Cool Logic

Bastiaan van der Weij (ILLC)

Musical metre perception and predictive coding

March 11th at 17:30, in F1.15 (ILLC Seminar Room)

When listening to rhythmical music, we cannot help but to feel the beat. Often, the felt beat is structured so that some beats feel more "strong" than others. This perceived pattern is called metre. Since music has been called the universal language of mankind, you would think that the metre induced by a particular rhythm is the similar for everyone. However, a number of studies indicate that this is not the case. These studies found that the culture you grow up in can influence perception of metre. In other words, previous (passive) exposure influences perception of metre. The idea that perception is influenced by previous experience goes back a long way. Recently this idea has been developed further under the name of predictive coding. Simply put, predictive coding posits that the brain's primary occupation is to predict incoming sensations and that perception arises from the residual prediction error. This is achieved by deriving hierarchical models of the underlying causes of sensations from previous exposure. The principle guiding the construction of these models is minimisation of prediction error. Predictive coding firmly grounds perception in previous exposure and is proposed to be a domain general mechanism. In the talk, I will suggest that predictive coding can explain inter-cultural differences in metre perception. Furthermore, I will introduce a probabilistic model of metre perception, based on the principles of predictive coding, that can be used to test this hypothesis. But before we get to that, I will introduce predictive coding in more detail and illustrate how it is possible that the same rhythm can be perceived in different ways.