Synthetic Synesthesia??

Over the course of the past five weeks in Paris, we’ve had countless unforgettable experiences. These experiences have provided a variety of sensations. Whether it be hearing the stadium roar as the US women score another goal, tasting a range of wines in Provence, or viewing the perfect blend of colors in Monet’s paintings, our sensory systems have definitely been active, processing and responding to unique, memorable stimuli. However, our discussion of synesthesia in class this past week led me to wonder how different these experiences all may have been for those lucky enough to be synesthetic. 

What someone with synesthesia may see when listening to music (looks like the lights at the Philharmonic)

Synesthesia is a genetic condition in which one sense is combined with one or more others (Watson et al., 2014). For example, a synesthetic person may “hear colors” or “see smells”. Synesthesia affects people in various unique ways. A video we watched in class attempted to recreate one synesthetic’s experience, in which she saw certain colors pop up in the corner of her vision when she played certain musical notes on the violin. Based off the video’s portrayal, synesthesia seemed like a beautiful condition to have. I started to wonder how life would be different if I could combine my senses to create new forms of perception, especially thinking about all the highly stimulating sensory experiences we’d had during the trip. Over the past two weeks, there were two more excursions that really got me thinking about how different they may have been with synesthesia. First, we attended an exhibit at the Paris philharmonic called “From Kraftwerk to Daft Punk”. This was a modern art exhibit which contained combinations of electronic music, dancing LED lights, and cinematic videos. There was a large structure in the middle of the exhibit in which a bunch of poles were lighting up in different colors. Watching these lights move, along with the music playing, made this feel like a synesthetic experience. It was as though the lights were dancing along with the beat of the song. During our last week here, we had another unique sensory experience when we visited Monet’s garden. The scent of nature along with the sound of birds chirping and the large spectrum of colors seen had me thinking about synesthesia again. Could this combination of senses be similar to how synesthetic individuals experience everyday life? 

Taking in the garden

Smelling flowers for the full Monet experience

With all this curiosity, I decided to look into ways to experience synesthesia as a non-synesthetic. Unsurprisingly, the only reported ways of artificially inducing synesthesia involve the use of illegal substances. The most successful drugs in achieving this effect are psychoactive agents such as LSD (acid) and psilocybin (mushrooms) (Luke and Terhune, 2013), which are proposed to work by activating serotonin receptors in our brains (Daniel and Haberman, 2017). 

There have only been four controlled studies done on the effects of these drugs to induce synesthesia, all occurring between 1933 and 1966, but they all have been successful in creating synesthetic experiences in humans (Luke and Terhune, 2013). In one of these studies, from 1963, participants were given a light to moderate dose of either LSD or psilocybin. Additionally, they were played 16 different tones of sound before and after drug consumption. These patients reported experiencing more colors and visual effects (brightening of the visual field, disruption of visual patterns, creation of new visual patterns) when they were played the auditory tones while under the influence of the drugs compared to before being administered the compounds (Hartman and Hollister, 1963). These findings suggest that psychedelic substances can create sensual pairings, in this case auditory-visual, in non-synesthetic individuals. Although these results seem convincing, they can’t be completely conclusive because there is no way to tell the extent to which the patients experienced these synesthesia-like moments as well as difficulty in controlling for a placebo effect, as the participants may have already expected to have these experiences when administered the drugs. 

What would this have been like with synesthesia?

Recent research on psychoactive compounds has found that they may have further implications beyond recreational synesthetic experiences. A 2015 study looked at the effect of psilocybin to reduce suicidal thoughts and attempts (Hendricks et al., 2015). This was done by comparing four separate groups of individuals who had responded to the National Survey on Drug Use and Health. These individuals were grouped based on their lifetime use of psychedelic drugs. In their lifetimes, they had either used psilocybin only, psilocybin & other psychedelics, non-psilocybin psychedelics only, or no psychedelics. They were then asked if they had experienced psychological distress in the past month, or suicidal thoughts or attempts in the past year. The most notable finding from this study was that the psilocybin only group had experienced any of these three outcomes significantly less than the no-psychedelics group (Hendricks et al., 2015). These findings begin to suggest that psilocybin may have therapeutic potential. However, this study does have it’s downfalls as all the participants were drug users, whether or not they used psychedelics. Thus, psychedelic users need to be compared to non-drug users to provide more conclusive results. 

These two studies show that while psychedelics could provide synesthetic experiences, we could possibly even see them used to treat mental health in the future, too. One thing is for sure, though: synesthesia was not necessary to fully experience Paris and our various excursions. Whether we were chaotically experiencing visual and auditory stimuli while navigating the crowded streets, or calmly taking in gustatory and olfactory stimuli in Arles, we consistently combined different sensations to create memorable experiences over the course of the program. 

Sources:

David Luke and Devin Terhune (2013) The induction of synesthesia with chemical agents: a systematic review. Front Psychol. 4: 753

Hartman A. M., Hollister L. E. (1963) Effect of mescaline, lysergic acid diethylamide and psilocybin on color perception. Psychopharmacologia 4: 441–451

Jeremy Daniel and Margaret Haberman (2017) Clinical potential of psilocybin as a treatment for mental health conditions. Ment Health Clin. 7(1): 24-28

Marcus R. Watson, Kathleen A. Akins, Chris Spiker, Lyle Crawford and James T. Enns (2014) Synesthesia and Learning: a critical review and novel theory. Front. Hum. Neurosci. 8: 98

Peter S Hendricks, Matthew W Johnson, and Roland R Griffiths (2015) Psilocybin, psychological distress, and suicidality. J Psychopharmacol. 9: 1041-1043

Images: 

Garden pics taken by Harry

World Cup game pic taken by Anika

Synesthesia art: https://www.sciencefriday.com/segments/the-color-of-music/

 

Get Spotify ASAP

Music has been especially on my mind this past week. Last Friday I had the chance to explore Paris on the day of the Fête de la Musique, a day where people from all cultures and backgrounds sing whatever their heart desires, in different corners of the streets all around Paris. Easily one of the highlights of my time in Paris.

A man singing his heart out on the day of the Fête de la Musique

This area near the Seine was packed with people on the day of the Fête de la Musique

As I was reflecting on how music is part of my daily life, I realized that I have spent a whole lot of time listening to music while studying. In Paris, the days I find a seat on the jam-packed metros, I usually find myself thinking about fairly random things. But since on Thursdays we have quizzes, I refrain from day dreaming and try to review the quiz material while listening to music, while also trying to keep an eye on my bag, and while making sure I don’t miss my stop. Multi-tasking at its best (or worst some could argue) … I started wondering about the possible positive or negative impacts of listening to music, on the brain, more specifically in terms of the impact on learning and cognitive ability.

