Face adaptation: behavioural and electrophysiological studies on the perception of eye gaze and gender

Whereas the investigation of perceptual aftereffects has a very long tradition in studies on low-level vision, the report and analysis of face-related high-level aftereffects is a very recent line of research. Webster et al. (2004, Nature) first showed a visual aftereffect on the perception of face gender by demonstrating that adaptation to male faces biased the subsequent classification of androgynous faces towards female gender. Similar adaptation effects have also been observed for one of the most important social signals: human eye gaze. Jenkins et al. (2006, Psychological Science) found that adaptation to gaze in one direction virtually eliminated participants’ ability to perceive smaller gaze deviations in the same direction. The present thesis further examined these high-level face aftereffects by determining the temporal characteristics of gaze adaptation and by analysing the neural correlates of eye gaze and gender adaptation. A behavioural study on the temporal decay of gaze adaptation effects shed further light on their basic characteristics: not only was the aftereffect surprisingly long-lasting, but its exponential decay revealed remarkable similarity with the time course of low-level adaptation effects. Further, in a series of event-related potential (ERP) studies it was found that the N170 was only marginally affected by both eye gaze and gender adaptation, whereas pronounced effects of both kinds of adaptation emerged in the P3 component with smaller amplitudes in response to test stimuli similar to the adaptation condition. Finally, gaze adaptation was found to affect ERPs in an earlier time interval ~250-350 ms which appeared to be sensitive to the discrimination between direct vs. averted gaze even when this was only an illusionary percept induced by adaptation. Together, these studies extend previous knowledge of the temporal parameters and the neural correlates of high-level face adaptation

Combined effects of inversion and feature removal on N170 responses elicited by faces and car fronts

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.bandc.2013.01.002. © 2013. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The face-sensitive N170 is typically enhanced for inverted compared to upright faces. Itier, Alain, Sedore, and McIntosh (2007) recently suggested that this N170 inversion effect is mainly driven by the eye region which becomes salient when the face configuration is disrupted. Here we tested whether similar effects could be observed with non-face objects that are structurally similar to faces in terms of possessing a homogeneous within-class first-order feature configuration. We presented upright and inverted pictures of intact car fronts, car fronts without lights, and isolated lights, in addition to analogous face conditions. Upright cars elicited substantial N170 responses of similar amplitude to those evoked by upright faces. In strong contrast to face conditions however, the car-elicited N170 was mainly driven by the global shape rather than the presence or absence of lights, and was dramatically reduced for isolated lights. Overall, our data confirm a differential influence of the eye region in upright and inverted faces. Results for car fronts do not suggest similar interactive encoding of eye-like features and configuration for non-face objects, even when these objects possess a similar feature configuration as faces

Past visual experiences weigh in on body size estimation

Abstract Body size is a salient marker of physical health, with extremes implicated in various mental and physical health issues. It is therefore important to understand the mechanisms of perception of body size of self and others. We report a novel technique we term the bodyline, based on the numberline technique in numerosity studies. One hundred and three young women judged the size of sequentially presented female body images by positioning a marker on a line, delineated with images of extreme sizes. Participants performed this task easily and well, with average standard deviations less than 6% of the total scale. Critically, judgments of size were biased towards the previously viewed body, demonstrating that serial dependencies occur in the judgment of body size. The magnitude of serial dependence was well predicted by a simple Kalman-filter ideal-observer model, suggesting that serial dependence occurs in an optimal, adaptive way to improve performance in size judgments

Impressions of sexual unfaithfulness and their accuracy show a degree of universality

his research was supported by the Australian Research Council (ARC) Centre of Excellence in Cognition and its Disorders (CE110001021) and an ARC Discovery Outstanding Researcher Award to GR (DP130102300), an ARC Discovery project to GR and CS (DP170104602) and an ARC Professorial Fellowship to LS (DP110104594). The funders had no influence on the research.Peer reviewedPublisher PD

How well do computer-generated faces tap face expertise?

