should be any less deserving of research because of the important implications the results can have for adolescents around the world and their brain health. For now, perhaps we should all follow the example of the Parisians and enjoy in moderation. Cheers for now!

 

Bibliography

Crego A, Rodriguez-HolguõÂn S, Parada M, Mota N, Corral M, Cadaveira F.(2009). Binge drinking affects attentional and visual working memory processing in young university students. Alcohol Clin Exp Res. 33(11):1870–9. 10.1111

Demossier, M. (2010). Wine Drinking Culture in France: A National Myth or a Modern Passion? (French and francophone studies) (p. 13). Retrieved from https://books.google.com.

Marie-Pierre Tavolacci, Eloïse Boerg, Laure Richard, Gilles Meyrignac, Pierre

Dechelotte, et al., (2016) Prevalence of binge drinking and associated behaviours among 3286 college students in France. BMC Public Health, BioMed Central, 16, pp.178.

Squeglia, L.M., Schweinsburg, A.D., Pulido, C. & Tapert, S.F. (2011) Adolescent Binge

Drinking Linked to Abnormal Spatial Working Memory Brain Activation: Differential Gender Effects. Alcoholism: Clinical and Experimental Research, 35, 1831-1841.

White, A. & Hingson, R. (2014) The burden of alcohol use: excessive alcohol consumption and related consequences among college students. Alcohol Res, 35, 201-218.

Image 1: from Demossier (2010) p. 10

Image 2: http://www.wikileaks.info/lifestyle/nightlife-in-paris/

Image 3: http://faculty.washington.edu/losterho/erp_tutorial.htm

Image 4: https://www.researchgate.net/publication/263156210_Nicotine_Impairs_Spatial_Working_Memory_while_Leaving_Spatial_Attention_Intact__Time_course_and_disruption/figures?lo=1&utm_source=google&utm_medium=organic

 

It’s Not Just a Phase, Mom- How Sad Music is More Enjoyable than Happy Music

In light of the recent music festival and the fact that music can be heard regularly throughout the Métro and streets of Paris, I decided to look into the effects of music on the brain. In my experience I’ve always found that, in a public setting such as the Métro, I prefer to hear people playing calming instrumental music, like an acoustic guitar, rather than an entire band playing an upbeat song. While this may just be based on personal opinion, I wanted to know if there was a neurobiological process that governed this reaction. Obviously, examining every sentiment or bias towards music is beyond the scope of one or two studies, so I refined my question: what brain processes drive us to form opinions of music that is perceptually happy or sad?

Figure 1: Map of all the Fête de la Musique major events in Paris- there’s music for all tastes!

My first inquiry led me to an article by Brattico et al. (2011) that aimed to show the difference in activity of certain brain regions from music that is happy or sad, and with or without lyrics. They hypothesized that songs with lyrics will activate the left fronto-temporal language network, while songs without lyrics would activate right-hemispheric brain structures. Also, they expected to observe activation of left-hemispheric auditory areas by happy music (which is richer in fast transitions) and of right-hemispheric areas by sad music (with slower “attacks” and tempos). They used fifteen subjects who were told to bring in 16 familiar music pieces: four sad and four happy pieces from favorite music, and four sad and four happy pieces from disliked or even hated music. The music, within the four categories, was then computer-analyzed to average the attack slope (sharpness of musical events, for example, most percussion would result in a high attack slope) and spectral centroid (brightness and frequency balance of the music, similar to timbre), as well as tempo and mode (major or minor chord quality) (Figure 2).

Figure 2: Differences of attacks slope, spectral centroid, tempo, and mode in the four music categories.

The subjects listened to 18 second excerpts of the music they brought while their brain activity was monitored. After the excerpts, they were asked if they liked or disliked the music, as well as if they thought the music was happy or sad. Their findings of the difference in activated areas between categories are shown in Figure 3. Although the researchers described in detail what each activated brain region meant in correlation with its usual information processing, I’ll only mention a few interesting points that relate to my original question:

  • Sad music induced activity in the right caudate head and the left thalamus. Interestingly, the left thalamus is one of only a few brain structures that is involved in processing sadness in faces, suggesting a link between emotions evoked by visual or auditory stimuli.
  • Also, sad music led to activity in both the subcortical stratial region, which is involved in judging musical and physical beauty.
  • Happy music without lyrics more strongly activated structures associated with perception and recognition of basic emotions, like the left anterior cingulate cortex and the right insula, than happy music with lyrics.
  • However, sad music led to wider brain activity during music with lyrics than without, such as emotion-related areas like the right claustrum and left medial frontal gyrus.

