Author Archives: Alicia Brown

“I put my heart and soul into my work, and have lost my mind in the process.”  This quote, attributed to the painter Vincent van Gogh embodies both the beauty displayed in his paintings and the presumed mental illness he suffered during his life.  While the iconic swirls and visual auras of the former have fascinated museum-goers and art collectors alike, the enigmatic nature of the latter has also stupefied art historians and other curious academics

The subject of mental health is quite prevalent in my life.  Both of my parents are mental health professionals who have dealt with severely mentally ill patients, with conditions similar to that of van Gogh, and their passion for the human mind has inspired me to want to pursue a career in the field.  Thus, it was of great excitement to me when, one day, in class we discussed the apparent severe mental illness of Vincent van Gogh.  We were able to further immerse ourselves into his life when our class took a trip to the south of France and visited the town of Arles, where van Gogh’s infamous ear incident took place.  These experiences encouraged me to think about what illness actually ailed the iconic man.

A few classmates and I at a recreation of the cafe Vincent van Gogh was known to frequent in Arles

While it is impossible to retroactively diagnose someone with a mental illness, it is a popular opinion among scholars that Vincent van Gogh suffered from manic depression, or bipolar disorder, as it is known today (Wolf, 2001).  Much of the evidence for this possible diagnosis comes via letters between Vincent van Gogh, his brother, Theo, and his sister, Wilhelmina (Blumner, 2002).  In a letter to his sister, Theo described Vincent as seeming, “as if he were two persons … with arguments on both sides” (Blumner, 2002).  Later, Vincent complained to his brother about his “heightened emotionality” and increasing reliance on alcohol to dull “the storm within” (Blumner, 2002).  Vincent also noted “horrible fits of anxiety” and attacks of “melancholy and atrocious remorse” which would be followed by “enthusiasm or madness or prophecy, like a Greek oracle on the tripod,” in letters to his brother (Blumner, 2002).  The mental turmoil that Vincent noted in his letters culminated in an acute psychotic episode in which he sliced off a section of his left ear lobe and presented the piece to a prostitute (Blumner, 2002).  During this episode, van Gogh experienced hallucinations and delusions, which required a multi-day stay in solitary confinement (Blumner, 2002).

Self-Portrait with Bandaged Ear- Vincent van Gogh: This work by van Gogh was painted shortly after the severed part of his left ear during a psychotic episode

Both van Gogh’s description of his condition in notes to his brother and his subsequent psychotic episode are potentially indicative of bipolar disorder.  According to the National Institute of Mental Health bipolar disorder is characterized by “periods of unusually intense emotion” (NIMH).  These periods of emotion usually oscillate between manic episodes and depressive episodes.  Van Gogh’s description of periods of increased enthusiasm is consistent with mania, while his feelings of extreme melancholy are consistent with depression.  Additionally, bipolar patients often present with other illnesses such as anxiety disorder and substance abuse (NIMH).  Van Gogh experienced extreme levels of anxiety and he was a known to frequently have “a glass too much” of absinthe (Blumner, 2002).  Occasionally, patients experiencing severe bipolar disorder can exhibit psychotic symptoms, including hallucinations or delusions, as van Gogh did during the incident in which he severed his ear (NIMH).

Another key facet of bipolar disorder, as noted by the National Institute of Mental Health is its genetic risk factor (NIMH).  In class, we discussed the prevalence of mental illnesses, specifically schizophrenia, depression, and anxiety, in the van Gogh family.  There appears to be a strong presence of mental illness in the van Gogh family; however, there are no reported cases of bipolar disorder.  How then, could Vincent van Gogh appear to have suffered from a disease that no one else in his family had?

