Age-Related Effects of Audiovisual Semantic Congruency on Living and Nonliving Object Perception

Abstract

This EEG study investigated age-related effects of irrelevant congruent or incongruent audio semantic information on living and nonliving visual object perception. Twenty-four young adults (YA, Mean Age = 21) and thirty older adults (OA, Mean Age = 72) made speeded orientation judgments to real-world objects in upright or inverted orientations that were presented simultaneously with either a semantically congruent or incongruent sound (e.g., a cow or fire truck presented with the sound 'moo'). Overall, YAs and OAs both responded faster to living compared to nonliving objects in the upright condition, and YAs were overall faster at responding to upright and inverted objects compared to OAs. For living objects, both YAs and OAs displayed a significant effect of semantic congruency on P200 amplitude under the upright condition. For nonliving objects, YAs displayed a significantly more negative N400 amplitude during the incongruent trials compared to the congruent trials under the upright condition. For living objects, YAs displayed a significantly more negative N400 amplitude during the congruent trials compared to the incongruent trials under the inverted condition. In OAs, the N400 amplitude was not modulated by semantic congruency for living nor nonliving objects. Taken together, YAs and OAs show preserved early object processing abilities for canonically represented living objects, and OAs show deficits in later semantic integration.