Figure 3: Differences in activation of brain regions due to music emotion and presence of lyrics. For example, “Lyrics > Instrumental” signifies the regions that were activated in lyrical music, but not in intrumental. ITG stands for inferior temporal gyrus, ACC stands for anterior cingulate cortex, Cau for caudate, Cun for cuneus, CG for cingulate gyrus, Dec for cerebellar declive, ITG stands for inferior temporal gyrus, Put for putamen, STG for superior temporal gyrus, TTG for transverse temporal gyrus, and Thal for thalamus.

Based off these results, the researchers concluded that instrumental music is efficient in conveying positive emotions, while sad emotions are reinforced when lyrics are present. They suggest that vocal cues in sad music activate deep emotion-related structures which produce mental associations with negative emotional experiences, as shown in activation of limbic and paralimbic regions. This activation causes people to have “moving” experiences.

Below are two pieces of music I think Brattico et al. would suggest have high emotional impact- a familiar sad song with vocals and a familiar instrumental happy song. How do they make you feel? (Songs are Hallelujah by Jeff Buckley and Canon in D by Pachelbel, I own no rights to these)

Overall, I thought the study provides a thorough analysis of the brain regions that are differentially activated during happy or sad music, and even considers the effect of lyrics. The only aspect of the experimental procedure that confused me was their decision to have the subjects bring in their own music. Although the researchers say that the subjects had similar familiarity with the music, there was probably some differing in familiarity throughout the categories. I, for one, would probably have a more difficult time finding four sad songs that I hate but know well, than I would in finding four happy songs that I like.

Something that I still didn’t understand fully was their mention of the underlying feelings of being “moved” from music. So, I looked at another article, this time by Vuoskoski and Eerola (2017), that examined the effect of perceptions of music, such as beauty, on this sentiment. They hypothesized that sadness in music has a positive association with beauty, and mediates the feeling of being moved, which in turn causes a sense of enjoyment or pleasure.

The experimental procedure consisted of having 19 music students listen to 27 short film excerpts. The participants then rated the perceived emotion of the music based on six scales: sad/melancholic, moving/touching, tender/warm, peaceful/relaxing, scary/distressing, and happy/joyful, as well as if they liked it or not. The correlation between the qualities is shown in Figure 4. As the table shows, beauty was shown to have a positive correlation with sadness and a high correlation with liking. Also, the perception of being moved was the most highly correlated with beauty and sadness. Overall, Vuoskoski and Eerola found that the indirect effect via movingness on liking was twice the magnitude of that via beauty, which suggests that perceived movingness acts as the largest link between sadness and liking. In other words, the sadder a song is, the more you will be “moved”, and the more you will enjoy it. It is important to point out that this is not saying that happy songs are unlikeable- there was still a positive correlation between happiness and liking, but it was slightly lower than that of sadness.

Figure 4: Correlation values between different emotional qualities of music and liking.

This study gives convincing, albeit initially difficult to understand, connections between sadness and enjoyment of music through the sentiment of “being moved”. The only downside of the study is that the participants were asked about how they thought the music sounded, not how it made them feel. Although it might only be a slight difference in wording, it could play a larger role in terms in relating the feelings to regional activation in the brain, like in the study by Brattico et al. However, by accepting that perception and feeling are inherently linked, we can conclude that the largest enjoyment can be obtained from sad music with vocals, as it strongly activates the regions of the brain that cause the listeners to be emotionally moved. I think an interesting future direction would be to see the effect of human interaction on enjoyment from sad music- I would assume that there would be less enjoyment out of listening to sad music in a group setting, as cultural norms would start to play a larger role.

Even though the findings indicate that sadness gives a higher level of enjoyment, I find it hard to believe that this would not differ between people. What do you think? Do you find that you have a more emotional or pleasurable experience when listening to sad music than happy music?

References:

Brattico E, Alluri V, Bogert B, Jacobsen T, Vartiainen N, Nieminen S, Mari Tervaniemi M (2011) A Functional MRI Study of Happy and Sad Emotions in Music with and without Lyrics. Frontiers in Psychology. 2:308.

Vuoskoski JK, Eerola T (2017) The Pleasure Evoked by Sad Music Is Mediated by Feelings of Being Moved. Frontiers in Psychology. 8:439.

