Numerous studies show that social cues are processed preferentially by the human visual system and that perception of communicative intentions, particularly those self-directed, attracts and biases attention. However, it is still unclear when in the temporal hierarchy of visual processing communicative cues exert impact on perception and whether their effects are automatic or volitional. Therefore, in the present study, we used electroencephalography (EEG) to investigate the pattern of neural activity associated with processing communicative and individual gestures. Participants (N = 24) were shown animations depicting either biological (BM) or scrambled motion (SM) and were asked to categorize them accordingly. Additionally, BM depicted either communicative or individual actions. The results showed that while early components (N1, N2) are sensitive to differences between BM and SM, the differentiation of neural activity related to the type of action performed by point-light agent (individuals vs. communicative) is observed only for late components such as posterior late positive potential (>500 ms). The findings of the current study show that even in the absence of any top-down effects, social intentions produce long-lasting attentional effects at the later stages of stimuli processing.
Keywords: Biological motion; communicative intention; late positive potential; social interaction.