To investigate this, it is necessary to first gain a general understanding of the important research that is showing mixed results for the effects of background music. The “Mozart effect” has been a topic of great debate. It has been shown that those who listened to the Mozart sonata before performing better on tasks evaluating spatial abilities as compared to the control group that hadn’t listened to any music (Rauscher et al.,1993). What was interesting was that the authors claimed that even though in their experiment they had exposed the participants to the music before the task, music should have the same positive effect while learning too (Lehman and Seufert, 2017).

However, other researchers pushed back on these claims and expanded on the previously done research. The arousal-mood hypothesis suggests that it is not listening to the background music that directly impacts spatial and cognitive abilities (Husain et al., 2002). Instead, it is the impact that background music has on arousal and mood, which may affect learning. Essentially, listening to something pleasant may have a positive impact on cognitive performance and learning (Husain et al., 2002).

Contrarily, Rey (2012) makes the argument that background music could actually negatively impact learning. This was definitely not good news for me… When I started thinking about my own experience, I realized that listening to music while studying does make the process of studying slower, but I have been continuing to do it because the music keeps me entertained while studying! Interestingly, since it can be an additional burden on memory, “distracting” background music has been called a “seductive detail” (Rey 2012). Background music can distract from the main academic task and therefore can negatively impact learning outcomes (Jäncke and Sandmann, 2010; Hallam et al., 2002).

As you can tell, the research on background music has mixed results. Even though there are studies suggesting that listening to music during a learning task may be detrimental to learning, there has been an increasing amount of research on the ways in which listening to music in general, not necessarily during a task, can actually lessen the severity of cognitive aging. But in what way exactly does music impact the brain? One study suggested that music can improve memory performance in older individuals, by decreasing their prefrontal cortex activity (Murray and Ranganath, 2007).  Firstly, what is the general role of the prefrontal cortex and how exactly can its activity be measured? The prefrontal cortex plays an important role in decision making, including more complex decisions. The dorsolateral prefrontal cortex (DLPFC), which is the part of the brain that the researchers focus on in this study, is engaged during cognitive tasks that require processing structure and relationships between items (Murray and Ranganath, 2007).

The authors measured the activity of the DLPFC using a functional near-infrared spectroscopy (fNIRS) system. fNIRS is a non-invasive way to measure brain activity during cognitive tasks (Ferreri et al., 2014). The study by Ferreri et al., (2014) collected fNIRS data, measuring DLPFC activity, from 16 older individuals (around 65 years old) while they were presented with words, with or without a musical background. The adults were better able to remember and describe contextual details when words were presented with music (Ferreri et al., 2014).

The interesting part is that the results from the Ferreri et al., (2014) study were in conflict with previous research that suggests that the DLPFC’s activity usually increases when more structured items are presented (Bor et al., 2003). One of the proposed explanations is that when the DLPFC is deactivated, other brain regions may be activated. The authors suggest that the brain regions that may be activated are the regions of the brain that are implicated in reward (ventral tegmental area and nucleus accumbens), pleasure and memory encoding (Ferreri et al., 2014). This makes complete sense if you think about it in terms of your personal experience: music most definitely evokes emotion. So, the authors propose that deactivation of the DLPFC is accompanied by activation of these pleasure and reward areas that also play a role in memory encoding, resulting in improved learning and memory performance (Ferreri et al., 2014).

“Pleasure/Reward Pathway”: Depicting the prefrontal cortex, nucleus accumbens and ventral-tegmental area

Access to music is inexpensive and widely accessible, making it a great tool for clinical intervention. There is evidence suggesting that music therapy may be useful in slowing cognitive decline in individuals with Alzheimer’s disease and dementia (Fang et al., 2017). There was even a study that showed that music can actually be used to stimulate recollection of personal memories in individuals with Alzheimer’s disease (Chevreau et al., 2017)!

So, as you can hopefully tell, intriguing work is being done on the neurological impacts of listening to music but also the potential ways in which music can actually be used as part of clinical treatment or as a therapeutic tool. So now maybe investing in that Spotify subscription is not a bad idea…

References
Bor D., Duncan J., Wiseman R. J., Owen A. M. (2003). Encoding strategies dissociate prefrontal activity from working memory demand. Neuron 37, 361–36710.1016/S0896 6273(02)01171-6

Chevreau, Priscilia & Nizard, Ingrid & Allain, Philippe. (2017). Retrieval of memories with the help of music in Alzheimer’s disease. Geriatrie et Psychologie Neuropsychiatrie du Vieillissement. 15. 309-318. 10.1684/pnv.2017.0689.

Fang, R., Ye, S., Huangfu, J., & Calimag, D. P. (2017). Music therapy is a potential intervention for cognition of Alzheimer’s Disease: a mini-review. Translational neurodegeneration, 6,2. doi:10.1186/s40035-017-0073-9

Ferreri, L., Bigand, E., Perrey, S., Muthalib, M., Bard, P., & Bugaiska, A. (2014). Less Effort,Better Results: How Does Music Act on Prefrontal Cortex in Older Adults during Verbal Encoding? An fNIRS Study. Frontiers in human neuroscience, 8, 301.doi:10.3389/fnhum.2014.00301

Hallam S, Price J, Katsarou G. (2002). The effects of background music on primary school pupils’ task performance. Educ Stud. 28:111–122. doi: 10.1080/03055690220124551.

Husain G., Thompson W. F., Schellenberg E. G. (2002). Effects of musical tempo and mode on arousal, mood and spatial abilities. Music Percept. 20 151–171. 10.1525/mp.2002.20.2.151

Jäncke, L., & Sandmann, P. (2010). Music listening while you learn: no influence of background music on verbal learning. Behavioral and brain functions : BBF, 6, 3. doi:10.1186/1744-9081-6-3

Murray L. J., Ranganath C. (2007). The dorsolateral prefrontal cortex contributes to successful relational memory encoding. J. Neurosci. 27, 5515–552210.1523/JNEUROSCI.0406 07.2007

Rauscher F. H., Shaw G. L., Ky K. N. (1993). Music and spatial task performance. Nature 365611. 10.1038/365611a0

Pleasure Pathway Image. Retrieved from https://learn.pharmacy.unc.edu/substance/node/6

All other images taken by me

There is Peace in Harmony

Maybe you can’t stop listening to the pop-harmonies of Taylor Swift or perhaps you find yourself enjoying the elusive “up-and-coming” SoundCloud rappers. Regardless, even with these dissimilarities, we can all agree on the fact that some chords sound ‘good’ and others notes brawl when they’re played at the same time outlining the idea of consonance versus dissonance.

Figure 1. (A) represents a consonant interval while (B) represents one of dissonance. Solid lines indicate the frequency components of the root note; dotted lines represent the frequency components of the interval note.

