Grey matter volume in the right Angular Gyrus is associated with differential patterns of multisensory integration with ageing

Abstract

Multisensory perception might provide an important marker of brain function in ageing. However, the cortical structures supporting multisensory perception in ageing are poorly understood. In this study, we compared regional grey matter volume in a group of middle-aged (n = 101; 49 – 64 years) and older (n = 116; 71 – 87 years) adults from The Irish Longitudinal Study on Ageing using Voxel Based Morphometry. Participants completed a measure of multisensory integration, the Sound-Induced Flash Illusion, and were grouped according to their illusion susceptibility. A significant interaction was observed in the right Angular Gyrus; in the middle-aged group, larger grey matter volume corresponded to stronger illusion perception whilst in older adults larger grey matter corresponded to less illusion susceptibility. This interaction remained significant even when controlling for a range of demographic, sensory, cognitive and health variables. These findings show that multisensory integration is associated with specific structural changes in the ageing brain and highlight the Angular Gyrus as a possible “cross-modal hub” associated with age-related change in multisensory perception.