Author Archives: Maxwell Gerard Farina

Put on Your Dancing Shoes

Last Friday, we had the incredible opportunity to be a part of Paris’ Fête de la Musique, a celebration of music in all its forms. Starting in the evening and lasting well into the next morning, the festival brings thousands of musicians to hundreds of bars, clubs, courtyards, and street corners in all twenty of the arrondissements of the city. Everyone crowds the streets to celebrate, and there is music wherever you turn; oftentimes musicians are so close that you can actually hear multiple performances simultaneously. As the night went on, we found ourselves immersed in an environment filled with new friends, loud music, and lots of dancing. We danced alongside the Parisians to club electronica, gritty rock, solo vocals, drum circles, and even American pop. The instinct to move in synchrony with the music was not only consistent across genres, but also ubiquitous among individuals. This final post of our trip aims to explore the profound and fascinating link between dancing and music.

Venues for Fête de la Musique 2013. A better question: where isn't there music?

One prominent theory to explain movement coordinated with music suggests that this type of synchronized movement simulates music production itself, which may have evolved as a method of social bonding (Levitin and Tirovolas, 2009). The importance of music as a type of honest, yet generalized, form of communication may have lead to activation of reward systems in the brain upon not only personal production of music, but imitating the production of music present in the environment. I personally tend to disagree with this hypothesis. Though I find actual production of music to be the most enjoyable of all, I do not necessarily feel that fingering along accurately to a piano lick is any more rewarding than flailing my entire body to the beat. Though my own personal experiences prove nothing, this theory of pleasure being derived from musical imitation tends to draw skepticism in literature on the topic, as it is not even clear that music is an evolutionary adaptation in the first place.

One of the festival's larger venues.

More recent research, however, takes a different approach to the question. Testing of both musicians and non-musicians suggests that moving to a beat actually enhances perception of the metrical structure (Su and Pöppel, 2012). The experiment that demonstrated this was actually fairly straightforward. Test subjects listened to rhythmic excerpts that maintained a constant tempo throughout and were instructed either to move to the music (e.g. foot-tapping, head-nodding, or body-swaying) or were told to sit still while they listened. Participants were also told to indicate what they felt to be the beat of the music by tapping their finger on the table in front of them. Once the music began, the researchers would occasionally silence the music at random on key beats, though subjects were instructed to continue tapping during these “dropped” beats. The accuracy of the placement of the dropped beat and overall consistency of tapping throughout the sequence were measured and compared between test groups, and researchers found significant improvements in both measures when the subjects were moving versus remaining still. Interestingly, this finding held true regardless of what the consistent tempo was. Whether at 60 beats per minute (the tempo of a very slow ballad) or at 210 bpm (well above the vast majority of music), synchronized movement enhanced understanding of the rhythmic structure.

Further characterization of movement-induced enhancement of beat perception found that this effect is only true of auditory stimuli, and in fact, movement impairs timing extraction in equivalent visual tasks (Iordanescu et al., 2013). This finding implies that synchronized movement may somehow bear a particularly special connection to our interpretation of sound. Could the fun of dancing arise from its ability to increase our sensitivity to rhythmic patterns? That may be what the research suggests. From soon after birth, humans have an innate desire for information and, quickly thereafter, an insatiable need to categorize (Perlovsky, 2010). This ability and, in fact, craving to classify our world has been referred to as the “knowledge instinct,” and this may explain why we so readily appreciate a more intensified and obvious pattern in our aural environment.

All of the rhetorical questions, personal musings, and references to psychological theory in this post are a testament to the real conclusion to this discussion: nobody actually knows why we like dancing so much. Indirect experiments and conveniently intuitive theories of selective pressure can only provide so much insight into the issue; so while science works on solving this highly urgent question, just enjoy the music and keep on dancing.

Dancing (if you can call it that) in Homo sapiens.


-Max Farina



Iordanescu L, Grabowecky M, Suzuki S (2013) Action enhances auditory but not visual temporal sensitivity. Psychonomic Bulletin & Review 20: 108-114.

Levitin DJ, Tirovolas AK (2009) Current advances in the cognitive neuroscience of music. Annals of the New York Academy of Sciences 1156: 211-231.

Perlovsky L (2010) Musical emotions: functions, origins, evolution. Physics of Life Reviews 7: 2-27.

Su YH, Pöppel E (2012) Body movement enhances the extraction of temporal structures in auditory sequences. Psychological Research 76: 373-382.