Music is a universal human phenomenon. An understanding of the underlying auditory processing concerned with listening to music may unravel which musical parameters are innate in our biology. Behavioral studies have shown that listeners prefer consonant intervals and assign them a higher status in hierarchical rankings (Plomp and Levelt, 1965). It is this hierarchical organization of pitch that contributes to the sense of a musical key and pitch structure in Western music (Rameau, 1722).

In any case, the question remains: why is it that we prefer consonance over dissonance? Bones et al. (2014) hypothesized that the perception of consonance can be accounted for by the neural representation of harmonicity (the closeness of fit of two notes). To test their hypothesis, participants were presented with dyads (two-note chords) made up of a lower note (the ‘root’) and a higher note (the ‘interval’) and asked to rate them on their pleasantness or unpleasantness.

To test the effects of interactions within the cochlea, researchers also measured the electrophysiological frequency following response (FFR). FFRs are neural signals generated in the brain when people hear sounds as measured by frequency components. FFRs were recorded in two scenarios: when each dyad was presented to both ears (diotic) or one note assigned to each ear (dichotic). To measure the strength of the representation of harmonicity, a neural consonance index (NCI) was calculated giving a quantitative look into how consonant a dyad is
perceived.

Figure 2. Schematic of dichotic vs. diotic listening tasks.

The results of this study establish that average dyad pleasantness ratings are consistent with prior studies in that consonant dyads were more pleasant over dissonant dyads (Bidelman and Krishnan, 2009; McDermott et al., 2010). Consonance preference for differing intervals was found to have a close correspondence to the neural representation of harmonicity as reflected in the FFR. Additionally, when the dyads were presented to both ears, the perception of consonance was higher than when the two notes were presented to separate ears. The FFR showed a stronger representation of harmonicity in the diotic scenario and interactions between the harmonics of the two notes on the basilar membrane of the cochlea resulted in further frequency components being present in the FFR. Therefore, a diotic scenario enhances the consonance of a sound. Overall, the research suggests that a preference for consonance depends both in part by the neural representation of harmonics as well as their cochlear interactions.

One weakness of this study is its specificity to Western music. In a study of Tsimane’s – a native Amazonian society – in comparison to Western culture found that cultures sufficiently isolated from Western music are devoid of consonance preference (McDermott, 2016). Thus, it is unlikely that there is an innate bias toward harmonic sounds (McDermott, 2016). However, there are conflicting studies regarding infants’ ability to show preference for consonant sounds (Trainor, 2002) that suggest that it is indeed innate. There is no conclusion in Bones et al. (2014) regarding the innateness of consonance preference. The confliction of these studies leads to confusion in their conclusions.

In general, this study provided great insight into the neural components of what makes consonance sound so right. Though we may not be able to figure out if this is innate or learned, it can at least be agreed upon that Westerns find more peace in harmony.

 

References 

Bidelman GM, Krishnan A (2009) Neural correlates of consonance, dissonance, and the hierarchy of musical pitch in the human brainstem. Journal of Neuroscience 29(42):13165-13171. doi: 10.1523/JNEUROSCI.3900-09.2009 

Bones O, Hopkins K, Krishnan A, Plack CJ (2014) Phase locked neural activity in the human brainstem predicts preference for musical consonance. Neuropsychologia 59:23-32. doi: 10.1016/j.neuropsychologia.2014.03.011

McDermott JH, Hauser MD (3005) The origins of music: Innateness, uniqueness, and evolution. Music Perception 23(1):29-59. doi: 10.1525/mp.2005.23.1.29

McDermott JH, Schultz AF, Undurraga EA, Godoy RA (2016) Indifference to dissonance in native Amazonians reveals cultural variation in music perception. Nature 535:547-550. doi: 10.1038/nature18635

Rameau JP (1722) Treatise on harmony. Reprint. New York: Dover, 1971

Plomp R, Levelt WJM (1965) Tonal consonance and critical bandwidth. Journal of the Acoustical Society of America 38:548-560. doi: 10.1121/1.1909741

Trainor LJ, Tsang CD, Cheung VHW (2002) Preference for Sensory Consonance in 2- and 4-Month-Old Infants. Music Perception 20(2):187-194. doi: 10.1525/mp.2002.20.2.187

Pictures

Figure 1: Bones O, Hopkins K, Krishnan A, Plack CJ (2014) Phase locked neural activity in the human brainstem predicts preference for musical consonance. Neuropsychologia 59:23-32. doi: 10.1016/j.neuropsychologia.2014.03.011

Figure 2 Girl: (https://www.vectorstock.com/royalty-free-vector/person-with-headphones-icon-image-vector-14803217)

Figure 2 Music notes: (https://en.wikipedia.org/wiki/Musical_note)

Views (not from the 6)

Throughout our time in Paris, we have seen beautiful artwork in the form of paintings, music, sculpture, dance, and much more. Art is all about perception and I have been so grateful to be able to see and experience Monet’s use of color or Van Gogh’s use of texture. I have had the opportunity to be moved by their brush strokes and see the way they can turn an ordinary scene into a masterpiece. As I walked through the Musée d’Orsay and Musée Rodin, I was in awe of what I was seeing. I could see the level of detail and the individual brush strokes that were so meticulously planned. I had a completely different understanding of how they viewed the world because of their artwork. Looking at Monet’s series of the water lilies, I could tell how light affected his work. Seeing Rodin’s Thinker in real life showed me how much he focused on the hands and facial expressions. Just by seeing the artwork, there was so much I could discern about the artist and time.

Van Gogh’s Wheat Fields

Rodin’s Thinker

 

 

 

 

 

 

 

However, not everyone has the same privilege as I do. People suffering from visual impairments, specifically cortical blindness, do not have the same opportunities as I do to experience and appreciate the visual arts. The way they can perceive art is significantly different because they can’t see the details like we can. This, however, doesn’t mean they can’t be a part of the visual art world! There are a lot more ways to engage visually impaired patients and bring their perspectives of the world to the forefront.

A study done in Poland has suggested that even those with visual impairments can create artwork that is recognizable by individuals without impairments (Szubielska, 2018). In this study, the author asked patients with cortical blindness and others less severe forms of visual impairment to come explore the arts in Poland through guided tours. The author wanted to allow the patients to feel more comfortable with visual art before asking them to attempt to make their own. These visually impaired individuals were given the opportunity to go through art workshops and at the end, their work was displayed to the public for exhibition (Szubielska, 2018). The artwork was shown in very dim lighting or

Sculpture made by visually impaired artist

viewers were given blindfolds to recreate how a lot the visually impaired artists perceived the world. The author found that sculptures made were easier to make out because of their three-dimensional characteristics (Szubielska, 2018).  Even though there was no analysis or calculation of significance, this study shed light on the effects of visual impairments on creativity and helped the general public understand that art can be created without sight (Szubielska, 2018).