While there are no explicit cases of bipolar disorder in his family, there is a strong genetic link between bipolar disorder and schizophrenia; in fact, heritability estimates of the disorders are estimated to between 60 and 80 percent (Nöthen et al., 2010).  In 2017, the Bipolar Disorder and Schizophrenia Working Group of the Psychiatric Genomics Consortium published a large-scale investigation into the genetic markers of bipolar disorder and schizophrenia.  This study, which examined genomic data from over 53,000 individuals with either bipolar disorder or schizophrenia, identified 114 locations in the human genome as risk factors for both schizophrenia and bipolar disorder (Ruderfer et al., 2017).

In addition to the genetic risk factors identified in both bipolar and schizophrenic patients, the study produced another, extremely novel, finding.  Instead of comparing only patients with bipolar disorder to patients with schizophrenia, the researchers compared data from schizophrenic patients to two subpopulations of bipolar patients: those that presented psychotic symptoms and those that did not (Ruderfer et al., 2017).  Through this comparison, the researchers concluded that bipolar patients with psychosis are significantly more like to possess genetic risk factors associated with schizophrenia than bipolar patients without psychosis (Ruderfer, 2018).  This genetic overlap between bipolar disorder patients with psychosis and schizophrenic patients could serve to provide the seemingly missing link in the mental illnesses attributed to the van Gogh family.

To me, it is a stark, yet beautiful, reality that such a creative and influential person as Vincent van Gogh potentially suffered from a disease a debilitating as bipolar disorder.  I think that my experience in both traveling to Arles and researching van Gogh’s mental health gave me a greater appreciation of the fact that people’s illnesses do not need to define them.  The human brain, in all its diversity, is capable of creating masterworks, even in the most unlikely of places.

References

Blumer, D. (2002). The Illness of Vincent van Gogh. American Journal of Psychiatry, 159(4), 519-526. doi:10.1176/appi.ajp.159.4.519

NIMH » Bipolar Disorder. (n.d.). Retrieved from https://www.nimh.nih.gov/health/topics/bipolar-disorder/index.shtml

Ruderfer, D., Sklar, P., & Kendler, K. (2017). Genomic dissection of bipolar disorder and schizophrenia including 28 subphenotypes. doi:10.1101/173435

Ruderfer, D. (2018, October 17). A Revealing Genetic Comparison of Schizophrenia and Bipolar Disorder. Retrieved from https://www.bbrfoundation.org/content/revealing-genetic-comparison-schizophrenia-and-bipolar-disorder

Wolf, P. (2001). Creativity and chronic disease Vincent van Gogh (1853-1890). Western Journal of Medicine, 175(5), 348-348. doi:10.1136/ewjm.175.5.348

It didn’t take long to realize why Paris is called the city of love. During our first week here, some of the guys and I enjoyed a romantic evening stroll to the Wall of Love. This wall (pictured below) is a forty square meter canvas covered with the words “I Love You” in over 300 languages. The thought that love is a universal language is portrayed here, not only due to the seemingly infinite phrases, but because of the range of people there too. Couples, friends, and families from all over the world were visiting; a broad range of love could be observed. This got me thinking about Paris. What makes it such a magical place, renowned for love?

A romantic afternoon

First, I wanted to figure out what goes on in the brain during these feelings of love. Research has shown that certain neurotransmitters are involved in love, such as dopamine, oxytocin, and serotonin. Firstly, people in love show low levels of serotonin in the brain, which is also known as the satiation chemical (Zeki, 2007). The obsessive component of new love can thus be attributed to the dissatisfaction one may feel due to the brain’s lowered levels of serotonin. It leaves us always wanting more.

Furthermore, this study also shows that similarity and familiarity with someone at the start of a relationship can counteract the drop in serotonin levels usually observed with love. Thus, this can prevent people from falling in love (Zeki, 2007). However, in later stages of relationships, similarity and familiarity have actually been shown to boost the strength and duration of a relationship. This is linked with increased levels of oxytocin and vasopressin during this stage of a relationship, which are chemicals believed to be involved in attachment (Zeki, 2007).

