Older Adults with Clinically Normal Sensory and Cognitive Abilities Perceive Audiovisual Simultaneity and Temporal Order Differently than Younger Adults

It is well established that individual sensory and cognitive abilities often decline with older age; however, previous studies examining whether multisensory processes and multisensory integration also change with older age have been inconsistent. One possible reason for these inconsistencies may be due to differences across studies in how sensory and cognitive abilities have been characterized and controlled for in older adult participant groups. The current study examined whether multisensory (audiovisual) synchrony perception is different in younger and older adults using the audiovisual simultaneity judgement (SJ) and temporal order judgement (TOJ) tasks and explored whether performance on these audiovisual tasks was associated with unisensory (hearing, vision) and cognitive (global cognition and executive functioning) abilities within clinically normal limits. Healthy younger and older adults completed audiovisual SJ and TOJ tasks. Auditory-only and visual-only SJ tasks were also completed independently to assess temporal processing in hearing and vision. Older adults completed standardized assessments of hearing, vision, and cognition. Results showed that, compared to younger adults, older adults had wider temporal binding windows in the audiovisual SJ and TOJ tasks and larger points of subjective simultaneity in the TOJ task. No significant associations were found among the unisensory (standard baseline and unisensory SJ), cognitive, or audiovisual (SJ, TOJ) measures. These findings suggest that audiovisual integrative processes change with older age, even within clinically normal sensory and cognitive abilities.