 

Through this new platform, people walked through the exhibit and got to experience art through a unique perspective and comprehend the struggles visually impaired people face every day. For example, one visually impaired artist drew a stairwell as a way of expressing his voice that stairs are difficult to maneuver for visually impaired people (Szubielska, 2018). Exposure to this typeof art help shape perspective because recurring experiences help shape the way we perceive the world (Snyder et al, 2015). By displaying the artwork and allowing visually impaired individuals to express themselves creatively, the increase in attractiveness of their work increases because repeated perception of the same stimulus makes them more attractive (Snyder et al, 2015). Overall, even though this exhibition in Poland was very subjective, it was a great start to demonstrating differences in perception and how these experiences can help us gain a broader perspective. Hopefully it can lead to exhibitions by visually impaired artists in Paris and work by Van Gogh and Rodin displayed for visually impaired people to enjoy and appreciate as well!

 

References

Snyder JS, Schwiedrzik CM, Vitela AD, Melloni L (2015) How previous experience shapes perception in different sensory modalities. Frontiers in Human Neuroscience9.

Szubielska M (2018) People with sight impairment in the world of visual arts: does it make any sense? Disability & Society33:1533–1538.

 

Imagaes

Photo 1 and 2 were taken by me

Photo 3: Szubielska M (2018) People with sight impairment in the world of visual arts: does it make any sense? Disability & Society33:1533–1538.

Electric Feel

A section of the museum! Daft Punk, an electric music duo, is French.

While travelling in Paris, I’ve passed quite a few musicians performing on the streets, whether they are singing, playing an instrument, or both. As someone who listens to music almost nonstop, I always find myself feeling a little brighter after I pass by these performers during my daily outings. What can I say? Music makes me happy, and good music happier. It’s not often that one finds time and space just for listening to music, but the “Electro: From Kraftwerk to Daft Punk” exhibit at the Philharmonie de Paris offered me this very opportunity, revisualizing the sonic experience of electronic dance music (EDM) into an immersive physical space. Tracing the origins of EDM to the present and featuring the works by renowned duo Daft Punk, “Electro” left me thinking about EDM for quite some time after I’d left. How do our brains process and respond to music, and how might the case be different for EDM?

I went to Shaky Beats music festival a year ago. The festival had several EDM artists playing.

Research suggests that listening to music is more complex than we might think, as it activates an entire network of cortical and subcortical areas (Zatorre and Krumhansl, 2002). Even the perception of rhythm involves multiple brain regions (Zatorre et al., 2007). When we hear music we like, our reward systems may activate, and when we tap our feet or bob our heads, we do so almost unbeknownst ourselves through activation of the basal ganglia (Trost et al., 2014; Zatorre et al., 2007).

A recent functional magnetic resonance imaging (fMRI) study by Brodal and colleagues examined the relationship between rhythmic music and basal ganglia, an area of the brain typically associated with fine motor skills (Hikosaka et al., 2002; Brodal et al., 2017). To test participants, researchers created a continuous-stimulation design (10.16 minutes long, 120 beats per minute) using an EDM-style composition. Ambient noise generated by the MR scanner was synchronized with the music to mimic an accompanying instrument and to prevent disturbance of participants’ listening experiences. The continuous-stimulation design was a departure from previous studies’ use of short chunks of music, which Brodal and colleagues believed may have caused limitations (Brodal et al., 2017).

Regions researchers observed. (Brodal et al., 2017)

Researchers used stochastic dynamic causal modeling (sDCM), a technology used to examine interactions between auditory perception, rhythm processing, and reward processing, to observe connectivity in the auditory cortex, putamen/pallidum (PP), and ventral striatum/nucleus accumbens (VSNAc) of both hemispheres. The latter two grouped terms were chosen for this study because the low resolution of raw fMRI data prevented distinction between grouped locations.

The sDCM revealed significant connections between all three areas in both hemispheres, as well as reduced functional connectivity in the reward system. Results supported the hypothesis that stimulation from rhythmic EDM-like music decreases connectivity in the right VSNAc from and to the basal ganglia and auditory network. Stimulation also resulted in decreased self-inhibition via the VSNAc, as well as changed hemodynamic parameter of the VSNAc, suggesting an increased level of activation. Furthermore, reduced connectivity was observed in basal ganglia, reward system, basal ganglia and auditory network. Ultimately, results demonstrated reduced reward system connectivity in participants listening to rhythmic music, thus supporting the hypothesis that the ventral striatum/nucleus accumbens region plays a significant role in processing the emotions associated with listening to music (Koelsch, 2014).

As Brodal and colleagues note themselves, one weakness of the study is its methodological constraints. Though evidence already exists on rhythm and the observed effects, researchers’ use of only one music piece prevents confident establishment of a connection, at least in relation to the present study (Brodal et al., 2017). Furthermore, participants’ states while listening to the given music is only compared to one other state, the resting state. Brodal and colleagues note that it is thus impossible to definitively determine whether the observed effects emerged during the resting state (Brodal et al., 2017). Lastly, though not a weakness, laboratory conditions in the Brodal team’s study are far different from normal conditions in which one might listen to music. EDM in particular is often celebrated at large outdoor festivals, and it would be interesting to understand how music interacts with festival environments and other relevant factors to affect our emotions, reward circuits, and capacity for inhibition.

Or who knows? Maybe I’ll see for myself at my next EDM festival. In an era of increasing technologization, electronic music represents not only technology, but also the capability of technology to bring humans together. And it’s comforting knowing that something so powerful can serve us by bringing us joy.

 

References

Brodal HP, Osnes B, Specht K (2017) Listening to rhythmic music reduces connectivity within the basal ganglia and the reward system. Frontiers in Neuroscience. 11:153. https://doi.org/10.3389/fnins.2017.00153.

Hikosaka O, Nakamura K, Sakai K, Nakahara H (2002) Central mechanisms of motor skill learning. Current Opinion in Neurobiology 12(2):217-222. https://doi.org/10.1016/S0959-4388(02)00307-0.

Koelsch S (2014) Brain correlates of music-evoked emotions. Nature Reviews: Neuroscience. 15:170-180. https://doi.org/10.1016/j.plrev.2015.03.001.

Cité de la Musique: Philharmonie de Paris (n.d.) The Electro exhibition.

Trost W, Frühholz S, Schӧn D, Labbé C, Pichon S, Grandjean D, Vuilleumier P (2014) Getting the beat: Entrainment of brain activity by musical rhythm and pleasantness. NeuroImage 103:55-64. https://doi.org/10.1016/j.neuroimage.2014.09.009.

