Semantic processing of the audiovisual information in autism: an electrophysiological exploration

Abstract

The aim of this project consists in deeply analyzing several aspects related to semantic processing in autism. In particular, we are going to focus on the semantic processing of the audiovisual stimuli. Since previous works reported mixed findings, we are going to perform an electrophysiological project that could shed some light on these questions. In particular, we are going to carry out three different experiments to clarify several aspects of the phenomenon. In the first study we are investigating if, in ASD children, the semantic processing presented in a unisensory modality is impaired both during the presentation of verbal and nonverbal stimuli. In a second study, we are going to investigate if the semantic processing is compromised when a verbal or nonverbal stimulus has to be integrated in a previous context. Finally, in the third study we are going to investigate the semantic processing in ASD children when stimuli are presented simultaneously. Specifically we are going to compare the electrophysiological responses in a group of ASD scholar-aged children to a control group matched on IQ, and a control group matched on chronological age. We are going to record the event-related potentials to evaluate whether the N400 and late positive potential (LPP) components, two widely studied electrophysiological markers of semantic processing, are differently modulated in ASD children and controls. Therefore, aim of this project is to clarify if the deficit showed by this clinical population is specific to a particular sensory modality (verbal), or concerns to a more generalized impairment in the semantic area. In addition, it could clarify the nature of the audiovisual integration deficit in ASD children.This aspect is particularly critical because the ability to integrate simultaneous stimuli from different sensory modalities may affect the everyday life interactions. We believe that the results of this project may have important implications for diagnosis and treatments of ASD children at an early stage. (AU)