Figure 1 was found through Creative Commons

Figure 2 and 3 were taken from the article by Brattico et al.

Figure 4 was taken from the article by Vuoskoski  and Eerola

Videos were taken from YouTube

Répétez-vous?

I knew from the minute I set foot into the French customs line at the Charles de Gaulle airport that perhaps I didn’t know French as well as I thought I did. Every conversation around me—except for the Americans’ I followed off the plane—sounded oddly like gibberish. In keeping with my nosy personality, I sidled a little closer to the French couple behind me to see if I could eavesdrop on a word or two—nada. One would think that five years of taking French classes would have gotten me a little farther than that.

Image Courtesy of Google Maps

I still remember my reaction in the first few minutes of French 201 at Emory. My professor greeted all the students in French when we walked in the door. Oh, that’s cute, I thought. But when 11:30 hit, class officially started, and she continued to speak in French, my mouth actually dropped open. How was I supposed to understand her? I could barely understand a word of spoken French. The nerve of my French professor to actually speak in French! Initially, the biggest thing on my mind was finding out a way to get the biggest bang for my buck in returning my newly purchased French textbooks.

Fortunately, a mix of procrastination in dropping the course and unyielding determination—a quitter I was not—led me to eventually decide to tough it out in French for the year. Good thing I did, because a few months later I would find myself in the largest French-speaking city in the world.

Setting foot in Paris a few weeks ago brought me right back to the feelings I felt the first day of French 201. As the weeks went by, I practiced, spoke to a few French natives, and most importantly, I listened. I started getting lost in the raw melodies of the French language—often I would find myself listening to the intonations of the speech rather than actually paying attention to what was said. I started comparing French to other languages, like English. Would a foreigner to the English language appreciate the melodies that are simply words to us? How does the brain process it? I know that there are some languages that have totally different basic sound units—can a person who is not native to the language even process those units? The budding neuroscientist in me had so many questions.

I looked up this super cool graphic from medical daily that basically told me that yes—language changes the way we think* For example, because there are more words for colors from dark to light blue in the Japanese language than in English, the Japanese perceive more colors than we do. Conversely, languages with fewer terms have the opposite effect—those native speakers perceive even less colors (Medical Daily). The ball doesn’t just stop at color perception—there are nearly infinite differences between languages that could change the way we think. Do these differences mean that the brain of one native language speaker is set up a little differently from the next? I wondered: Do differences in language between native speakers have any effect on the brain?

An article by Ge et al. (2015) asks how native speakers of different languages process that language—specifically Mandarin Chinese and English. Why did experimenters compare English with Chinese and not, say, the second best language on Earth—French? A part from English and Chinese being the two most widely used languages in the world, the Chinese language is a tonal language, meaning that the intonation used determines the meanings of the words. English, on the other hand, is atonal (hence the reason why high school geography teachers could get away with fully monotone class sessions). Researchers placed 30 native Chinese speakers and 26 native English speakers in fMRIs and used dynamic causal modeling (DCM)—which is essentially a way to construct a model on how brain regions interact. Our lovely subjects were presented with either intelligible or unintelligible speech in their native languages while being scanned, then data was compared between the two groups.

Classic language areas

Now, before we delve into the scintillating results of this study, let’s talk a little about how brain areas relating to language actually work. Most of language is processed in the left hemisphere of the brain. In this classic language area are structures like Broca’s area and Wernicke’s area, which are big names to the brain language nerds. Perhaps more relevant to this article is the pathway associated with the sound-meaning map, which assumes language-processing starts from the temporal lobe, goes to its anterior reaches, and ends up in the frontal lobe. In this paper, researchers think that this sound-meaning area will be more highly activated in native Chinese speakers, since their language relies so heavily on sounds and intonations for understanding speech.

Now for the exciting part: were the researchers right? They found that while the regions themselves that process speech are mostly the same across languages, the pathways through which these regions interact may be different. The brain areas commonly associated with language are the left posterior part of the superior temporal gyrus (pSTG), the anterior part of the superior temporal gyrus (aSTG), and the inferior frontal gyrus (IFG), which—for the purposes of this study—were named regions P, A, and F, respectively.

