Beat processing is pre-attentive for metrically simple rhythms with clear accents: an ERP study.

Fleur L Bouwer,Henkjan Honing,Titia L Van Zuijen,Blake Johnson

doi:10.1371/journal.pone.0097467

Abstract

The perception of a regular beat is fundamental to music processing. Here we examine whether the detection of a regular beat is pre-attentive for metrically simple, acoustically varying stimuli using the mismatch negativity (MMN), an ERP response elicited by violations of acoustic regularity irrespective of whether subjects are attending to the stimuli. Both musicians and non-musicians were presented with a varying rhythm with a clear accent structure in which occasionally a sound was omitted. We compared the MMN response to the omission of identical sounds in different metrical positions. Most importantly, we found that omissions in strong metrical positions, on the beat, elicited higher amplitude MMN responses than omissions in weak metrical positions, not on the beat. This suggests that the detection of a beat is pre-attentive when highly beat inducing stimuli are used. No effects of musical expertise were found. Our results suggest that for metrically simple rhythms with clear accents beat processing does not require attention or musical expertise. In addition, we discuss how the use of acoustically varying stimuli may influence ERP results when studying beat processing.

Highlights

In music, people often perceive regularly recurring salient events in time, known as the beat [1,2]
The use of such acoustically rich, ecologically valid stimuli could be essential to allow the listener to induce a beat pre-attentively [14], arguably because multiple features in the stimuli carry information about the metrical structure. In these studies a beat was induced by using different sounds for metrically strong and metrically weak positions. While these different sounds may have aided in inducing a beat, this leaves open the possibility that different responses to tones in different metrical positions are due to acoustic differences rather than beat processing [16]
If beat processing is learned behavior, we expect this ability to be influenced by musical expertise and we expect a bigger effect of metrical position on the mismatch negativity (MMN) responses in musicians than in non-musicians

Summary

Introduction

People often perceive regularly recurring salient events in time, known as the beat [1,2]. The latter studies [12,15] used strictly metrical stimuli with variation in the temporal structure of the rhythm, and variation in the timbre and intensity of tones to convey the metrical structure The use of such acoustically rich, ecologically valid stimuli could be essential to allow the listener to induce a beat pre-attentively [14], arguably because multiple features in the stimuli carry information about the metrical structure. If beat processing is learned behavior, we expect this ability to be influenced by musical expertise and we expect a bigger effect of metrical position on the MMN responses in musicians than in non-musicians

Materials and Methods

Results

Discussion