Action recognition of point-light displays presented with semantically (in)congruent auditory stimuli: behavioral correlates

Humans are experts in identifying and understanding others' movements and visual information is often enough to successfully accomplish such tasks. Action-related sounds are also fastly associated and recognized. Still, many studies have demonstrated that the concurrent presentation of these two modalities benefits perception. Herein, we evaluated if congruent/ incongruent action sounds improve/impair recognition of Point-Light Displays (PLD) depicting human actions and if non-human moving PLDs accompanied by action sounds would bias participants into a false perception of human action, as a control, we also presented human and scrambled PLDs accompanied by white noise sound. After each video, participants should answer if it depicted a human figure and as a follow up for affirmative answers they should also name what action the human was performing. Results showed a significantly higher human identification for audiovisual biological congruent when compared to the visual biological paired to auditory noise and to unimodal visual stimuli. Similarly, performance on action recognition was better for the audiovisual biological congruent condition when compared to the unimodal visual stimuli. Lastly, considering the scramble stimuli we found a significant bias towards the identification of a human figure for the visual stimuli paired to auditory noise when compared to the unimodal visual scramble condition. Our findings suggest that adding coincident sounds to a human action visual display impacts human figure identification and action perception in biological PLDs and further, that insignificant sounds might lead to confound perception of non-biological PLDs.