Studies were also done on dopamine, the neurotransmitter believed to be involved in reward and motivation. People who were intensely in love for 1 to 17 months were first shown a picture of their loved one and then a picture of a familiar individual. When looking at the photo of the loved one, there was higher activation of the right ventral tegmental area, right postero-dorsal body, and the medial caudate nucleus, all of which are areas associated with dopamine (Aron et al., 2005). Thus, when you are in love the increased levels of dopamine may be involved in the rewarding nature of the loved one’s presence.

A 2017 study looked closer into the relationship between love and addiction, as the same chemicals have been shown to be involved in each. This study looked at the future potential to treat love addiction if it were to become a harmful condition (basically, love is a powerful thing). They found, for example, that oxytocin antagonists could be used in an individual to reduce the reward felt from being close to another person (Earp et al., 2017). Could there soon be a way to get rid of your obsessive ex?

The location of the Love Wall

Now that we know the underlying chemicals behind the feeling of love, what is it about Paris that brings them out of us? A 1974 study found that men were more likely to experience feelings of love towards a female interviewer when the interview took place in an anxiety and adrenaline-provoking location, such as a suspension bridge, rather than in calm locations (Dutton and Aron, 1974). Perhaps Paris’ chic people, luminescent nights, quaint cafes, and the feeling of being in a new place create an adrenaline and anxiety-filled environment in which we are more susceptible to these chemical changes in our brains, thus helping Paris to its title as The City of Love.

Sources

Aron A, Fisher H, Mashek DJ, Strong G, Haifang Li H, Brown LL. (2005) Reward, Motivation, and Emotion Systems Associated With Early-Stage Intense Romantic Love, Journal of Neurophysiology 94, 1: 327-337.

Dutton, D.G., & Aron, A.P. (1974). Some Evidence for Heightened Sexual Attraction Under Conditions of High Anxiety, Journal of Personality and Social Psychology, 30 (4), 510-517.

Earp, B., Wudarczyk, O., Foddy, B., Savulescu, J., (2017). Addicted to Love. What is Love Addicton and When Should it be Treated?, Philos. Psychiatr. Psychol., 24(1): 77-92

Zeki, S. (2007). The Neurobiology of Love, FEBS Letters 581, 14: 2575–2579.

Paris is truly one of the cultural centers of the world.  Packed into its city limits are monuments galore, which tourists flock to in droves from all over the world.  Crowded around such landmarks as the Louvre, Arc de Triomphe, and the Eiffel Tower, tourists stand amazed by the beauty and historical significance that is displayed.  Within these masses, tourists constantly reach into their pockets to snap a picture with their cell phone, parents look for their child that has seemingly disappeared into the crowd, and overzealous couples get far too intimate in front thousands of people.  After all, what’s more romantic than French kissing in Paris while a 6-year-old boy and his family watch?  Accompanying the interpersonal chaos, are the calls of street vendors selling “Beer, Beer, Wine, Champagne!” and “Five miniature Eiffel Towers for One Euro!” and the smells of crepes cooking in small stalls nearby.

Classmates in front of the Eiffel Tower not attending to their belongings!

This symphony of sensation represents what many people, from newlyweds to elderly tour groups, deem to be heaven.  However, these sites are heaven for another group of people.  A group of people tourists are less than keen on encountering: pickpockets.

Despite their conniving practices, pickpockets actually rely on several fundamental principles of neuroscience to execute their forays into hapless tourists’ pockets and purses.  Chief among these principles is selective attention, or one’s ability to focus their awareness on a single stimulus, thought, or action, while simultaneously ignoring irrelevant stimuli, thoughts and actions (Gazzaniga et al., 2013).  While the brain’s ability to prioritize what it attends to is appreciated as one tries to take in the beauty of the Eiffel Tower while simultaneously ignoring THAT couple. This prioritization can also be a detriment.  For instance, as a person concentrates their attention on the Eiffel Tower, their attention is no longer on their back pocket.  This phenomenon is called inattentional blindness and can be summarized as the brain’s propensity to miss additional information when it focuses on an object (Zhang et al., 2018).  This disparity in attention provides pickpockets with the perfect window to abscond with your belongings.

