Duration, Sequence and Beat Perception across Modalities

Certain rhythmic sequences spontaneously induce the perception of a beat: a psychologically salient pulse that marks equally spaced points in time. However, individuals vary considerably in beat perception ability. This variability may arise from variability at multiple levels of a perceptual timing hierarchy of durations, sequences and beat. Specifically, variability could reflect individual differences in basic duration perception, even for single intervals, as single intervals are the building blocks for sequences. Alternatively, it could relate to differences in the timing or recall of temporal sequences despite good single-interval timing, as a sequence needs to be encoded accurately for an underlying beat to be perceived. Finally, it is possible that beat perception variability is specifically related to listeners' ability to extract the beat from temporal sequences. To determine whether evidence supports this three-level perceptual timing hierarchy, and how beat perception ability relates to single-duration and sequence perception ability, we tested performance on single-interval timing, nonbeat sequence timing, and beat sequence timing tasks using a three-alternative forced-choice paradigm. Moreover, we presented both visual and auditory stimuli to determine whether perceptual abilities across sensory modalities are related or independent. We applied a k-means clustering algorithm to partition participants based on task performance. The results support the three-level perceptual hierarchy in the auditory modality, and that beat perception deficits can arise from deficits at any level of the hierarchy. However, the hierarchy did not hold for the visual modality, suggesting rhythm and beat perception vary across modalities.