Visual motion assists in social cognition

• Published in: Proceedings of the National Academy of Sciences - PNAS 2020-12, Vol.117 (50), p.32165-32168
• Main Authors: Guterstam, Arvid, Graziano, Michael S. A.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Attention - physiology; Biological Sciences; Brain; Cognition; Cognitive ability; Correlation analysis; Facial Expression; Facial Recognition - physiology; Female; Humans; Information processing; Male; Medicin och hälsovetenskap; Middle Aged; Motion detection; Motion Perception - physiology; Object motion; Orientation behavior; Photic Stimulation - methods; Psychology; Signal processing; Social Cognition; Social interactions; Streaming; Theory of Mind; Visual signals; Young Adult
• ISSN: 0027-8424; 1091-6490; 1091-6490
• DOI: 10.1073/pnas.2021325117

Recent evidence suggests a link between visual motion processing and social cognition. When person A watches person B, the brain of A apparently generates a fictitious, subthreshold motion signal streaming from B to the object of B’s attention. These previous studies, being correlative, were unable to establish any functional role for the false motion signals. Here, we directly tested whether subthreshold motion processing plays a role in judging the attention of others. We asked, if we contaminate people’s visual input with a subthreshold motion signal streaming from an agent to an object, can we manipulate people’s judgments about that agent’s attention? Participants viewed a display including faces, objects, and a subthreshold motion hidden in the background. Participants’ judgments of the attentional state of the faces was significantly altered by the hidden motion signal. Faces from which subthreshold motion was streaming toward an object were judged as paying more attention to the object. Control experiments showed the effect was specific to the agent-to-object motion direction and to judging attention, not action or spatial orientation. These results suggest that when the brain models other minds, it uses a subthreshold motion signal, streaming from an individual to an object, to help represent attentional state. This type of social-cognitive model, tapping perceptual mechanisms that evolved to process physical events in the real world, may help to explain the extraordinary cultural persistence of beliefs in mind processes having physical manifestation. These findings, therefore, may have larger implications for human psychology and cultural belief.