Sensory- and memory-related drivers for altered ventriloquism effects and aftereffects in older adults

The manner in which humans exploit multisensory information for subsequent decisions changes with age. Multiple causes for such age-effects are being discussed, including a reduced precision in peripheral sensory representations, changes in cognitive inference about causal relations between sensory cues, and a decline in memory contributing to altered sequential patterns of multisensory behaviour. To dissociate these putative contributions, we investigated how healthy young and older adults integrate audio-visual spatial information within trials (the ventriloquism effect) and between trials (the ventriloquism aftereffect). With both a model-free and (Bayesian) model-based analyses we found that both biases differed between groups. Our results attribute the age-change in the ventriloquism bias to a decline in spatial hearing rather than a change in cognitive processes. This decline in peripheral function, combined with a more prominent influence from preceding responses rather than preceding stimuli in the elderly, can also explain the observed age-effect in the ventriloquism aftereffect. Our results suggest a transition from a sensory-to a behavior-driven influence of past multisensory experience on perceptual decisions with age, due to reduced sensory precision and change in memory capacity. (C) 2020 The Authors. Published by Elsevier Ltd.

Automated summary

As humans age, the way they exploit multisensory information for decision-making changes, attributed to factors such as reduced precision in peripheral sensory representations, changes in cognitive inference, and declines in memory. Research shows that biases in audio-visual integration differ between young and older adults, with age-related changes in ventriloquism bias being linked to decline in spatial hearing rather than cognitive processes. These findings suggest a shift from sensory-driven to behavior-driven influence of past multisensory experiences on perceptual decisions with age.