The Broken Escalator Effect (It’s Real)

Every day we take the Paris Metro and RER to and from class. It’s a relatively painless trip, except when there’s a strike going on (which has been almost every day). One day last week, as our motley crew filed through our favorite station, Châtelet, to transfer trains, we reached our favorite stretch of the station: the moving walkways. I approached the walkway without hesitation, took a step onto the belt, and immediately felt myself jolted awake by a sense of falling. As it turned out, the moving walkway was broken that day, and pedestrians were just using it as a normal path. I followed suit and laughed silently at how funny I must have looked to anybody who saw me nearly fall on my face.

Our favorite Metro stop

Later that afternoon, on the return journey, I’d had ample time to wake up during the day. As we approached the same collection of moving walkways, I made sure to take note of the functionality of the machines. They were all still broken, but I decided to follow the crowd and walk along one of the belts anyway. This time, I approached, took a step, and felt jolted again! I was shocked at my brain’s miscalculation despite my conscious awareness that the walkway was stationary. I presumed that it had to be some sort of perceptual memory that I had for moving walkways. Perhaps because reality wasn’t matching up with what my brain had learned to be true of “people-movers” countless times before, my mind was having trouble adjusting. I decided it was worth a search in the literature when I got home.

No "broken escalator effect" here

What I found was not only reassuring for my vestibular system, but also immensely interesting. There is an extensive collection of scientific research on what has been called the “broken escalator phenomenon,” (Reynolds and Bronstein, 2003). Evidently, the effect is more evident on moving walkways, but because nobody knows what to call them, the original authors of the phrase decided to go with escalator instead. Once the phenomenon became well known as a common occurrence in city-dwellers, researchers sought to describe what was actually happening to cause this “feeling of uneasiness” despite absolute consciousness of the fact that the conveyor was not moving

First, experimenters had subjects walk on a short, stationary moving walkway a few times while measuring walking speed, postural sway, and muscle contraction (Reynolds and Bronstein, 2003). Afterwards, the experimenters turned on the walkway and had the same subjects board the machine. Not surprisingly, subjects made several physical changes as they got used to the moving version, but the most significant change observed was in the actual velocity of movement just prior to boarding. Naturally, the subjects increased their pace by .3 m/s in order to minimize being jerked by the belt. This is similar to what happens to us in everyday life. We encounter a majority of moving walkways in their “on” position, and we become accustomed to increasing pace, leaning forward, and flexing our leg muscles as we approach them. Next, the researchers informed the subjects that the walkway would be turned off, and in fact, they could see so for themselves. When they approached the walkway this time, all subjects stumbled, and many were shocked or laughed at the occurrence. Analysis of the physiological data showed that approach velocity, trunk lean, and muscle contraction took place at levels in between normal walking values and the values seen when subjects were accustomed to the moving walkway. It seemed that the brain was confused by seeing a normally moving pathway in a motionless state, and addressed the situation by “hedging its bets” so to speak. Interestingly, repeating a second trial with the “off” walkway shows no signs of distress. The brain learns quickly to adopt normal walking motor programs for the motionless walkway. Further studies have shown that skin conductance also increases just prior to experiencing the “broken escalator phenomenon,” implying that subconscious, fear-based mechanisms are at play (Green et al., 2010). This may explain why the hiccup occurs even when one consciously recognizes that normal walking will suffice.

Primary motor cortex, where the researchers stimulated.

Given that this phenomenon is strikingly similar to the lack of balance that many neurological disease patients experience, further studies aimed to find ways to modulate to the occurrence (Kaski et al., 2012). Recently, researchers tried this using a technique called transcranial direct current stimulation (tDCS), which is a lot like connecting a battery to your skull, except it’s scientific. Subjects went through the same experimental procedure as in the first study, but just before had a small anodal current passed through their brain for 15 minutes before the moving platform phase of testing. The researchers targeted the primary motor cortex, an area of the brain responsible for executing movement and storing motor memories, or the actual plans that the body uses to coordinate movement. The researchers believed that the broken escalator effect occurred due to an inability to suppress the brain’s default “moving walkway motor plan,” so activating primary motor cortex would cause the phenomenon to become even more extreme. Indeed, the subjects who received the electrical stimulation showed a larger broken escalator effect and took more trials to adjust to the stationary pathway than control subjects who received no stimulation. Though the nature of the experiment did not necessarily prove that the broken escalator effect is due to overactive motor memory, the results are significant in that they show it is possible to manipulate gait and motor problems with relatively simple technology. tDCS is fairly cheap and straightforward compared to other similar technologies, and its lack of precision actually lends itself nicely to working with the distributed neural systems of locomotion. Though this study used tDCS to worsen a locomotor problem, this same system may soon become a useful tool in neurological diseases that show locomotor symptoms such as stroke, Parkinson’s multiple sclerosis, and Alzheimer’s disease.


