Multisensory processing and neural oscillatory responses: separation of visuotactile congruency effect and corresponding electroencephalogram activities

Abstract

By using electroencephalogram, we aimed at identifying the neural oscillations corresponding to two subcomponents of the visuotactile congruency process, facilitation and interference effects. The participants identified the location of the tactile stimulus presented at their index finger or thumb while ignoring simultaneous visual stimuli presented at the same (congruent) or different (incongruent) finger. Significant differences in reaction time were found between the congruent or incongruent condition and the unimodal baseline condition, indicating two different effects of visuotactile interaction. Electroencephalogram results showed significant increases in the γ-band response in the congruent condition and in the θ-band response in the incongruent condition. These results suggest two systems of multisensory interaction.