Rhythm Perception and Production Workshop RPPW2015

Royal Tropical Institute

After 10-year hiatus, I attended the Rhythm Perception and Production Workshop (RPPW), that this time was organised in Amsterdam. Since the last time, this conference series has changed a lot: the range of topics and approaches was huge, spanning from animal rhythmic abilities to gait, from Parkinson’s to language, from music and dance to rowing, with lots of neuroscience papers presented.

I like these smaller meetings with fewer participants. Having all talks in plenary sessions means that you can effectively see everything there is to offer. And you get to talk to most people attending, and you can organise nice conference dinners with jam sessions because the crowd is small enough to fit in an intimate venue.

There were a lot of interesting talks, but here are notes of a few that I found fascinating:

Carel J. ten Cate was the first keynote speaker, and his talk on animals and rhythms was very interesting. He argued that studying animal rhythm perception helps understand their rhythmic abilities, as production studies are often problematic due to motivation issues etc. It was a nice overview on bird studies, especially.

Laura Cirelli had studied whether moving to music is a social experience for 14 mth old infants, by bouncing babies and then getting them do a pro-sociality test (helping pick up clothes pins for the experimenter). They showed that synchronised bouncing boosted helpfulness, but this didn’t extended to new people; in older children and in adults the pro-social effects often generalise beyond the person whom participants had been syncing with.

Jessica Grahn kicked off the second day with her keynote titled “Rhythm Perception and the Motor System”. The talk was excellent, as her talks always are, and I find her research inspiring and insightful. No wonder so many people now use the same types of stimuli as she did in Grahn & Brett 2007, where they compared perception and production of simple metric, complex metric and non-metric rhythms. After studying Parkinson’s patients, she has now been using transcranial direct current stimulation (tDCS) to study the effects that the supplementary motor area (SMA), premotor cortex (PMC) and the cerebellum have in beat perception. It looks that stimulation has very different effects on these areas, with SMA stimulation having an effect on both, beat-based and nonbeat rhythms, PMC not being affected and for cerebellum, any type of stimulation adversely affecting beat perception.

In the second part of her talk, she showed a great graph on individual differences in rhythm abilities: in a rhythm reproduction task (tapping a rhythm that you have just heard), some participants performed at the ceiling, with 100% correct, whereas some participants were at the floor, not managing to get a single one right. And this was with relatively loose criteria of success. A good reminder to everyone who mainly studies music students…

Birgitta Burger showed new dance data from Jyväskylä: in her talk she showed that event density in the music predicts how participants can synchronise with the music.

Mark Elliott gave a talk on synchronisation in a violin trio. The study was based on the string quartet study conducted earlier in Birmingham (by Alan Wing et al.). In this experiment, they had three violinists perform Frere Jacques in a number of conditions. First solo, to see how fast they’d perform it if it were just for them to decide, then together with others in unison and finally in canon. In turn, each participant was assigned to be the leader who got to decide what the tempo would be. They showed that the spontaneous rates with which the players performed the piece when playing it solo often, but not for everyone, predicted the trio tempo. In one trio the solo tempi matched the ensemble tempi perfectly, in another there was cross-over, so that fastest soloists lead the trio in the slowest tempi and vice versa. In the third trio there was almost no variance in either the solo or trio tempi. They also looked at how the trio synchronises, and who adjusts their timing in response to the others most. This analysis, based on the linear error correction model showed that the instruction to lead changed the gain parameters in the trios, showing that even in this simple song, and in an ensemble where everyone plays the same instrument, the leader assignment has an effect on the group timing, not just in choosing the tempo but also in time-keeping.

Peter Keller was again involved in a large number of papers, including a study looking at individual differences in sensori-motor synchronisation, looking at how preferences and performance are linked. Participants had rated synthesised music ensemble performances where the error correction parameters in the group were varied, and then performed a range of tapping tasks to show how they themselves synchronise.

Rainer Polak was also responsible for many studies, as he had collected a fantastic data set of Malian jembe drumming, and this data had then been analysed from a number of perspectives, looking at rhythmic patterns, error correction and influence within the ensembles.

In my own session, Laura Cuijpers presented a study on synchronisation in rowing. They had applied motion capture to two rowers on ergometers on slides, and gate sensors on a double scull on the water. They had varied the stroke rate and investigated how well the pair synchronises. Increasing the rate improved synchrony, although at the same time increasing the rate very quickly also made the sync unstable and fall apart. One of the interesting bits was their ongoing study on a double scull where the rowers take strokes in alternating rhythm and not synchronously as in a normal boat. It looked absolutely crazy! I’m very much looking forward to those results!

Lauren Hadley presented a TMS study on turn-taking piano duets. Participants had rehearsed one part of 4 different piano duets, in two of them they had seen the other part as well, in two only their own part, so that the partner’s part would then come as a surprise. The pieces were such that the two pianists took turns, performing a couple of bars in turn. One part was always played by a computer, so for the participants this was a solo study, and they only needed one hand to perform their part.

A double pulse TMS was delivered to the ipsilateral pre-motor cortex, at different times before their turn, in half the trials the TMS was real, in half a sham stimulation was administered. The role of the PMC was assessed by looking at the response accuracy, whether the participant played their turn in the correct timing. With the early TMS, when the participant knew both parts, TMS was found to be disruptive. in contrast, when the participant only knew their own part, it was the TMS that was timed closer to their start that was found to disrupt their timing. Her conclusion was that earlier TMS disrupts planned responses, while TMS administered later interferes with unplanned responses.

Dirk Moelants presented perhaps the most novel study in the conference: “Temporal cueing in rhythm performance: synchronizing by sniffing”. These sniffs are the fast inspirations of air that serve as cues for starting the piece in an ensemble. Moelants and Coorevits had set up an experiment to look at how they code for tempo, and how they are related to the timing of the first note. In a rock or jazz band, the drummer can count the start, but this is “not allowed” in classical music. Rather, a visual gesture is given by the conductor or the leader of the ensemble, and this sniff is the auditory version that often accompanies this gesture. Usually, the performers will have a very good idea of the tempo, as they have rehearsed the piece together, but in the experiment they had to clap a rhythm with a partner and this was not so easy. The first claps were often unsynchronised. The length of the sniff correlated with the tempo, with slower tempi linked to longer sniffs.

All in all it was a very nice event, with lots of old friends to meet, and new ones to make. Conveniently, we were not the only cool people in the Netherlands at the time: the Tour de France started in Utrecht two days before the RPPW, and on the Sunday before the meeting, the race was going through Rotterdam. With cycling enthusiast friends, we took the train from Amsterdam to Rotterdam to see the riders flash by. You can check out this little photo and video summary of our excursion, as well as the seminar here.

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