Music and Neurosciences IV,  Rhythm

Day 2 – Rhythm and Meter learning

Day 2 in Edinburgh began sunny and fresh.  Dr Mullensiefen and I found a little cafe for breakfast that served a very reasonable and tasty bowl of Scottish oat porridge. Just the thing to keep your energy levels up for a long morning of fascinating talks!  This cafe, just off the Royal Mile, (called ChocolateSoup ) would become the regular breakfast haunt for the majority of the MMB research group during the conference. Who needs an expensive and tired re-heated hotel breakfast!?

The second day of the conference began with a keynote from Professor Alan Baddeley . I have to admit, dear reader, that I practically bounced to the conference venue such was my level of excitement. I am incredibly biased, I know, since Alan was my PhD supervisor. But nevertheless I think he is one of the best speakers in the World (on any subject!).

He is a calm and entertaining presenter who manages to appear friendly and approachable while still exuding a powerful air of scholarly force. You can just tell he has a vast array of knowledge and understanding on the topic of memory, and yet he still enjoys learning and expanding his ideas. It is always a treat to be taken on a journey by him through the development of the working memory model.

He was also kind enough to mention my PhD work on music and working memory at the end of his talk, a situation that had me simultaneously beaming with pride on the inside and sinking down into my chair on the outside. What an honour. I shall treasure that moment.

Alan’s talk was followed immediately by a symposium on rhythm and meter learning. Now, I will confess here and now that in the past I have not been all that interested in rhythm. I enjoyed hearing about developments in the field, don’t get me wrong, and I thought the work was important – it was just not something I would typically go out of my way to read up on during my busy days. But this symposium was very interesting; all three speakers had great ideas about how we learn about rhythm. On reflection I can see that rhythm is perhaps unfairly overlooked by ‘tone happy’ people such as me! I have made an undertaking to read more on the subject in the future. To give a quick summary of each talk:

1)      Devin McAuley   – Neural basis of individual differences in beat perception

Devin began by describing rhythm as a temporal pattern of elements that most humans are able to tap along to quite naturally. Our movements to rhythm reveal our ability to perceive one crucial element within music; the beat or ‘pulse’.

How do we do this? Devin presented his leading hypothesis which is built on a lot of the work with Jessica Grahn and is called the Beat Based Advantage (BBA). The BBA is a hallmark of a successful rhythmic encoding system, which Devin argued is based on a dual process framework with distinct neural circuitry for beat based processes and interval based processes.  Some of the neural systems involved in the beat system include the basal ganglia, the supplementary motor areas and the premotor areas.

He then showed a number of impressive studies looking at individual differences in the BBA. Grahn and Brett (2009) showed that the BBA is eliminated in Parkinson’s disease, a condition which impacts severely on the function of the basal ganglia. The BBA in control participants however, depends strongly on tempo – if you slow down rhythms then people perform at the same level of Parkinson’s patients.

Individual differences in beat sensitivity have also been nicely demonstrated with the implied beat paradigm (Grahn and McAuley, 2009 in Neuroimage). Beat sensitivity is another area of the rhythm system that is impaired in Parkinson’s, once again underlining the important role of the basal ganglia.

2)      Henkjan Honing – Is hierarchy in rhythm perception learned or emergent?

Henkjan is a fellow blogger so while I remember I invite you to visit his site. He has done some of the most intricate work on rhythm perception and has successfully demonstrated that not only are hierarchical representations of rhythm formed pre-attentively (as indexed by the response of the mis-match negativity) , but also that this can be detected in 2-3 day old neonates.

Here is a picture of these tiny little ones in the mini EEG set up sleeping away – so cute! But it is fascinating that we can detect the brains response to rhythm in tiny babies and that they don’t even have to be awake for this to happen. In fact they are tested after a nice big meal when they are snoozing away happily!

Another thing that Henkjan outlined that seemed very important to him (and was echoed elsewhere by other speakers such as Peter Vuust) was that they get bigger EEG effects with more realistic, ecologically valid and complex music stimuli. It is of course still valid and interesting to use simple stimuli but we should not forget that there must be a limit to the conclusions we can draw if our effects can’t be demonstrated with real music – after all, that is where our interests lie!

3)      Erin HannonRhythm learning through listening

Erin is interested in how young children build upon the neural responses demonstrated by Henkjan to develop the complex understanding of rhythm and beat that was demonstrated by Devin. She asked the question, are there sensitive periods for rhythm learning?

The best evidence for sensitive periods in learning comes of course from studies of second language learning. Surprisingly perhaps, there is not so much evidence relating to a similar period for music (although we do know about the speed of neural changes in the young and the development of absolute pitch).

The issues with tracking musical learning are of course the content of the lessons and the effort put in place by parents outside lessons. So Erin decided not to use lessons but instead just to use listening. How well do children pick up on foreign rhythms with mere exposure?

She tested American children (4-12 years) and adult’s (18 years and older) discrimination of simple, familiar rhythms (Western) and complex-meter folk music from Bulgaria which typically use a 7/8 rhythm as opposed to a 2/1. She had a great task for the kids in order to test their rhythm perception involving a cartoon lion and his friends!  Before exposure everyone was better on the Western rhythms but as the number of listening sessions increased the younger children started to show a loss in their asymmetry; they were becoming better at perceiving the Balkan rhythm.

This data suggests that maybe there is a sensitive period for learning about rhythms from listening alone. However, there are of course a number of issues that Erin wanted to make clear. We still don’t know whether young children listen in a different way (e.g. more attentively by nature) and whether their listening style could be mimicked by adults to their benefit.  She tried a recognition test and found that everyone performed about the same, suggesting that no-one was ‘slacking’ in their exposure, but there may be levels of listening that go beyond that measured by a simple recognition task.

Overall, very interesting work I am sure you will agree and once again I hang my head in shame for not paying more attention to this area in the future. It is great to see this work being done and such interesting breakthroughs in our understanding of how our ‘natural’ rhythm ability develops and can decline as we age.