Perceiving temporal structure within and between the senses: A multisensory/crossmodal perspective.

The literature demonstrates that people perceive temporal structure in sequences of auditory, tactile, or visual stimuli. However, to date, much less attention has been devoted to studying the perception of temporal structure that results from the presentation of stimuli to the chemical senses and/or crossmodally. In this review, we examine the literature on the perception of temporal features in the unisensory, multisensory and crossmodal domains in an attempt to answer, among others, the following foundational questions: Is the ability to perceive the temporal structure of stimuli demonstrated beyond the spatial senses (i.e., in the chemical senses)? Is the intriguing idea of an amodal, or supramodal, temporal processor in the human brain empirically grounded? Is the perception of temporal structure in crossmodal patterns (even) possible? Does the ability to perceive temporal patterns convey any biological advantage to humans? Overall, the reviewed literature suggests that humans perceive rhythmic structures, such as beat and metre, across audition, vision and touch, exhibiting similar behavioural traits. In contrast, only a limited number of studies have demonstrated this ability in crossmodal contexts (e.g., audiotactile interactions). Similar evidence within the chemical senses remains scarce and unconvincing, posing challenges to the concept of an amodal temporal processor and raising questions about its potential biological advantages. These limitations highlight the need for further investigation. To address these gaps, we propose several directions for future research, which may provide valuable insights into the nature and mechanisms of temporal processing across sensory modalities.