-Max Farina



Reynolds RF, Bronstein AM (2003) The broken escalator phenomenon. Experimental Brain Research.

Green DA, Bunday KL, Bowen J, Carter T, Bronstein AM (2010) What does autonomic arousal tell us about locomotor learning? Neuroscience 170: 42-53.

Kaski D, Quadir S, Patel M, Yousif N, Bronstein AM (2012) Enhanced locomotor adaptation aftereffect in the “broken escalator” phenomenon using anodal tDCS. Journal of Neurophysiology 107: 2493-2505.

Baroque Music at Sainte Chapelle


Last week, we took a group trip to Sainte Chapelle, a Gothic church in the heart of Paris. Though many visit the church to admire the magnificent collection of 13th century stained glass and extensive collection of Christian relics, we were there to hear an authentic Baroque music concert. Much of the hour-long concert featured a trio of harpsichord, violin, and recorder, but at one point, the recorder player took a solo and switched from playing the soprano version of the instrument to the higher-pitched sopranino. After the recorder player began his solo on the stage, he proceeded to wander throughout the entire chapel—through the audience, along the walls of the chapel, and at one point even directly behind the seating area.

When I said "heart of Paris," I meant it.

As the soloist walked around far behind me, I noticed that I was able to identify where the sound was coming from even though I was facing the opposite direction. I immediately remembered a lecture from neurobiology class that covered the neural mechanisms involved in sound localization. The process depends on the fact that our brain has the ability to compare inputs from both ears. When sound emanates from a source, it usually is not exactly the same distance away from each ear, so when the sound reaches both ears, the difference is calculated and converted into an angle to the direction of the sound (Grothe, 2003). Oftentimes, the difference between arrival at each ear can be as little as 10 microseconds (that’s 1/100,000th of a second)!. This calculation of interaural time difference (ITD) occurs in the medial superior olive, a collection of cells in the brainstem.

Basis of interaural time difference

I was curious, though, if the same process was taking place during the concert. I remembered that the ITD calculations are particularly effective for low frequency sounds, certainly lower than the high-pitched sopranino recorder (Devore and Delguette, 2010). Additionally, I imagined that the tall ceiling and compartmentalized roof, typical of Gothic architecture, would create echoes that further complicate the use of ITD to localize sound. I looked into the matter, and found an article that attempted to explore how the brain’s ability to localize sound is affected by reverberation (Devore and Delguette, 2010). The researchers thought that the lateral superior olive, which uses interaural level difference (ILD) to localize sound rather than ITD, would be preferentially involved in sounds distorted by reverberation. In order to test this hypothesis, the experimenters used a technique called in-vivo electrophysiology, which places a collection of small recording electrodes into the brain and is able to isolate activity from single brain cells in awake, behaving subjects. Once the electrodes were in place, the subjects (in this case, rabbits) were exposed to a variety of auditory stimuli. The stimuli varied in direction, pitch, and reverberant nature so that the researchers could determine which pathways were in use in different situations. They found that the brain relies more heavily on ILD than ITD in reverberant situations, particularly for high-frequency pitches.

Beautiful? Yes. Reverberant? Absolutely.

While researching sound localization, I stumbled across another article that I found to be particularly interesting. I have always been amazed by conductors’ abilities to identify a single individual who misses a note in a 70-person ensemble. Researchers found that the constant exposure to wide field multi source sound environments experienced by conductors actually changes the way that conductors’ brains process the information (Münte et al., 2001). Not surprisingly, conductors outperformed both non-musical controls and pianists in accuracy of sound localization, but interestingly, recordings of brain activity during the task revealed that all groups utilized identical regions of the brain. This finding led the researchers to suggest that the intensive training and exposure that conductors receive simply trains their brain to more effectively use the sound localization pathways that we all use everyday. Take home message: the phrase “mental exercise” has a good deal of validity to it.

 – Max Farina


Works Cited:

Devore S, Delguette B (2010) Effects of reverberation on the directional sensitivity of auditory neurons across the tonotopic axis: influences of interaural time and level differences. Journal of Neuroscience 30: 7826-7837.

Grothe B (2003) New roles for synaptic inhibition in sound localization. Nature Reviews Neuroscience 4: 540-550.

Münte TF, Kohlmetz C, Nager W, Altenmüller E (2001) Neuroperception: Superior auditory spatial tuning in conductors. Nature 409.