Essentially, data showed that when hearing intelligible speech, both the Chinese (tonal) and English (atonal) brain showed increased speech in the P to A areas—that’s shown by the green arrow on the first brain in the diagram below. Chinese speakers showed more activation than English speakers when listening to intelligible speech in both of the pathways coming out of the A area (red arrows in the middle brain). This may be due to further semantic processing that is needed for word identification in Chinese. This also happens to be one of the pathways for the sound-meaning map that we talked about before. So yes, the researchers were right in their hypothesis (big surprise)— the Chinese brain had more activation in this particular pathway than the English brain did. Finally, good ole’ English speakers showed more activation than Chinese when listening to intelligible speech in the P to F pathway (the red arrow on the final brain). This pathway is usually implicated in phonological speech processing (Obleser et al., 2007), where the first phonological features are usually enough to be able to identify words in atonal languages. Long story short, this data tells us that while there are common pathways used in understanding speech in both languages, some of the pathways between the brain regions are also different. To the big language nerds—and now to us—that’s pretty exciting stuff.

Figure 2A from Ge et al (2015)

 

What’s great about this paper is that it uses two languages that have really clear differences—tonal Chinese vs. atonal English. Scientific experiments are usually best with wide and clear-cut variables like those seen between English and Chinese, so the languages they tested for in this study were great. However, because of the way that this experiment was designed, we don’t know whether their main question—how is language processed in the brain by native speakers of a different language—really has anything to do with whether the subject was a native speaker or not. We don’t know if the pathway activation that we saw was due to a different general functioning of the brain in a given subject, or if it was due to the subject simply understanding a language that required certain pathways to be activated. In other words, is the difference in activated pathways due to the inherent way a native speaker’s brain works, or is it due to the pathways required to understand the language—regardless of the brain that’s doing the processing? In defense of the article, their question may not have been this complex. Maybe in the future, researchers could do a further experiment with native English speakers who also understood Chinese (or vice versa), and compare activated pathways when they heard intelligible Chinese to the pathways activated in a native Chinese speaker.

Either way, it’s definitely interesting to know that different languages require different brain pathways for processing. Maybe one day—preferably after an especially delicious Nutella crepe—the language pathways in my brain used for understanding French will become activated, and I can finally eavesdrop on all the airport conversations I want.

-Ngozi

 

 

*http://www.medicaldaily.com/pulse/how-learning-new-language-changes-your-brain-and-your-perception-362872

Image #2 from: thebrain.mcgill.ca

References

Crinion JT, et al. (2009) Neuroanatomical markers of speaking Chinese. Hum Brain Mapp 30(12):4108–4115.

Ge J, Peng G, Lyu B, Wang Y, Zhuo Y, Niu Z, Tan LH, Leff A, Gao J (2015) Cross-language differences in the brain network subserving intelligible speech. PNAS 112(10):2972-2977.

Obleser J, Wise RJ, Dresner MA, Scott SK (2007) Functional integration across brain regions improves speech perception under adverse listening conditions. J Neurosci 27(9):2283–2289.

 

 

 

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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

A Day Just for Music

Dear family and friends,

Imagine a day in Paris dedicated to music – voilà, Fête de la Musique!

My friends and I decided to first explore the music scene in the Saint Michel-Notre Dame area, one of our favorite parts of Paris (see map below). As soon as we emerged from the underground metro station near the Saint Michel Fountain, we heard a lively cacophony of sounds from every direction. Immediately, my appreciation for jazz music pulled me towards a jazzy trio on Rue Serpente. After they concluded their piece, I felt compelled to keep moving and enjoying as much music as possible. Further along, at the intersection of Rue Serpente with Rue Hautefeuille, we bumped into a crowd of spectators swaying to a soft rock band and our faces instantly brightened with auditory pleasure. Earlier in the day, I felt stressed by schoolwork and my upcoming departure from Paris, but I was beginning to notably relax upon joining the musical festivities.

Fete de la Musique Map

While I was absorbed in the drum rhythms of another music group – I even watched a dance-off between a young girl and a grown man! – I considered the ways in which music was positively impacting my mental state (see image below). But the neuroscientist in me also wondered, what happens at the neurobiological level?

danceoff                                                                        Dance-off

After some internet research, I chose a study by Sheikhi and Saboory examining the impact of musical stimuli on the rat brain, because the study was uniquely conducted during the fetal period. Isn’t that incredible? Previous studies have identified the connection between environmental factors and prenatal development, demonstrating how sensory and motor stimuli entering the central nervous system can lead to neuroplasticity changes in neurons (Mathies et al., 2013). Neuroplasticity refers to changes in neural pathways and synapses. Specifically, stimuli can cause an increase in synaptic connections in the brain (Pirulli et al., 2013). In the fetal brain, other studies have examined the fetal response to music (Gerhardt et al., 2000). In this particular study, Sheikhi and Saboory examined neuroplasticity and neuronal cell density in the parietal cortex (see image below) of the fetal rat brain that was exposed to music as part of a prenatal model.