Another aspect of inattentional blindness that should worry tourists is its correlation with perceptual load (Remington et al., 2014).  Perceptual load refers to the amount of task-relevant information in a given task (Remington et al., 2014).  For instance, in tasks with high perceptual loads, such as gazing at the Eiffel Tower while also navigating through a crowded and noisy environment, there is a higher occurrence of inattentional blindness than when completing with lower perceptual loads (Remington et al., 2014). The Remington research group conducted a study across age groups ranging from 7-8-year-olds to adults in which they introduced irrelevant visual stimuli during a visual memory task of varying perceptual loads.  Across most age groups, increasing the perceptual load of a task resulted in a decrease in the ability to report irrelevant visual stimuli (Remington et al., 2014).  These disparities were especially notable in adolescents, as most children noticed irrelevant stimuli 30% less while experiencing higher perceptual load (Remington et al., 2014).  Interestingly, 9-10-year-olds displayed minimal inattentional blindness during higher perceptual loads (Remington et al., 2014).  Comically, the researchers dispelled the notion that 9-10-year-olds are especially adept at paying attention by saying that – shockingly – the 9-10-year-olds were never paying particularly astute attention, even in the low perceptual load task (Remington et al., 2014).  So, moms, don’t trust your nine-year-old with protecting your Louis Vuitton bag from pickpockets.

A graph demonstrating the differences in the percent of irrelevant objects noticed during an intermediate perceptual load and a low perceptual load scenario (Remington et al., 2014).

However, adult brains are not infallible when it comes to attending to information from multiple sources.  In 2018, Hui Zhang’s research group used a similar task to that used by Remington et al. to investigate whether there were significant differences between inattentional blindness in children and adults.  In their research, over half of the participants, regardless of age, exhibited inattentional blindness (Zhang et al., 2018).  Additionally, their research showed that there were no significant differences between levels of inattentional blindness in adults or children.

Ultimately, the research studies of the Remington and Zhang groups complement each other nicely in that they each elucidate different factors of an individual’s susceptibility to inattentional blindness.  I think that tourists should take interest in the findings that highly stimulating environments, such as Paris, increase their propensity to overlook peripheral information, and that everyone, even adults, needs to be cognizant of their surroundings at all times.

Now that I mention it, I seem to be short about 300 Euros right now … time to go file a police report!

References

Gazzaniga, M., & Ivry, R. (2013). Cognitive Neuroscience: The Biology of the Mind: Fourth International Student Edition. W.W.Norton.

Remington, A., Cartwright-Finch, U., & Lavie, N. (2014). I can see clearly now: the effects of age and perceptual load on inattentional blindness. Frontiers in Human Neuroscience, 8. doi:10.3389/fnhum.2014.00229

Zhang, H., Yan, C., Zhang, X., & Fang, J. (2018). Sustained Inattentional Blindness Does Not Always Decrease With Age. Frontiers in Psychology, 9. doi:10.3389/fpsyg.2018.01390

The room is packed. Everywhere I looked I could see drinks, banter, and tension filling the room around us. And this event had every right to be packed. This was the Champions League final, the biggest event of European soccer. While European television does a good job keeping most of the ads at the minimum that night, one ad continued to repeat throughout halftime, a simple ad covering a sports gambling service.

One of the largest online sports gambling sites within the EU

While not a complete stranger to the world of gambling, seeing how pronounced these types of services were advertised towards the general public, I opened towards the true prominence of gambling within our society. From small dollar wagers with friends to the million dollar sports matches, gambling has become pervasive within Western culture. Though the prevalence of this activity has made it easy for us to accept it as simply another aspect of the culture surrounding us, it is important to understand that when left unchecked this can easily snowball into something more.