Zatorre RJ, Chen JL, Penhune VB (2007) When the brain plays music: Auditory-motor interactions in music perception and production. Nature Reviews: Neuroscience 8:547-558. https://doi.org/10.1038/nrn2152.

Zatorre RJ, Krumhansl CL (2002) Mental models and musical minds. Science 298:2138-2139. https://doi.org/10.1126/science.1080006.

Image 1-2 taken by myself

Image 3 taken from (Brodal et al., 2017).

Image

Coffee: For Optimal Results Find Your Caffeinated Balance

I love my coffee black. No sugar, no cream, just the rich, complex flavor of the world’s most beloved bean. It’s part of my daily ritual, either in the morning or afternoon or on special days both. When the first taste hits, I feel the smooth bitter taste swirl in my mouth, the notes of fruit or chocolate, the acidity, and the warmth blend together, and my mood is elevated. I am more alert, the coffeeshop I am sitting in enters the periphery and the assignment or tasks in front of me take precedent. After coffee, I feel more in control of my day, more optimistic, and generally happier and bubblier.

Coffee also opens the door to a unique world that transcends language. Every city, including Paris, has their own haven of coffeeshops, equipped with a variety of beans and a melancholy playlist perfect for work. Given its wide appeal, it unsurprising to discover that researchers are curious about its effects. Recently, Haskell- Ramsay et al, 2018 studied the acute effects of black coffee on cognition and mood amongst young people (20-34 years old) and older adults (61-80 years). Mainly Haskell-Ramsey et al, 2018 wanted to know whether it was the caffeine in the coffee that was causing these increased mood benefits or the behavioral components of drinking coffee. In order to test this, a randomized, placebo-controlled, double-blind, counterbalanced-crossover study was used on 72 participants under three conditions: intaking 220 mL water mixed with 2.5 g coffee flavouring (placebo),220 mL regular coffee (without milk and sugar) containing 100 mg caffeine, and 220 mL decaffeinated coffee (without milk and sugar) containing ~5 mg caffeine.

Participants took cognitive assessment tests and mood measurement tests via the Computerized Mental Performance Assessment System (COMPASS) before drink intake and 30 minutes after. This metric is common in caffeine research and includes learning object locations and driving in PC simulations (Stalmach et al, 2014). Additionally, a saliva swab was taken and a caffeine research visual analogue scale was used to identify participant’s emotional and energy state prior to coffee intake. The researchers took rigorous measures in ensuring the participants were in proper testing conditions prior to intake. No coffee was consumed 24hours before the experiment, a proper breakfast was eaten at least one hour before the participants came to the lab, and a food diary were maintained (Ramsey et al, 2018). Further screening occurred the day of the study to make certain everyone was eligible.

The results were fascinating. For rapid visual information processing, object location learning, and alertness, caffeinated coffee showed statically significant difference than decaffeinated drinks. Consumption of caffeinated coffee also resulted in mood elevation and other cognitive tasks, and these benefits were seen across age groups. In the conclusion, the authors discuss that the benefits of coffee last between 4-6 hours (Stalmache). However, testing of mood and cognitive behavior were measured between 30 minutes to 120 minutes. I would be curious in future studies to see if these benefits declined, specifically if caffeine crashes led to the opposite of the positive effects of this study. Additionally, I would be interested to compare drinks with the same caffeine content to coffee and see if the mood and cognitive metrics changed. Coffee contains many chemical compounds that could be attributing to these positive effects compared to an energy drink, tea, or caffeine pill (Carrillo et al, 2000). Lastly, this study limited caffeine intake to 100mg. Does taking more than 100mg contribute to these heightened emotional and cognitive states or could it have a backfiring affect?

To better understand the beneficial parameters of caffeine and its effect on the body, Santos et al, 2016 studied the behavioral response when zebra fish were given different caffeine dosages. 144 adult zebrafish of both sexes were given one of 12 caffeine dosages: the lowest being 0.5 and the highest being 150.0mg. Caffeine was added directly to a tank containing twelve zebra fish and then observed for 60 minutes (Santos et al, 2016). For total distance traveled and freezing behavior, both were enhanced with caffeine exposure of 10 and 25mg/L, but decreased when fish were in water containing 50mg/L. Caffeine’s role in the nervous system, specifically alerting the body and enhancing performance, mainly occurs at an intermediate dose- too little no enhancement, too much a backfiring. This study is limited in its scope, however, because the zebrafish likely have never been exposed to caffeine before. However, human can be regular coffee drinkers. These studies did not account for the behavioral and mood differences found in those who regularly consume coffee as opposed to occasionally or never. The different dosages and level of dependency after years of drinking can affect the benefits of caffeine (Meredith et al, 2013).

Furthermore, these two studies focused on direct consumption of caffeine either in black coffee or directly placed in the tank, but would cream and sugar affect the effectiveness of caffeine? At home, I was a fiend for black coffee, hot or iced, but in Paris, I have become a latte gal, even indulging in the occasional espresso or flat white. Espresso based drinks such as a latte or flat white feel like a spurt of energy hitting me all at once. While coffee tends to be a slower burn, a slightly elevated state steady throughout the day. Regardless of form, coffee makes everything undeniably better, and in the right quantity can improve function. The Parisians may love wine, but I would take a latte over a bottle any day of the week.

 

Carrillo, J.A.; Benitez, J. Clinically significant pharmacokinetic interactions between dietary caffeine and medications. Clin. Pharmacokinet. 2000, 39, 127–153.

 

Haskell-Ramsay, C., Jackson, P., Forster, J., Dodd, F., Bowerbank, S., & Kennedy, D. (2018). The Acute Effects of Caffeinated Black Coffee on Cognition and Mood in Healthy Young and Older Adults. Nutrients, 10(10), 1386.

 

Meredith SE, Juliano LM, Hughes JR, Griffiths RR. Caffeine Use Disorder: A Comprehensive Review and Research Agenda. J Caffeine Res. 2013;3(3):114–130.

 

Santos, L. C., Ruiz-Oliveira, J., Silva, P. F., & Luchiari, A. C. (2017). Caffeine Dose-Response Relationship and Behavioral Screening in Zebrafish. The Question of Caffeine.

 

Stalmach, A.; Williamson, G.; Crozier, A. Impact of dose on the bioavailability of coffee chlorogenic acids in humans. Food Funct. 2014, 5, 1727–1737.

 

Oat Milk Latte

Almond Milk Latte

From EDM to Country Music

This week our class took a trip to the Philharmonie de Paris where we explored the Electro Exhibition titled Kraftwerk to Daft Punk. I was especially excited to see this exhibit because I love electronically produced music and it is prevalent in most of my daily activities. Personally, I like listening to more chill, “low-fi hip hop beats” type of music when I’m studying (ODESZA is my go to, see playlist clouds), and more upbeat and rave-like music while I run (Illenium is a personal favorite, see playlist run). Learning about the history and origins of electro to techno music and the cultural significance from clubs to raves increased my appreciation for the music I listen to daily.

