Mixed evidence for the rhythmicity of auditory perceptual judgements in humans.

Abstract

Numerous studies advocate for a rhythmic mode of perception. However, the evidence in the context of hearing remains inconsistent. We propose that the divergent conclusions drawn from previous work stem from conceptual and methodological issues. These include ambiguous assumptions regarding the origin of rhythmicity, variations in tasks and attentional demands, and differing analytical approaches for statistical testing. To address these points, we conducted a series of experiments in which human participants performed auditory tasks involving monaural targets presented against binaural white noise backgrounds, while also recording eye movements. These experiments varied in whether stimuli were presented randomly or required motor initialisation, the necessity of memory across trials, and the manipulation of attentional demands. Our findings challenge the notion of universal rhythmicity in hearing, but support the existence of paradigm- and ear-specific fluctuations in sensitivity and biases at multiple frequencies. The rhythmicity for sounds in the left and right ears appears independent among participants, and the rhythmicity in performance is possibly linked to oculomotor activity and attentional requirements. Overall, these results may help to resolve conflicting conclusions drawn in previous work and provide specific avenues for further studies into the rhythmicity of auditory perception.