A study conducted in 2012 discovered that chronic gamblers have similar hypoactivity in the dorsomedial prefrontal cortex to those of chronic smokers (De Ruiler, 2012). As the dorsomedial prefrontal cortex plays an important role in inhibiting our individual actions so that we don’t make any rash decisions when this particular area shows lesser levels of activation it prevents us from stopping ourselves from making impulsive decisions (Modirrousta, 2008). As such, the more we find ourselves gambling, the easier it is for us to become addicted to it since our brain is literally not telling us to stop ourselves. But not only does our brain not tell us to stop with this particular behavior, but it also activates to push us to gamble even more.

A recent study published by Limbrick-Oldfield set out to investigate as to what underlies our desire for continual gamblers to seek out gambling. After cueing the subjects that had chronic gambling problems with images related to gambling, they observed the brain activity of these subjects through functional magnetic resonance imaging (fMRI) tests. When looking at the results of the study, Limbrick-Oldfield found that when the gambling disorder subjects were shown gambling related cues, there was a significant increase in the activity of the left insula (Limbrick-Oldfield et. al, 2017). Prior research has shown that the insula plays a critical role in subjective feeling (Uddin, 2017). So by showing greater activation of the insula within these brain studies, Limbrick-Oldfield was able to show how his subjects yielded a greater emotional connection whenever they are shown cues of gambling. And it is with this greater emotional connection within these subjects that pushing gambling addicts to continue with their addiction.

The insula is located on the lateral side of the brain. It plays a significant role in our subjective emotional processing.

So the question remains, why do we find ourselves gambling in the first place? And the scientific answer to that question is actually very simple because it’s really fun. However, while you expect the fun of gambling to exist in the idea of winning big bucks, scientific evidence actually seems to point to the contrary.

In 2013, Patrick Anselme and Mike J.F. Robinson set out to understand exactly what seemed to motivate individuals to continually pursue gambling. After examining the dopamine release within the ventral striatum of gambling addicts who gambled, Anselme and Robinson found that the subjects had a greater amount of dopamine release whenever they lost money compared to when they won money (Anselme and Robinson, 2013). This idea plays along with the idea of “near misses”, stating that whenever you don’t win, the brain activates the reward system to enhance your motivation to keep gambling (Kassinove et.al, 2001). While this study does a clear job in underlying the major reward system within those who contain gambling addictions, one weakness is that it does not take into consideration whether this reward system pathway pertains to those of first-time gamblers. However, despite this limitation, the paper still offers valuable insight into the cycle of addiction that many continual gamblers fall into.

While understanding of the underlying influences beneath gambling addiction offers great insight towards the neural mechanisms that underlie the development of addiction as a whole, it still circumvents the issue that breaking these kinds of addictions are extremely difficult. Things like alcohol and gambling have long since part of both ours and Parisian culture for a long time coming and breaking that underlying development will go beyond what underlies our own culture.

So what is the main lesson that should be taken away from this? Well, for me, I would say to place your bets wisely, because no matter what you bet, the odds are never in your favor.

References:

Anselme, P., & Robinson, M. J. (2013). What motivates gambling behavior? Insight into dopamine’s role. Frontiers in behavioral neuroscience, 7, 182.

