Audiovisual integration is affected by performing a task jointly

Humans constantly receive sensory input from several sensory modalities. Via the process of multisensory integration, this input is often integrated into a unitary percept. Researchers have investigated several factors that could affect the process of multisensory integration. However, in this field of research, social factors (i.e., whether a task is performed alone or jointly) have been widely neglected. Using an audiovisual crossmodal congruency task we investigated whether social factors affect audiovisual integration. Pairs of participants received congruent or incongruent audiovisual stimuli and were required to indicate the elevation of these stimuli. We found that the reaction time cost of responding to incongruent stimuli (relative to congruent stimuli) was reduced significantly when participants performed the task jointly compared to when they performed the task alone. These results extend earlier findings on visuotactile integration by showing that audiovisual integration is also affected by social factors.