As part of the methodology, the researchers utilized twelve female Wistar rats (see image below) and followed ethical guidelines established by the Medical Ethics Committee of Iran. (Ethics boards encourage researchers to use the lowest number of rats and cause the least amount of pain possible!) At twelve weeks, the researchers mated the female rats and then divided pregnant rats into a control group and a musical group. Thus, each group included six pregnant rats. Twice per day, from day 2-20 of gestation, researchers exposed the musical group to classical music. However, they did not expose the control group to music. Before labor could occur on the 21st day of gestation, the researchers anesthetized the pregnant rats and collected blood samples from them. Sheikhi and Saboory removed the fetuses and randomly chose one fetus from each mother for brain dissection. Then, the researchers horizontally sliced the parietal cortex and examined the slices via an electron microscope. Returning to the blood samples collected from the pregnant rats, Sheikhi and Saboory measured corticosterone (COS) levels in each blood sample. Corticosterone refers to a hormone secreted by the adrenal cortex in rodents (see image below). COS protects against stress, in a similar way to cortisol in humans.

Wistar rat                                                                        Wistar rat

parietal_lobe                        The parietal cortex is located in the yellow region of this brain.

rat body

                             The adrenal cortex is the outer part of the adrenal gland.

Sheikhi and Saboory found that control rats exhibited simpler and smoother cells, while the music-treated group exhibited a more complex cell membrane and cytoplasmic organelles, which are the specialized structures inside of cells. Alternatively, the intercellular space, or the space between cells, displayed a greater density of structures in music-treated rats than in control rats. To determine the effect of prenatal music on the density of parietal cortical cells, researchers counted the number of nuclei in one electron microscope field, since each cell should theoretically have one nucleus. As expected, researchers found a greater cell density in the parietal cortex of music-treated rats than in control rats. Additionally, prenatal music helped to reduce COS blood levels in pregnant rats. Aha! I bet that a decrease in my cortisol levels is one of the reasons why I felt so relaxed during Fête de la Musique.

I believe the prenatal music model is a unique strength in study design and the findings can be related to an intra-uterine musical effect. However, I would like to offer a few of my own criticisms and suggestions for future experiments. According to the methodology, researchers only collected blood samples on the 21st day of gestation, and then claimed to see a reduction in COS blood levels. However, in order to draw comparisons, the researchers should have collected at least one other blood sample on the 1st day of gestation. Preferably, Sheikhi and Saboory should also have drawn blood from the pregnant rats at various, controlled time points throughout the experiment for stronger comparisons. In this research study, researchers exposed pregnant rats to only classical music, but I wonder if results would change with exposure to different types of music, such as jazz or soft rock. In a future experiment, Sheikhi and Saboory could also test the effect of music on rat infants immediately following birth. Additionally, the researchers only examined the fetal parietal cortex, but should examine other cortical areas as well.

– Beatrice

References

Gerhardt KJ, Abrams RM (2000) The Fetus Fetal Exposures to Sound and Vibroacoustic Stimulation. Journal of Perinatology 20:S20-S29 Available at: http://www.ncbi.nlm.nih.gov/pubmed/11190697 [Accessed June 22, 2015].

Matthies U, Balog J, Lehmann K (2013) Temporally coherent visual stimuli boost ocular dominance plasticity. J Neurosci 33:11774–11778 Available at: http://www.ncbi.nlm.nih.gov/pubmed/23864666 [Accessed June 22, 2015].

Pirulli C, Fertonani A, Miniussi C (2013) The role of timing in the induction of neuromodulation in perceptual learning by transcranial electric stimulation. Brain Stimul 6:683–689 Available at: http://www.ncbi.nlm.nih.gov/pubmed/23369505 [Accessed June 22, 2015].

Sheikhi S, Ph D, Saboory E, Ph D (2015) Neuroplasticity Changes of Rat Brain by Musical Stimuli during Fetal Period. 16:448–455 [Accessed June 22, 2015].

*I photographed the rock band and drum group, and found the other images through Google Maps and Images.

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.

Screen Shot 2015-06-22 at 1.43.12 PM

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