De Ruiter MB, Oosterlaan J, Veltman DJ, van den Brink W, Goudriaan AE. Similar hyporesponsiveness of the dorsomedial prefrontal cortex in problem gamblers and heavy smokers during an inhibitory control task. Drug Alcohol Depend. (2012)

E H Limbrick-Oldfield, I Mick, R E Cocks, J McGonigle, S P Sharman, A P Goldstone, P R A Stokes, A Waldman, D Erritzoe, H Bowden-Jones, D Nutt, A Lingford-Hughes & L Clark. Neural substrates of cue reactivity and craving in gambling disorder. Translational Psychiatry, 7 (2017)

Kassinove J. I., Schare M. L. (2001). Effects of the “near miss” and the “big win” on persistence at slot machine gambling. Psychol. Addict. Behav. 15, 155–158

Modirrousta, L.K. Fellows Dorsal medial prefrontal cortex plays a necessary role in rapid error prediction in humans J. Neurosci., 28 (2008), pp. 14000-14005

Uddin, L. Q., Nomi, J. S., Hébert-Seropian, B., Ghaziri, J., & Boucher, O. (2017). Structure and Function of the Human Insula. Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society, 34(4), 300–306.

https://en.wikipedia.org/wiki/Bet365.jpg

https://i0.wp.com/neurosciencenews.com/files/2017/01/nucleus-accembens-gambling-addiction-public-neurosciencnews.jpg

Last week I had the pleasure to watch people expressively jump, fall, run, and spin, all to the beat of music. Where could I see this moving art in the city of lights? The Palais Garnier hosts variety of shows including opera, concert, and, in my case, a ballet. As a person who can’t walk across a flat surface without tripping, I was amazed to see the unfathomable poise the dancers had in their movement. They could perfectly match complex poses and key beats of the music with a grace unfounded in the dancing my friends and I did in the Latin District discotheques. Nevertheless, over the next week I discovered whether you have the grace of a ballerina, a mosh pit, or an audience member during Fête de la Musique, all of our brains possess circuitry that enables our bodies to “move to the music.”

Four photos from the performance I attended: Bertaud / Bouché / Paul / Valastro at Palais Garnier. Taken from https://www.operadeparis.fr/en/season-16-17/ballet/bertaud-bouche-paul-valastro.

What came first: dance or music? A popular hypothesis addressing this “chicken or the egg” question promotes dance preceded music as dance is an application of motoric abilities essential for survival in most animals (Dean, Byron, and Bailes 2009). However, as music promotes reproductive success and enrichment of cultural capital, the two probably had a mutual factor encouraging their coevolution: rhythm. Rhythm perception has been consistently traced to brain areas such as the premotor and supplementary motor areas and the basal ganglia. Damage to these areas has caused timing issues (Grahn and Brett 2007). For instance, patients that have Parkinson’s Disease, a disorder affecting the basal ganglia, struggle with walking at a rhythmic pace (Grahn and Brett 2007).

Taken from http://antranik.org/wp-content/uploads/2011/11/basal-ganglia-caudate-nucleus-and-putamen-and-thalamus-and-tail-of-caudate-nucleus.jpg

Supplementary Motor Area. Taken from https://static1.squarespace.com/static/52ec8c1ae4b047ccc14d6f29/t/576f2964b3db2bd35f648444/1490438406965/supplementary-motor-area.jpg

Recent research has better elucidated how our bodies perceive and synchronously move with different rhythms. A typical lab test for rhythm involves tapping alongside a beat that may fluctuate in speed. A 2016 study used this set up as participants sat in a dMRI, an MRI imaging machine that specifically tracks water movement in your brain. dMRI is a useful technique for visualizing the highways that carry information across your brain, called white matter tracts. The goal of the study was to investigate what “highways” are used most when syncing movements to a beat. During the task, they averaged the asynchrony between the beat and the participant’s tapping as well as how long it took the participant to adjust when the beat became faster or slower. The imaging system tracked increased water flow to particular brain regions, thus implying more activity along that highway when conducting the task.

Typical DTI image showing tracts of brain that send information to other brain areas. Taken from https://www.healthcare.siemens.nl/magnetic-resonance-imaging/options-and-upgrades/clinical-applications/syngo-resolve.

The study found syncing movements to the beat lead to more activity in the frontal area of the left arcuate fasiculus (Blecher, Tal, and Ben-Sachar 2015). As the arcuate fasiculus is an important connection highway between your main auditory perception area and premotor areas, it is no wonder stronger connections between these two areas promote better synchronization. In the context of the ballerinas at Palais Garnier, strong connections along the arcuate fasiculus are necessary for performing jumps and plies on the beat.

