Leslie Zebrowitz - US grants

social psychology; face expression;

Considerable research demonstrates that people have a strong tendency to use facial appearance when forming first impressions of others' psychological traits, and that these impressions show considerable consensus across perceivers. The aim of the proposed research is to explain consensual first impressions of faces. The explanation to be tested is that social attributes revealed by the facial qualities that mark babies, fitness, or emotion are overgeneralized to people whose facial structure resembles that of babies, a particular level of fitness, or a particular emotional state. Research investigating relationships between facial qualities and trait impressions has provided indirect support for the overgeneralization hypothesis. However, the assumption that these impressions actually happen because of the overgeneralization of reactions to faces has not been tested. Connectionist modeling will be used to test the overgeneralization hypothesis. This technique may reveal whether the physical similarity between two faces is sufficient to account for similar impressions of them independent of similarities in the social or semantic implications of the faces. A series of experiments will provide facial metrics as input to standard back-propagation neural networks. Additional experiments will be conducted to determine whether human perceivers' impressions of the faces can be predicted from the responses of the networks. The proposed experiments will test the overgeneralization explanations for consensual first impressions of faces, and they will help identify the qualities that distinguish among faces that vary in emotional expression, genetic fitness, and maturity. The research will contribute to a better understanding of how people form impressions of one another, and ultimately how such impressions influence social interaction and interpersonal relationships.

DESCRIPTION (provided by applicant): Considerable research demonstrates a strong tendency to use facial appearance when forming first impressions. Moreover, these impressions show remarkable consensus, yielding significant social consequences. The long-range objective of the proposed research is to explain consensual first impressions of faces and to develop methods for ameliorating their negative social consequences. The working hypothesis is that the psychological qualities that are accurately revealed by the functionally significant facial qualities that mark babies, unfitness, emotion, or identity are overgeneralized to people whose facial structure resembles that of babies, a particular level of fitness, a particular emotion, or a particular identity. The research has three specific aims. One is to use connectionist modeling to test the facial identity overgeneralization hypothesis that the tendency for responses to strangers to vary with their facial resemblance to known individuals contributes to racial prejudice and stereotyping. The connectionist modeling experiments seek to demonstrate that the physical similarity between two faces can in and of itself account for similar impressions of them quite apart from similarities in the social categories of the faces. The second aim is to test whether generalized mere exposure effects can be used to reduce race and age prejudice and stereotyping, as predicted by the facial identity overgeneralization hypothesis. The mere exposure experiments seek to demonstrate that increasing the familiarity of an out-group facial prototype will decrease negative reactions to out-group members. The third aim is to use functional Magnetic Resonance Imaging (fMRI) to investigate neural activation patterns in response to faces that are predicted from each of the three overgeneralization hypotheses. The fMRI experiments seek to determine whether categories of faces that are differentiated by human judges' ratings and by the activation they elicit in connectionist modeling experiments also elicit distinct patterns of neural activation, thereby demonstrating a neural substrate for the overgeneralization effects. By focusing on the structured facial information that influences prejudice and stereotypes, the proposed research brings a novel theoretical perspective to the field of social cognition, demonstrating that the intrinsic properties of faces make a significant contribution to social biases that have been largely viewed as social constructions. It also suggests novel interventions for reducing prejudice.

Face perception is perhaps the most developed visual perception skill, with considerable neuroscientific evidence for the involvement of a number of brain areas. Theory and research in this discipline emphasizes a distinction between processes involved in the recognition of identity and the recognition of emotional expressions. Face perception also plays a critical role in social interactions, and considerable research in social psychology has identified consensual, evaluative trait judgments based on facial structure. The babyface overgeneralization hypothesis has been proposed to account for certain consensual trait impressions, and it has been supported using a variety of methods. In particular, adults with facial structures that resemble those of babies are judged to have the childlike traits of naivete, physical weakness, warmth, and submissiveness, and the extent to which an artificial neural network confuses adult faces with those of babies predicts impressions of these traits. The proposed research will test this overgeneralization hypothesis by examining human brain activation using functional magnetic resonance imaging (fMRI). Experiment 1 will identify regions and patterns of brain activation that differentiate responses to faces of babies and adults, and Experiment 2 will determine a) whether some adult faces elicit brain activation more similar to that shown to babies' faces, and b) whether trait impressions of these adult faces can be predicted from the similarity of the brain activation they produce to that produced by babies' faces. The proposed research integrates theories and research in the domains of social psychology and neuroscience to advance our understanding of face perception and facial stereotypes.