Album cover for A Moment Apart by ODESZA, 10/10 would recommend for study music

While I also like other types of music for other occasions, one music genre I will not listen to is country (except maybe Old Town Road). To me, country music just isn’t enjoyable and being in the south at Emory for the past 3 years hasn’t changed my opinion. However, my music taste had me thinking, what’s the neuroscience behind music preference? Is there a difference in my brain when I listen to songs I like and dislike compared to someone who loves country music but hates electronic music? A study conducted by Wilkins et al. uses network science on the brain to see the connectivity between brain regions when we listen to our favorite song, songs that we like, and songs that we dislike (Wilkins et al., 2014). Network science in neuroscience is an emerging field that studies the brain as a complex network by mapping, recording, and analyzing the interactions between different brain regions (Bassett and Sporns, 2017). In this study, 21 young adults with different music genre preferences and different music backgrounds were asked to listen to five iconic songs categorized in the genres classical, country, rap/hip hop, rock, an unfamiliar genre such as Chinese opera, and their personally selected favorite song. While the subjects listened to the full song, functional magnetic resonance imaging (fMRI) data was collected. fMRI is a technique that measures brain activity by detecting changes in blood flow.

During the fMRI scan, subjects were also asked to rate whether they liked or disliked the song being played on a scale. Four network science statistics, degree, global efficiency, local efficiency and community structure, were used to quantify the data. Degree distribution is a measure of how many other nodes a specific node is connected to, thus the greater the degree distribution, the more connections there are from a specific area. Global efficiency (Eglob) is a measure of distance between one node and another, thus a greater Eglob indicates shorter distance from one node to the rest of the network (Bassett and Sporns, 2017). Local efficiency (Eloc) is like global efficiency but on a smaller scale that measures local connectivity (Bassett and Sporns, 2017). Lastly, community structure identifies the nodes that are more connected to each other rather than to other parts of the brain.

Results showed that in all participants, the default mode network (DMN) and the precuneus in particular have the highest degree nodes in the brain when listening to the songs, regardless of genre preference. The DMN is a network of brain regions including the precuneus that is involved in introspection and reprocessing of memories (Greicis et al., 2003).

fMRI of brain regions in the DMN

There is also significantly higher global efficiency in the precuneus when subjects listened to songs they liked compared to songs they disliked, meaning there were closer connections within the precuneus when subjects listened to songs they liked. There is no significant difference in local efficiency between liked, disliked, and favorite song condition. Additionally, there was a greater dissociation/fewer connections between the precuneus and another brain region in the DMN in the dislike condition compared to the like condition. The authors did not state whether this difference in community structure was significant or not, but this information could have strengthened the authors’ hypothesis that there are differences in neural activity when we listen to music we like and music we don’t like.

Differences in community structure between Like and Dislike conditions. In the Like condition there is more connectivity between the precuneus and other parts of the brain compared to the Dislike condition.

Overall, there is a difference in brain connectivity when I listen to electronic music compared to when I listen to country music and this same activity is present in someone else who likes listening to country music but not electronic music. The exact reason for this connectivity difference is not yet known but the fact that we now know that there is an association between brain connectivity patterns and music preference brings us closer to understanding the neuroscience of music preference. So I guess one thing I can say I have in common with those who like country music is that we have similar neural connectivity when we listen to the music we like.

References

Bassett, D. S., & Sporns, O. (2017). Network neuroscience. Nature Neuroscience, 20, 353-364.

Greicius, M. D., Krasnow, B., Reiss, A. L., & Menon, V. (2003). Functional connectivity in the resting brain: A network analysis of the default mode hypothesis. PNAS, 100(1), 253-258.

Wilkins, R. W., Hodges, D. A., Laurienti, P. J., Steen, M., & Burdette, J. H. (2014). Network science and the effects of music preference on functional brain connectivity: From Beethoven to Eminem. Scientific Reports, 4.

https://en.wikipedia.org/wiki/Default_mode_network#/media/File:Default_mode_network-WRNMMC.jpg

 

 

Nighttime in the City of Lights

During the day, Paris is a bustling metropolitan city, housing thousands of people as they take to the streets on their way to work. Once the sun sets, however, I begin to understand why this is the City of Lights. The Eiffel Tower lights up much of the night sky, twinkling at the onset of each new hour. While daytime bakeries close, late-night restaurants and cafes open their doors to the evening-inclined general public. On late night walks back to my apartment, I never fail to notice Parisian couples lounging at an outdoor café, enjoying the nighttime air with a drink and a pastry. Here, it seems to be a widely recognized and embraced concept that Parisians are night-folk.

Long after the sun sets, the lights of Paris are still up and brighter than ever. View from a street corner blocks from the Eiffel Tower.

This is a far cry from the nighttime environment in my hometown, a city on the outskirts of the Metro Atlanta area. I was always used to complete darkness at night, with no late-night city life to brighten the night sky. Even in Atlanta lights don’t shine quite as brightly. While I think the Parisian street scene is charming and I absolutely adore its thriving nightlife, it has left me struggling to get to sleep in the city where the lights never fade.  I’ve only been here a month, but I wonder how all of this consistent light affects the sleeping patterns of the average Parisian relative to the people living in smaller, less heavily lit areas. Does the constant exposure to bright city lights at night-time in cities like Paris result in later sleep cycles that significantly differ from populations living in areas with less nighttime light pollution?

To answer this question, it is important to understand how variation in sleep cycles is defined. People can be sorted into two groups based on their times of wakefulness and alertness – “morning” or “evening” type people. These distinctions refer to a person’s chronotype, which measures individual differences in lifestyle and alertness in the morning versus the evening (Sun 2019). Morning-type people are more likely to get up earlier and exercise more, while evening-types typically go to sleep later, eat later, and wake up later. Based on the social environment alone, Paris seems to encourage more evening-oriented people.

Image result for morning vs evening type chronotypes

Both chronotypes depends on chemical signaling in the brain to fall asleep at their respective times. Sleep relies on a neurotransmitter known as melatonin, a hormone operating in synchronicity with the onset of nighttime darkness. Melatonin is important for regular and consistent sleep, and delays in its release are expected to play a role in sleep disorders such as insomnia (Shechter 2018). This means that any factor that influences the release of melatonin prolongs wakefulness at night and causes difficulties in getting to sleep. One factor that has continuously shown associations with these delays is presence of light during and leading up to sleep (Shechter 2018). If light is present on a consistent basis, the regular delay of melatonin can cause an adjustment in chronotype towards being more evening inclined. In addition to delaying melatonin production, light alerts parts of the brain that control initiation and maintenance of sleep. (Sun 2019).