Correlational image of left arcuate fasiculus activation with mean asynchrony (Blecher, Tal, and Ben-Sachar 2015).

Arcuate Fasiculus. Taken from https://clinicalgate.com/wp-content/uploads/2015/03/B9780702037382000322_f032-001-9780702037382.jpg

The study also suggests people who are consistently better staying on beat have more activation along their temporal callosal segment(Blecher, Tal, and Ben-Sachar 2015). Callosal segments are highways known to connect the right and left sides of your brain. If we were to image a ballet dancer’s brain to mine, we would likely find stronger connections along the temporal callosal segment in the graceful ballerina than the clumsy college student. But what happens when the music becomes faster mid-performance? In this case, the study suggests our brains adjust to the new time via activation of the precentral callosal segment, another right-left brain highway by the motor regions of the brain (Blecher, Tal, and Ben-Sachar 2015). Overall, this research paper concluded highways on your left side of the brain connecting your auditory and motor areas and particularly activated when predicting and comparing auditory inputs and motor commands. Additionally, they concluded motor and premotor highways, which join the left and right side of brain, particularly activates when adjusting to a beat change(Blecher, Tal, and Ben-Sachar 2015).

dMRI image of participants brain. Precentral callosal segment shown in pink along side graph reflecting correlation between activation of segment with resynchronization time. (Blecher, Tal, and Ben-Sachar 2015).

Precentral gyrus where the pre central callosal segment connects the two hemispheres of the brain. Taken from https://www.kenhub.com/en/atlas/gyrus-precentralis

While this paper explains how we perceive and adjust to music beat, I would love to see more studies that particularly investigated rhythm changes in music. Jazz, for example, has a swing rhythm that doesn’t necessarily stay to one beat pace the whole song. I am curious if some music is easier to sync to your movements to than others. While I am pretty good at dancing on beat to a typical pop song, other genres of music like heavy metal may be more difficult to dance to because of the rhythmic beat inherent to the genre. Future experiments could possibly compare listeners with artists who specifically play that genre as well as artists who play a separate genre of music. I would expect artists of that genre would have stronger brain activation among rhythm-perception pathways when listening to their own music compared to artists who play a different genre or an average listener. Future experiments such as that one may better elucidate my understanding of why humans enjoy coordinating our bodies alongside a great song.

Bibliography

Blecher T, Tal I, Ben-Sachar M (2015). White matter microstructural properties correlate with sensorimotor synchronization abilities. NeuroImage 138:1-12

Grahn JA and Brett M (2007) Rhythm and beat perception in motor areas of the brain. Journ Cog Neurosci 19 (5): 893-906

Dean RT, Byron T, Bailes FR (2009). The pulse of symmetry: On the possible co-evolution of rhythm in music and dance. Musicae Scientiae 341-367.

If you travel with me long enough, you’ll find out I’m amazing at U-turns. This random talent has been continually cultivated by my terrible sense of direction, a condition that, whether walking, driving, or exploring, is beyond the help of Google Maps. Naturally, I was wary of coming to Europe out of anxiety of getting lost. Sure enough, during this Paris program and my cliché Euro-backpacking trip, getting lost down strange streets and roads was inevitable. However, all things considered I’ve been impressed how easily I can navigate my way to class or tourist attractions. I’ve even found myself guiding my friends when going to particular destinations. What about Europe makes my sense of direction sharper? This question motivated my investigation into the neurobiological pathways that modulate spatial navigation.

Taken from http://favim.com/road+sign/.

In the 1970’s a groundbreaking discovery in rats started detailed neurobiology research on how we know where we are. Neurons in the hippocampus and parahippocampus (brain location shown below) increase their firing rates when rats moves through specific regions of their environment, therefore creating a mental map (Ekstrom et al., 2003).

