Neuronal responses to face-like stimuli in the monkey pulvinar

• Published in: The European journal of neuroscience Vol. 37; no. 1; pp. 35 - 51
• Main Authors: Nguyen, Minh Nui, Hori, Etsuro, Matsumoto, Jumpei, Tran, Anh Hai, Ono, Taketoshi, Nishijo, Hisao
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01-01-2013; Blackwell
• Subjects: Anatomical correlates of behavior; Animals; Behavioral psychophysiology; Biological and medical sciences; Brain Waves; Cognition; Cortex (visual); Discrimination (Psychology); Face; face-like patterns; Female; Fundamental and applied biological sciences. Psychology; Information processing; Macaca; Male; monkey; Multidimensional scaling; Nervous system; Neurons; Neurons - classification; Neurons - physiology; Pattern Recognition, Visual; Photic Stimulation; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Pulvinar; Pulvinar - cytology; Pulvinar - physiology; Reaction Time; Retina; Retina - physiology; Social interactions; subcortical pathway; Superior Colliculi - physiology; Superior colliculus; Visual pathways; Visual stimuli; face-like patterns; Central nervous system; Monkey; Cognition; Encephalon; Vertebrata; Visual stimulus; Mammalia; Primates; subcortical pathway; Thalamus; Face; pulvinar
• ISSN: 0953-816X; 1460-9568
• DOI: 10.1111/ejn.12020

The pulvinar nuclei appear to function as the subcortical visual pathway that bypasses the striate cortex, rapidly processing coarse facial information. We investigated responses from monkey pulvinar neurons during a delayed non‐matching‐to‐sample task, in which monkeys were required to discriminate five categories of visual stimuli [photos of faces with different gaze directions, line drawings of faces, face‐like patterns (three dark blobs on a bright oval), eye‐like patterns and simple geometric patterns]. Of 401 neurons recorded, 165 neurons responded differentially to the visual stimuli. These visual responses were suppressed by scrambling the images. Although these neurons exhibited a broad response latency distribution, face‐like patterns elicited responses with the shortest latencies (approximately 50 ms). Multidimensional scaling analysis indicated that the pulvinar neurons could specifically encode face‐like patterns during the first 50‐ms period after stimulus onset and classify the stimuli into one of the five different categories during the next 50‐ms period. The amount of stimulus information conveyed by the pulvinar neurons and the number of stimulus‐differentiating neurons were consistently higher during the second 50‐ms period than during the first 50‐ms period. These results suggest that responsiveness to face‐like patterns during the first 50‐ms period might be attributed to ascending inputs from the superior colliculus or the retina, while responsiveness to the five different stimulus categories during the second 50‐ms period might be mediated by descending inputs from cortical regions. These findings provide neurophysiological evidence for pulvinar involvement in social cognition and, specifically, rapid coarse facial information processing.
Monkey pulvinar neuronal responses to five categories of visual stimuli (facial photos, line drawings of faces, face‐like patterns [three dark blobs on a bright oval], eye‐like patterns, and simple geometric patterns) were investigated. Face‐like patterns elicited stronger responses with the shortest latencies (50 ms). The findings suggest that the pulvinar nuclei function as the subcortical visual pathway that bypasses the striate cortex, rapidly processing coarse facial information.