As shown above, melatonin is active in the dark. Presence of light inhibits the melatonin pathway and delays sleep.

A study compared circadian patterns between residents of a rural town and members of a small urban area (Carvalho 2013). They had a similar question, and collection of data involved comparison of light exposure and sleep patterns, as well as a structured chronotype questionnaire. The results they obtained show a significant difference between rural and urban populations in spread of chronotypes: the rural subjects showed a predominantly morning chronotype while the urban subjects were predominantly evening-oriented.

As shown above, there is a significantly difference between rural and urban subjects with regards to chronotype.

Their reasoning was that rural workers are exposed to sunlight during the day while they work, which reinforces the need to sleep when the sun goes down. Since urban citizens typically do not work outside, in-the-sun jobs, they are not exposed to as much natural sunlight and do not have their sleep cycles naturally reinforced. Instead, they tend to work technology-based jobs where they are at a computer screen (Carvalho 2014). This results in increased intake of bright and unnatural light, which is independent of the actual daylight (as one can use a computer at night). This would align with the Parisian lifestyle of bright light that is inconsistent with the light of the sun, which tampers with the natural sleep cycle. This reasoning was a strength of the study and proved their conclusion with valid evidence.

A weakness of this study was that it failed to address the possibility of other factors that may have influenced their data. The results they received were very strong, but the influence of light could have been a correlation instead of a causation. They made no effort to test for other variables that may have impacted results, such as timing of social events, parents with young children who require continuous attention, and other non-light related factors.

Based on these results, it looks like the late-night hustle and bustle does have a neurological effect on sleeping patterns. While it doesn’t hurt to be on the computer past sunset, it is clear that continued light during nighttime delays melatonin release on a consistent scale, which can result in the shifting of sleep cycles to an evening chronotype. Turns out there may be some nighttime benefits to living in small towns after all!

References:

Carvalho, F. G., Hidalgo, M. P., & Levandovski, R. (2014). Differences in circadian patterns between rural and urban populations: An epidemiological study in countryside. Chronobiology International, 31(3), 442-449.

Shechter, A., Kim, E. W., St-Onge, M., & Westwood, A. J. (2018). Blocking nocturnal blue light for insomnia: A randomized controlled trial. Journal of Psychiatric Research, 96, 196-202.

Sun, J., Chen, M., Cai, W., Wang, Z., Wu, S., Sun, X., & Liu, H. (2019). Chronotype: Implications for sleep quality in medical students. Chronobiology International, 1-9.

 

Wait for It

As an avid concert-goer, I am no stranger to long lines and long wait times. Now that I am a tourist, I have become even more familiar with the unavoidable exasperation of hanging out with dozens of other tourists as we wait for the airplane, on the escalators, in the metro, or at the tourist attraction.

Lines at Versailles

Lines at Versailles (If you want to see the full video)

However, even though I am familiar with—and expect—the wait, sometimes I look around and wonder what possesses us humans to be willingly (perhaps begrudgingly) shepherded like cattle to arbitrary waiting spaces for what are often ridiculously long periods of time. There have been times that I have waited in line longer than the actual event I went to go experience: for one of the concerts I went to I waited in line from 4PM when the actual event was more around 8-11PM. For me, it was absolutely worth the wait (and the blisters); however, I admit I can see how to an outsider my behavior must seem incredibly irrational. In Europe, the lines have continued to remain an expected aspect in my life; at Versailles, we waited almost two hours to enter the Palace, and according to some people that wait time was not too bad. No one likes waiting—it is a universally hated experience—so what is the social role of waiting? What compels the people who, like me, are willing to wait these absurdly long times?

Wiesel and Freestone (2019) discuss the practicalities of queues and their implications on wider social systems. In their research, they focus specifically on queuing in urban areas, where material resources may be scarce and allocative measures are necessary. Especially in a city like Paris, I have found that I have had to wait in line for the elevator in our building, the cashier at the boulangerie, the turnstiles at the metro—the list goes on and on. Wiesel and Freestone suggest that queues can help build trust in the surrounding strangers and the structural norms of the city; following the “rules” can be seen as an “indicator of integrity” (Giddens 1991), while breaking the rules and “cutting” others can erode social trust and solidarity and increase anxieties about social disorder due to the diversification particularly present in cities like Paris.

Meanwhile, on a neurobiological level, recent research from Miyazaki et al. give evidence for a “model of waiting” that relies on the neurotransmitter serotonin to mediate whether we continue to wait or not based on probability of getting reward and timing of receiving reward. Previously, other researchers have shown that activating more serotonin release in the dorsal raphe nucleus in mice brains will enhance their waiting times for rewards (Fonseca 2015), while lesioning or destroying those neurons will make the mice more impatient (Miyazaki 2012).

Dorsal raphe nucleus

This article builds upon that idea and considers specific parameters when that serotonergic effect is optimized. Using optogenetic stimulation—or using light to activated increased serotonin release in the brain—they found that in order for increased serotonin to increase wait times, the subject must be fairly confident that the reward will happen in the future. In addition, if the reward was very certain to occur, then the effect is more enhanced when the subjects could not predict when the reward would occur.

Their reasoning is that when the timing is more uncertain, it becomes harder to “reject the possibility that the reward may still come” (Miyazaki et al 2018). Though it used to be believed that serotonin works to alter the perception of time, the researchers in this study did not find a consistent pattern of evidence that shows that. Instead, they propose that serotonin may work emotionally to bias us to more positive outcomes and keep us hopeful that the reward will come soon. Specifically, serotonin may help to mediate between the negative experience we have while waiting in the queue and the positive expect beliefs we have about what we are waiting for. While some of their evidence to support their claim could be strengthened—for example, more data to determine how exactly they are determining whether the mice have a “high confidence” in future rewards—their research provides useful insight into the potential role of serotonin in our emotional decision-making.

What does this mean for me while I’m waiting in line? I probably won’t be able to stop being bored, and it’s not like I can stimulate my own neurons to release more serotonin. But between the idea of “building trust” between me and the other Parisians and knowing that there is a neurobiological basis for our willingness to be patient, I know that my wait will be worth it.

 

References:

Fonseca MS, Murakami M, Mainen ZF (2015) Activation of dorsal raphe serotonergic neurons promotes waiting but is not reinforcing. Curr. Biol. 25:306–315.

Giddens A (1991) Modernity and Self-identity. Cambridge. 88.

Miyazaki K, Miyazaki KW, Yamanaka A, Tokuda T, Tanaka KF, Doya K (2018). Reward probability and timing uncertainty alter the effect of dorsal raphe serotonin neurons on patience. Nature Communications.