Taken from http://www.bristol.ac.uk/synaptic/pathways/

Figure from Ekstrom et al. (2003) showing images from the virtual reality participants navigated

Human experiments have found that neurons known as parahippocampal place cells fire when recognizing landmarks and passively exploring environments (Maguire, Burgess, and O’Keefe, 1999). Many navigational studies of recent decades image brains via fMRI or record neuron firings while participants move in virtual environments. For example, in a 2003 study participants drove a virtual taxi, picking up and dropping off customers at various locations around the virtual town. Both brain regions possessed “goal cells” that fired more if the participant succeeded in one of the experiment’s tasks. They found the hippocampus primarily activated to specific spatial locations while the parahippocampus fired when viewing a landmarks (Ekstrom et al., 2003). Tourism centers obviously understand the importance of landmark recognition when getting around, as most maps for Paris contain pronounced images of popular landmarks beside the street name. Our dependence on landmarks, however, can vary. One review referenced a study stating women rely more on landmarks than men as men also incorporate more global views into their mental maps (Maguire, Burgess, and O’Keefe, 1999).

Map of Paris with landmarks emphasized. Taken from http://parismap360.com/paris-tourist-map#.WT241KtLlSU

What does this navigational model mean when I’m trying to find the Eiffel Tower? My parahippocampus registers coarse spatial features, such as the metro station sign or the Eiffel Tower itself, while my hippocampus combines contextual visual and spatial features to form a mental map. Should I make the trek back to that location the next day with my friends, the same cells that encoded those features will fire again, reinforcing my overall sense of direction.

Taken from https://www.linkparis.com/paris-metro-map.htm

As I discussed my improved sense of direction with a friend, she posited that maybe this change was simply due to increased attention to my surroundings. A 2004 paper particularly backed her claim. Spatial tasks with mice found that long term firing stability of parahippocampal place cells was significantly increased with enhanced attention and context relevance (Kentros et al., 2004). Attention’s influences on navigation probably modulate neuron firing by promoting long term information encoding instead of short-term storage. Therefore, because I’m motivated to get back to my dormitory after exploring, I pay more attention, which in turn encodes landmarks along my walking route as memory traces. According to this mouse model, several hours can go by and I can still make it back to Cité Universitaire without getting lost.

In contrast to this idea, a human experiment published this year found innate sense of direction is unaffected by conscious attention (Burte and Montello, 2017). Participants who had various levels of self-assessed sense of direction navigated an unfamiliar neighborhood under a condition of intentional attention or incidental learning. The results found intentional attention participants did not learn the route any better than those of incidental learning, concluding sense of direction is applied without internal application. However, this study recognized their experimental design did not exactly follow models of other human studies that have promoted attention modulation when navigating.

While enhanced attention is a likely candidate for my newly gained sense of direction, more research is necessary before I have a sound explanation. In the meantime, however, I plan to enjoy exploring Paris with my friends using faster routes and, hopefully, fewer U-turns.

NBB 2017 Summer Program at the Eiffel Tower!

Bibliography:

Burte H, Montello DR (2017) How sense-of-direction and learning intentionality relate to spatial knowledge acquisition in the environment. Cog. Research: Principles and Implications 2:18.

Ekstrom AD, Kahana MJ, Caplan JB, Fields TA, Isham EA, Newman EL, Itzhak F (2003) Cellular networks underlying human navigation. Nature 425:184-187.

Kentros CG, Agnihotri NT, Streater S, Hawkins RD, Kandel ER (2004) Increased attention to spatial context increases both place field stability and spatial memory. Cell 42:283-295.

Maguire EA, Burgess N, O’Keefe J (1999) Human spatial navigation: cognitive maps, sexual dimorphism, and neural substrates. Current Opinion in Neurobiology 9:2:171-177.