Adaptation modulates the electrophysiological substrates of perceived facial distortion: Support for opponent coding

• Published in: Neuropsychologia Vol. 48; no. 13; pp. 3743 - 3756
• Main Authors: Burkhardt, Alex, Blaha, Leslie M., Jurs, Bethany Schneider, Rhodes, Gillian, Jeffery, Linda, Wyatte, Dean, DeLong, Jordan, Busey, Tom
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.11.2010; Elsevier
• Subjects: Adaptation; Adaptation, Physiological - physiology; Adolescent; Adult; Aftereffects; Behavioral psychophysiology; Biological and medical sciences; Brain Mapping; Cerebral Cortex - physiology; Electroencephalography; Electrophysiology; Event related potential; Evoked Potentials - physiology; Face; Face processing; Female; Fundamental and applied biological sciences. Psychology; Humans; Male; Pattern Recognition, Visual - physiology; Perception; Perceptual Distortion - physiology; Photic Stimulation; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Vision; Aftereffects; Face processing; Event related potential; Adaptation; After effect; Human; Perceptual adaptation; Central nervous system; Electrophysiology; Distortion; Cognition; Encephalon; Coding; Vision; Information processing; Perception; Face; Event evoked potential
• ISSN: 0028-3932; 1873-3514
• DOI: 10.1016/j.neuropsychologia.2010.08.016

▶ P250 ERP peak amplitude is modulated by both expansion and compression face distortions. ▶ Faces perceived as more normal have larger P250 peak amplitudes. ▶ P250 peak amplitude is the electrophysiological correlate of figural face adaptation aftereffects. In two experiments we determined the electrophysiological substrates of figural aftereffects in face adaptation using compressed and expanded faces. In Experiment 1, subjects viewed a series of compressed and expanded faces. Results demonstrated that distortion systematically modulated the peak amplitude of the P250 event-related potential (ERP) component. As the amount of perceived distortion in a face increased, the peak amplitude of the P250 component decreased, regardless of whether the physical distortion was compressive or expansive. This provided an ERP metric of the degree of perceived distortion. In Experiment 2, we examined the effects of adaptation on the P250 amplitude by introducing an adapting stimulus that affected the subject's perception of the distorted test faces as measured through normality judgments. The set of test faces was held constant and the adapting stimulus was systematically varied across experimental days. Adapting to a compressed face made a less compressed test face appear more normal and an expanded test face more distorted as measured by normality ratings. We found that the adaptation conditions that increased the perceived distortion of the distorted test faces also decreased the amplitude of the P250. Likewise, adaptation conditions that decreased the perceived distortion of the distorted test faces also increased the amplitude of the P250. The results demonstrate that perceptual adaptation to compressed or expanded faces affected not only the behavioral normality judgments but also the electrophysiological correlates of face processing in the window of 190–260ms after stimulus onset.