Miyazaki KW, Miyazaki K, Doya K (2012) Activation of dorsal raphe serotonin neurons is necessary for waiting for delayed rewards. J. Neurosci. 32:10451–10457.

Miyazaki K, Miyazaki KW, Doya K (2011) Activation of dorsal raphe serotonin neurons underlies waiting for delayed rewards. J. Neurosci. 31:469-479.

Ryan G, Hernandez-Maskivker G, Valverde M, Pamies-Pallise M (2018) Challenging conventional wisdom: Positive waiting. Tour. Manag. 64:64–72.

Wiesel I, Freestone R (2019) Queue City: Authority and trust in the waiting line. Geoforum. 100:229-235.

Images 1 taken by me, 2 and video by Alyssa Kim.

Image 3: Valdemiro Carlos Sgarbieri

Image 4: Courtesy of OIST

Just by Looking at It, I Think It’s a Red

Everybody knows that one wine enthusiast that insists you must let the wine ‘breathe’ and exclaims “Ah, we have some truly wide legs on show here! What a treat!”, in response to the swirl of their glass.

Famous for being the city to where Popes fled following the corruption of Rome in the 14th century, Avignon should also be celebrated for its location in the South of France, a region famous for its wine. Though its sanctity should not be understated, its wine must not be either.

Figure 1. Me and two friends at the Carré du Palais wine tasting.

After walking into the refurbished bank vault at the Carré du Palais, the crisp, cool air hit my skin like the droplets of a bright Sauvignon Blanc with notes of Asian pear and celery. As we all took our places, there were 2 clear wine glasses and 1 small black wine glass that, in my blatant naïvety, I thought was for water. After integrating the sommelier for most of the wine tasting’s duration, he informed me that, in fact, the 1 small black wine glass was for white wine. He stated that our perceived taste of the wine can be influenced by the color because, as everyone knows, a deep yellow is probably an aged Riesling and a deep gold is probably a Chardonnay. This is referred to as ‘crossmodal bias’ (Verhagen and Engelen, 2006), a phenomenon in which one sensory modality (vision) can influence another (taste).

Figure 2. The two clear wine glasses and smaller black wine glass that caused confusion.

I thought this was a very fascinating precaution to take. To investigate the relationship between taste and vision, Rolls and Baylis (1994) recorded singular neurons from five macaques. Food related visual stimuli was presented to macaques and directly after, five different taste stimuli were delivered intraorally. It was found that 29.7% of neurons in the primary taste cortex were bimodal; they were found to have visual responses as well as olfactory responses (Rolls and Baylis, 1994). This discovery exhibits the ability of these sensory modalities to ‘communicate’ early on and can help us understand the phenomenon of crossmodal bias.

The sommelier also made a point to smell the wine deeply before taking his first sip. Following in his footsteps, I tried it. Though I didn’t pick up the hints of black current that he was noting, I did get a sense for the taste that was to come. In 1963, Thompson et al. suggested that sensory information entered its appropriate primary cortex brain region and then, through higher order processing, converged with other sensory modalities to create a more cohesive cognitive stimulus (Thompson et al., 1963). More recent discoveries suggest that the sensory modalities converge much sooner than this (Small et al., 2013). The piriform cortex, a structure within the primary olfactory cortex known to encode for odor memories (Meissner-Bernard et al., 2019), was found to contain neurons that selectively respond to taste (Small et al., 2013). Single neurons in the primary olfactory cortex of 19 rats were found to respond to taste solutions to the tongue (Small et al., 2013). This suggests that there is direct communication between sensory systems. That is, crossmodal bias occurs through exchanges of information between primary sensory systems.

Figure 3. Earlier models suggested a convergence pathway similar to (A) but findings from Small et al. (2013) suggest a schematic more like (B).

Immediately after telling my boyfriend about my cathartic wine tasting, he pronounced that sommeliers are simply full of it. In fact, in a study done by Castriota-Scanderbeg et al. (2005) investigating the differences between sommeliers and naïve research subjects, it was found that sommeliers actually have more refined olfactory and taste perception sensitivity (Castriota-Scanderbeg et al., 2005). 7 male sommeliers and 7 males with no wine tasting training were given either wine or glucose and a subsequent functional magnetic resonance imaging (fMRI) was performed. The left insula, orbit-frontal cortex, and bilateral dorsolateral prefrontal cortex were significantly more involved in wine tasting of sommeliers in comparison to naïve subjects (Castriota-Scanderbeg et al., 2005). Modulated by expertise, these regions represent areas where taste and olfactory stimuli converge and therefore give rise to the representation of flavor (Castriota-Scanderbeg et al., 2005). Moreover, in comparison to glucose, the wine elicited a neural response after the initial taste period which the researchers attribute to the presence of olfactory stimulus (Castriota-Scanderbeg et al., 2005) giving more evidence to the influence of smell on taste.

Over the past 50 years, the well-established organization of sensory systems has been dissolved through discoveries of sensory-sensory connectivity and the influences of one sensory modality on another. So, next time you uncork a nice bottle of wine, or dare I say, screw the top of your $3 bottle, recognize the convergence of your senses.

 

References

Baylis LL, Rolls ET (1994) Gustatory, olfactory, and visual convergence within the primate orbitofrontal cortex. Journal of Neuroscience 14(9):5437-5452. doi: 10.1523/JNEUROSCI.14-09-05437.1994

Castriota-Scanderbeg A, Hagberg GE, Cerasa A, Committeri G, Galati G, Patria F, Pitzalis S, Caltagirone C, Frackowiak R (2005) The appreciation of wine by sommeliers: a functional magnetic resonance study of sensory integration. NeuroImage 25(2):570-578. doi: 10.1016/j.neuroimage.2004.11.045

Rolls ET, Deco G (2002) Computational neuroscience of vision. Oxford University Press, Oxford (2002)

Small DM, Veldhuizen MG, Green B (2013) Sensory neuroscience: taste responses in primary olfactory cortex. Current Biology 23(4): R157-R159. doi: 10.1016/j.cub.2012.12.036

Thompson RF, Johnson RH, Hoopes JJ (1963) Organization of auditory, somatic sensory, and visual projection to association fields of cerebral cortex in the cat. Journal of Neurophysiology 26(3): 43-364. doi: 10.1152/jn.1963.26.3.343

Verhagen JV, Engelen L (2006) The neurocognitive bases of human multimodal food perception: sensory integration. Neuroscience and Biobehavioral Reviews 30(5):613-650. doi: 10.1016/j.neubiorev.2005.11.003

Photos

Figure 1 and 2 were taken by me

Figure 3: Small DM, Veldhuizen MG, Green B (2013) Sensory neuroscience: taste responses in primary olfactory cortex. Current Biology 23(4): R157-R159. doi: 10.1016/j.cub.2012.12.036