DESCRIPTION (provided by applicant): Facial appearance strongly influences first impressions, which show remarkable consensus and yield significant social consequences. The long-range objective is to explain consensual impressions among normal individuals and their absence in individuals with disorders such as autism. It is hypothesized that qualities that are accurately revealed by facial features that mark babies, unfitness, or identity are overgeneralized to people whose facial structure resembles that of babies, a particular level of fitness, or a particular identity. Four specific research aims are: 1)connectionist modeling tests the facial identity overgeneralization hypothesis (FIOH) that the tendency for responses to strangers to vary with their facial resemblance to known individuals contributes to social categorization effects; 2)functional Magnetic Resonance Imaging (fMRI) investigates brain activation patterns in response to faces that are predicted from each of the overgeneralization hypotheses; 3)generalized mere exposure paradigms investigate whether familiarization with the facial prototype of a category changes impressions of new category members, as predicted by the FIOH; 4)virtual reality methods test face overgeneralization hypotheses through behavioral responses to faces in various social contexts. Four training aims are: 1) increased knowledge of the conceptual foundations of computer modeling of neural systems and the computer software used to implement neural network simulations; 2) increased knowledge of brain structure and function and fMRI techniques; 3) learning to use virtual environments to assess the perceived behavioral affordances of different facial qualities; 4) integrating various methods to provide more sophisticated tests of the face overgeneralization hypotheses. The research and training benefit from excellent laboratory facilities, state of the art equipment, and interactions with outstanding scientists at Brandeis University and the MGH-NMR Center. Integrating social psychology, computer science, and neuroscience promises to advance the understanding of social perception. The focus on facial information offers a novel theoretical perspective, demonstrating that intrinsic properties of faces contribute to social biases that have been largely viewed as social constructions. It also provides a foundation for research that may elucidate neural bases of social deficits, as in autism, and develop intervention techniques to modify reactions to faces.

