Crossmodal Activation of Visual Object Regions for Auditorily Presented Concrete Words

Abstract

Dual-coding theory (Paivio, 1986) postulates that the human mind represents objects not just with an analogous, or semantic code, but with a perceptual representation as well. Previous studies (eg, Fiebach & Friederici, 2004) indicated that the modality of this representation is not necessarily the one that triggers the representation. The human visual cortex contains several regions, such as the Lateral Occipital Complex (LOC), that respond specifically to object stimuli. To investigate whether these principally visual representations regions are also recruited for auditory stimuli, we presented subjects with spoken words with specific, concrete meanings (‘car’) as well as words with abstract meanings (‘hope’). Their brain activity was measured with functional magnetic resonance imaging. Whole-brain contrasts showed overlap between regions differentially activated by words for concrete objects compared to words for abstract concepts with visual regions activated by a contrast of object versus non-object visual stimuli. We functionally localized LOC for individual subjects and a preliminary analysis showed a trend for a concreteness effect in this region-of-interest on the group level. Appropriate further analysis might include connectivity and classification measures. These results can shed light on the role of crossmodal representations in cognition.