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Face perception: ERP correlates of Rapid Adaptation, Category-selectivity, Recognition, and Individual Differences.

Sunday, October 02nd,   2011 [09:30 - 11:10]

SY_25. Face perception: ERP correlates of Rapid Adaptation, Category-selectivity, Recognition, and Individual Differences

Schweinberger, S. R. 1, 2

1 DFG Research Unit Person Perception
2 Department of General Psychology, Friedrich Schiller University, Jena, Germany

The efficient analysis and representation of person-related information from faces is one of the most important challenges for human social perception. This symposium discusses a number of current and controversial issues in research on face perception. Martin Eimer will present current evidence for a systematic pattern of selective neural adaptation effects, suggesting that several dissociable processes are involved in early stages of face processing as reflected in the N170 ERP. Guillaume Thierry will then discuss research on early category-selective ERPs that compares the P1 and N170 components with respect to their face-selectivity and response to experimental variations including inter-stimulus variability and stimulus integrity. Stefan R. Schweinberger presents evidence for multiple face-sensitive ERP responses including occipitotemporal N170, P2, N250r components as well as a centroparietal N400, and argues that further progress in this field requires consideration of the variety of ERP responses that relate to different functional components of face perception. Finally, Werner Sommer reports about research to establish face cognition abilities as specific elements of social intelligence from an individual differences perspective, age-related changes, and electrophysiological correlates of these abilities. As a whole, these presentations sketch future directions in face perception research that will further elucidate how structural facial information, as well as cues to social information such as age, gender, identity and others are represented and processed in the human brain.



SY_25.1 - Rapid neural adaptation: A new tool for the study of face perception

Eimer, M.

Department of Psychology, Birkbeck College, University of London, UK

I will present results from a series of event-related brain potential (ERP) studies that used rapid neural adaptation (or repetition suppression) procedures to study component processes of face perception, and how these processes are reflected by the face-sensitive N170 component. Face and non-face adaptor stimuli (S1) and test face stimuli (S2) were presented for 200 ms, and were separated by a very brief (200 ms) interstimulus interval. The pattern of N170 adaptation effects measured in response to test faces that were preceded by different types of adaptor stimuli provided new insights into the organisation of face processing, and into the category-selectivity of brain activity that is reflected by N170 responses. Results observed with naturalistic, schematic, and Mooney face adaptors suggest that several dissociable processes are involved in early stages of face processing, including the generic analysis of individual face parts, in particular the eyes, as well as configural and holistic face processing. The systematic pattern of N170 adaptation effects observed across experiments demonstrates the potential of the rapid adaptation technique as a tool to dissociate component processes of face perception, and also underlines the fact that the N170 component is a direct electrophysiological index of neural mechanisms that implement human face processing.

SY_25.2 - P1 and N170 face-to-face: When does the human brain distinguish between visual object categories?

Thierry, G. 1 , Dering, B. 1 , Martin, C. 2 & Pegna, A. 3

1 School of Psychology, Bangor University, Bangor, UK
2 Department of Technology, Universitat de Pompeu Fabra, Barcelona, Spain
3 Neurology Department, Geneva University Hospital, Geneva, Switzerland

The human face is the most studied object category in visual neuroscience. In a quest for markers of face processing, event-related potential (ERP) studies have debated whether two peaks of activity -P1 and N170- are category-selective. I will briefly present datasets from six studies involving two-by-two experimental designs showing that P1 mean amplitude significantly distinguishes faces from cars -an object category often compared to faces- independently of modulations elicited by inter-stimulus variability, external feature cropping, and inter-category morphing: (1) By manipulating randomly generated inter-stimulus variability (high vs. low) and object category (cars, faces, butterflies), we show that P1 is weakly sensitive to variability but robustly category-selective, whilst the N170 unexpectedly shows the reverse pattern of response (Thierry et al. 2007; Dering et al., 2009). (2) By manipulating stimulus integrity via deletion of peripheral features of faces (hair, ears, and neck) and cars (rooftop, wing mirrors, and wheels), we show that cropping artificially increases N170 but not P1 amplitude and leaves P1 category-sensitivity intact. (3) By morphing full-front views of faces and cars to different extents, we show that P1 category-selectivity resists 30% contamination of one category by visual information from the other category, whilst the N170 fails to respond to the amount of face information embedded in the stimulus. In sum, we show that the N170 peak of visual event-related brain potentials is highly sensitive to factors other than object category, whereas P1 amplitude is modulated in a face-selective fashion as early as 100 ms after picture onset

SY_25.3 - Neurophysiological correlates of face recognition

Schweinberger, S. R. 1, 2

1 DFG Research Unit Person Perception
2 Department of General Psychology and Cognitive Neuroscience, Friedrich Schiller University, Jena, Germany

I will present part of a 20-year research programme in which my colleagues and I have used cognitive (e.g., Bruce & Young, 1986) and computational (e.g., Burton et al., 1990) models as frameworks for the study of neurophysiological correlates of face recognition. Here, face recognition has been conceived as a complex facility that requires the orchestrated activity of multiple neurocognitive subroutines (cf. the contributions in Schweinberger, S.R. & Burton, A.M., Eds., 2011. Person Perception 25 years after Bruce and Young (1986). Special Issue, British Journal of Psychology, 102(4), 2011). I will argue that a substantial part of electrophysiological research has seen a strong focus on the N170, at the expense of other face-sensitive ERP components including those that were shown to relate more specifically to individual face recognition. I will briefly discuss evidence for multiple face-sensitive components suggesting that (a) the N170 is related to face detection and structural encoding, but not recognition, (b) the occipitotemporal P2 is sensitive to second-order spatial configuration, and possibly indexes processes related to unfamiliar face learning and population expertise, (c) the posterior temporal N250r is highly sensitive to face familiarity and can index individual face recognition, and (d) a centroparietal N400 systematically relates to domain-independent access of semantic information about people. I will argue that because other aspects of face perception (e.g., perception of gender, age, eye gaze, emotional expression etc.) also depend on multiple neurocognitive subroutines, further progress in electrophysiological research necessitates appreciating the variety of ERP components that relate to different functional components of face perception.

SY_25.4 - Individual Differences in Face Cognition: Psychometrics, Ageing, and Neuronal Correlates

Sommer, W. 1 , Herzmann, G. 2 , Hildebrandt, A. 1 & Wilhelm, O. 3

1 Department of Psychology, Humboldt-University at Berlin, Germany
2 Department of Psychology and Neuroscience, University of Colorado at Boulder, USA
3 Department of Psychology and Educational Science, Ulm University, Ulm, Germany

Individual differences in face cognition, an element of social intelligence, were investigated in three psychometric studies with more than 800 participants. Structural equation modeling of an extensive test battery shows that face cognition can be subdivided into distinct abilities, the accuracy of face perception, the accuracy of face memory and the speed of face cognition. The structure of face cognition remained invariant and its relation with established ability constructs was robust across the adult age range from 18 to 82 years, demonstrating its robust specificity from an individual differences perspective. Expectedly, there were substantial age related performance decrements of up to .5 SD per decade for the speed of face cognition. In a subsample of 85 young adults, we studied neuronal correlates of individual differences in face cognition with event-related brain potentials. For the N170 component, held to be an index of the structural analysis of faces, only moderate evidence was obtained for a relationship of its latency with face cognition accuracy. Stronger relationships, however, were found for the amplitudes of the memory-related Early Repetition Effect/N250r and Late Repetition Effect/N400 components with both face cognition speed and accuracy.

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