DESCRIPTION (provided by applicant): Successful aging is a crucial public health challenge. Because accurate trait impressions from faces provide a significant guide to adaptive social interactions, ameliorating any age-related declines in accuracy is integral to addressing that challenge, and this is the long range goal of the proposed research. Accurate assessments of traits like health, hostility, honesty, and competence are important for avoiding contagion and physical harm and seeking appropriate counsel across the lifespan. Yet, there is a dearth of research investigating the accuracy of older adults'(OA) impressions of these traits despite reason to expect age-related decrements. Young adults'(YA) trait impressions are influenced by overgeneralized responses to facial qualities that provide useful information about social interaction possibilities. More specifically, YA tend to generalize their adaptive responses to facial qualities that mark babies, low fitness, or emotion expressions to people whose facial structure merely resembles babies (babyface overgeneralization), low fitness (anomalous face overgeneralization) or an emotion expression (emotion face overgeneralization). Moreover, generalizing from negative facial qualities, including resemblance to an angry face or an anomalous face, fosters accurate trait impressions, whereas generalizing from positive facial qualities, such as high attractiveness or resemblance to a happy face or a baby's face does not. A separate body of research reveals that OA are worse than YA at recognizing negative emotion expressions, including anger, and less responsive than YA to other negatively valenced stimuli, whereas there is little age difference in recognition of happy expressions or response to positively valenced stimuli. The utility of negatively valenced facial cues for achieving accurate impressions coupled with evidence that OA may be less sensitive to such cues motivates the specific aims of the proposed research. Nine studies use behavioral, neural, and psychopharmacological methods to determine whether: 1) OA and YA show more agreement in trait impressions of faces that vary in positivity (medium to positively valenced cues) than those that vary in negativity (medium to negatively valenced cues);2) OA show less accurate trait impressions than YA;and whether age differences in trait impressions from faces are influenced by 3) decreased dopamine function in OA;4) greater emotion regulation in OA;5) more selective processing of personally relevant faces in OA;and 6) more visual dedifferentiation in OA. By integrating research on trait impressions from faces in YA with research on age-related changes in neural function, motivation, and information processing to achieve these specific aims, the proposed research will contribute to understanding when and why impressions change with age as well as what factors contribute to accurate trait impressions at any age. The findings will advance the fields of aging as well as social affective neuroscience, with implications for the development of interventions to reduce age-related vulnerabilities to maladaptive social interactions that can have negative physical, financial, or psychological repercussions. PUBLIC HEALTH RELEVANCE: Successful aging is a crucial public health challenge. Because accurate trait impressions from faces provide a significant guide to adaptive social interactions, understanding age-related changes in this process is integral to addressing that challenge. This research fills a void in the literature, assessing age differences as well as neural, motivational, and perceptual explanatory mechanisms, thereby advancing the fields of aging and neuroscience, with implications for interventions to reduce older adults'vulnerability to maladaptive social interactions.

DESCRIPTION (provided by applicant): Successful aging is a crucial public health challenge. Because accurate trait impressions from faces provide a significant guide to adaptive social interactions, ameliorating any age-related declines in accuracy is integral to addressing that challenge, and this is the long range goal of the proposed research. Accurate assessments of traits like health, hostility, honesty, and competence are important for avoiding contagion and physical harm and seeking appropriate counsel across the lifespan. Yet, there is a dearth of research investigating the accuracy of older adults' (OA) impressions of these traits despite reason to expect age-related decrements. Young adults' (YA) trait impressions are influenced by overgeneralized responses to facial qualities that provide useful information about social interaction possibilities. More specifically, YA tend to generalize their adaptive responses to facial qualities that mark babies, low fitness, or emotion expressions to people whose facial structure merely resembles babies (babyface overgeneralization), low fitness (anomalous face overgeneralization) or an emotion expression (emotion face overgeneralization). Moreover, generalizing from negative facial qualities, including resemblance to an angry face or an anomalous face, fosters accurate trait impressions, whereas generalizing from positive facial qualities, such as high attractiveness or resemblance to a happy face or a baby's face does not. A separate body of research reveals that OA are worse than YA at recognizing negative emotion expressions, including anger, and less responsive than YA to other negatively valenced stimuli, whereas there is little age difference in recognition of happy expressions or response to positively valenced stimuli. The utility of negatively valenced facial cues for achieving accurate impressions coupled with evidence that OA may be less sensitive to such cues motivates the specific aims of the proposed research. Nine studies use behavioral, neural, and psychopharmacological methods to determine whether: 1) OA and YA show more agreement in trait impressions of faces that vary in positivity (medium to positively valenced cues) than those that vary in negativity (medium to negatively valenced cues); 2) OA show less accurate trait impressions than YA; and whether age differences in trait impressions from faces are influenced by 3) decreased dopamine function in OA; 4) greater emotion regulation in OA; 5) more selective processing of personally relevant faces in OA; and 6) more visual dedifferentiation in OA. By integrating research on trait impressions from faces in YA with research on age-related changes in neural function, motivation, and information processing to achieve these specific aims, the proposed research will contribute to understanding when and why impressions change with age as well as what factors contribute to accurate trait impressions at any age. The findings will advance the fields of aging as well as social affective neuroscience, with implications for the development of interventions to reduce age-related vulnerabilities to maladaptive social interactions that can have negative physical, financial, or psychological repercussions.