The use of computer-generated (CG) stimuli in face processing research is proliferating due to the ease with which faces can be generated, standardised and manipulated. However there has been surprisingly little research into whether CG faces are processed in the same way as photographs of real faces. The present study assessed how well CG faces tap face identity expertise by investigating whether two indicators of face expertise are reduced for CG faces when compared to face photographs. These indicators were accuracy for identification of own-race faces and the other-race effect (ORE)-the well-established finding that own-race faces are recognised more accurately than other-race faces. In Experiment 1 Caucasian and Asian participants completed a recognition memory task for own- and other-race real and CG faces. Overall accuracy for own-race faces was dramatically reduced for CG compared to real faces and the ORE was significantly and substantially attenuated for CG faces. Experiment 2 investigated perceptual discrimination for own- and other-race real and CG faces with Caucasian and Asian participants. Here again, accuracy for own-race faces was significantly reduced for CG compared to real faces. However the ORE was not affected by format. Together these results signal that CG faces of the type tested here do not fully tap face expertise. Technological advancement may, in the future, produce CG faces that are equivalent to real photographs. Until then caution is advised when interpreting results obtained using CG faces

On the other side of the fence: effects of social categorization and spatial grouping on memory and attention for own-race and other-race faces.

The term "own-race bias" refers to the phenomenon that humans are typically better at recognizing faces from their own than a different race. The perceptual expertise account assumes that our face perception system has adapted to the faces we are typically exposed to, equipping it poorly for the processing of other-race faces. Sociocognitive theories assume that other-race faces are initially categorized as out-group, decreasing motivation to individuate them. Supporting sociocognitive accounts, a recent study has reported improved recognition for other-race faces when these were categorized as belonging to the participants' in-group on a second social dimension, i.e., their university affiliation. Faces were studied in groups, containing both own-race and other-race faces, half of each labeled as in-group and out-group, respectively. When study faces were spatially grouped by race, participants showed a clear own-race bias. When faces were grouped by university affiliation, recognition of other-race faces from the social in-group was indistinguishable from own-race face recognition. The present study aimed at extending this singular finding to other races of faces and participants. Forty Asian and 40 European Australian participants studied Asian and European faces for a recognition test. Faces were presented in groups, containing an equal number of own-university and other-university Asian and European faces. Between participants, faces were grouped either according to race or university affiliation. Eye tracking was used to study the distribution of spatial attention to individual faces in the display. The race of the study faces significantly affected participants' memory, with better recognition of own-race than other-race faces. However, memory was unaffected by the university affiliation of the faces and by the criterion for their spatial grouping on the display. Eye tracking revealed strong looking biases towards both own-race and own-university faces. Results are discussed in light of the theoretical accounts of the own-race bias

Adaptation Effects to Attractiveness of Face Photographs and Art Portraits are Domain-Specific

We studied the neural coding of facial attractiveness by investigating effects of adaptation to attractive and unattractive human faces on the perceived attractiveness of veridical human face pictures (Experiment 1) and art portraits (Experiment 2). Experiment 1 revealed a clear pattern of contrastive aftereffects. Relative to a pre-adaptation baseline, the perceived attractiveness of faces was increased after adaptation to unattractive faces, and was decreased after adaptation to attractive faces. Experiment 2 revealed similar aftereffects when art portraits rather than face photographs were used as adaptors and test stimuli, suggesting that effects of adaptation to attractiveness are not restricted to facial photographs. Additionally, we found similar aftereffects in art portraits for beauty, another aesthetic feature that, unlike attractiveness, relates to the properties of the image (rather than to the face displayed). Importantly, Experiment 3 showed that aftereffects were abolished when adaptors were art portraits and face photographs were test stimuli. These results suggest that adaptation to facial attractiveness elicits aftereffects in the perception of subsequently presented faces, for both face photographs and art portraits, and that these effects do not cross image domains

On the Other Side of the Fence: Effects of Social Categorization and Spatial Grouping on Memory and Attention for Own-Race and Other-Race Faces - Figure 6

<p>A. Mean proportion of viewing time spent on own-race and other-race faces for Asian and European participants in the university grouping condition. B. Mean proportion of viewing time spent on own-race and other-race faces for Asian and European participants in the race grouping condition. Error bars indicate standard errors of the mean.</p

Mean d′ for own-race and other-race faces. Error bars show standard errors of the mean.

<p>Mean d′ for own-race and other-race faces. Error bars show standard errors of the mean.</p