Name:Zhaleh Mohammad Alipour

School/Affiliation:University of Western Ontario

Co-Authors:Dr. Jessica Grahn, Dr. Blake Butler

Virtual or In-person:In-person

Abstract:

In musical rhythms, humans spontaneously perceive a beat: a psychologically salient pulse that marks equally spaced points in time. Although humans can perceive, produce, and synchronize with a musical beat, individuals vary in beat perception ability. This study investigates the reasons for poor performance in perceiving the beat. One possibility is poor timing, even for single durations. Another is poor timing of, or memory for temporal sequences, with preserved single duration timing. A third is a selective deficit in perceiving or extracting the beat, but preserved timing and sequencing ability. To determine whether the evidence supports this 3-level perceptual hierarchy, we tested performance on “single duration timing”, “non-beat sequence timing”, and “beat sequence timing” tasks. We also examined how this relationship differed for different modalities (including audition and vision). 101 people (41 males and 60 females) were recruited through the CloudResearch platform, and we used the three-alternative forced choice discrimination task to investigate discrimination ability for the three timing levels of single durations, non-beat, and beat sequences. We applied the k-means clustering algorithm to partition participants based on their performance. The results show that the 3-level perceptual hierarchy is supported for the auditory modality but not for the visual modality. This finding suggests that beat perception and timing in the visual domain rely on different mechanisms than those in the auditory domain.