Perceiving animacy purely from visual motion cues involves intraparietal sulcus

• Published in: NeuroImage (Orlando, Fla.) Fla.), 2019-08, Vol.197, p.120-132
• Main Authors: Schultz, Johannes, Bülthoff, Heinrich H.
• Format: Article
• Language: English
• Subjects: Adult; Animacy perception; Attention - physiology; Brain; Brain Mapping; Cognition; Cues; Experiments; Eye movements; Female; fMRI; Humans; Intraparietal sulcus; Magnetic Resonance Imaging; Male; Motion detection; Motion Perception - physiology; Neuroimaging; Parietal Lobe - physiology; Photic Stimulation; Psychophysics; Social interactions; Visual field; Visual motion; Visual perception; Visual stimuli; Young Adult
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2019.04.058

Distinguishing animate from inanimate objects is fundamental for social perception in humans and animals. Visual motion cues indicative of self-propelled object motion are useful for animacy perception: they can be detected over a wide expanse of visual field, at distance and in low visibility conditions, can attract attention and provide clues about object behaviour. However, the neural correlates of animacy perception evoked exclusively by visual motion cues, i.e. not relying on form, background or visual context, are unclear. We aimed to address this question in four psychophysical experiments in humans, two of which performed during neuroimaging. The stimulus was a single dot with constant form that moved on a blank background and evoked controlled degrees of perceived animacy through parametric variations of self-propelled motion cues. BOLD signals reflecting perceived animacy in a graded manner irrespective of eye movements were found in one intraparietal region. Additional whole-brain and region-of-interest analyses revealed no comparable effects in brain regions associated with social processing or other areas. Our study shows that animacy perception evoked solely by visual motion cues, a basic perceptual process in social cognition, engages brain regions not primarily associated with social cognition. •Self-propelled motion cues evoked graded percepts of animacy from motion only.•Occipital regions were sensitive to the amount of cues evoking animacy.•Only one cluster in right IPS was sensitive to percept changes.•IPS response may reflect accumulation of evidence about animacy.•No effects of perceived animacy were found in ventral or lateral temporal regions.