Influence of task and input factors on hemispheric involvement in face processing.

Two experiments with 17 undergraduate students examined the respective role of the cerebral hemispheres in face perception and the nature of their contribution depending on task demands and on the spatial-frequency composition of the stimuli. 16 faces of members of the Ss' department were presented as stimuli, with men, women, and professors, and nonprofessors, being equally represented. In Exp I, high-resolution black-and-white photographs of faces were used in 3 reaction-time (RT) tasks: verbal identification, manual membership categorization, and manual male/female categorization, in a within-S design. Identification and membership categorization were significantly better performed in right-visual-field presentations, whereas the male/female categorization yielded a nonsignificant left-visual-field superiority. In Exp II, 2 versions of the same faces were used: digitized low-pass (0–2 cycles/degree of visual angle) and digitized broad-pass (0–32 cycle/degree) faces. Broad–pass faces produced the same laterality pattern as in Exp I, while low-pass faces were better processed in left-visual-field presentations for all 3 tasks. Results suggest that the 2 hemispheres play a role in face perception and that their contribution may vary as a function of the task demands and of spatial-frequency components of the incoming information. (54 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Face aftereffects indicate dissociable, but not distinct, coding of male and female faces.

It has been claimed that exposure to distorted faces of one sex induces perceptual aftereffects for test faces that are of the same sex, but not for test faces of the other sex (A. C. Little, L. M. DeBruine, & B. C. Jones, 2005). This result suggests that male and female faces have separate neural coding. Given the high degree of visual similarity between faces of different sexes, this result is surprising. The authors reinvestigated male and female face coding using a different face distortion. In Experiment 1, participants adapted to distorted faces from one sex (e.g., male contracted faces) and were tested with faces of both sexes. Aftereffects were found for both male and female faces, suggesting the existence of common coding mechanisms. In Experiments 2 and 3, participants adapted to oppositely distorted faces from both sexes (male contracted and female expanded faces). Weak opposite aftereffects were found for male and female faces, suggesting the existence of sex-selective face coding mechanisms. Taken together, these results indicate that both common and sex-selective mechanisms code male and female faces. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Will a category cue attract you? Motor output reveals dynamic competition across person construal.

People use social categories to perceive others, extracting category cues to glean membership. Growing evidence for continuous dynamics in real-time cognition suggests, contrary to prevailing social psychological accounts, that person construal may involve dynamic competition between simultaneously active representations. To test this, the authors examined social categorization in real-time by streaming the x, y coordinates of hand movements as participants categorized typical and atypical faces by sex. Though judgments of atypical targets were largely accurate, online motor output exhibited a continuous spatial attraction toward the opposite sex category, indicating dynamic competition between multiple social category alternatives. The authors offer a dynamic continuity account of social categorization and provide converging evidence across categorizations of real male and female faces (containing a typical or an atypical sex-specifying cue) and categorizations of computer-generated male and female faces (with subtly morphed sex-typical or sex-atypical features). In 3 studies, online motor output revealed continuous dynamics underlying person construal, in which multiple simultaneously and partially active category representations gradually cascade into social categorical judgments. Such evidence is challenging for discrete stage-based accounts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Typicality, familiarity and the recognition of male and female faces.

22 male and 43 female undergraduates provided judgments of typicality, familiarity, and recognition for each of 209 photographs of male and female faces. Results support the notion that the same-sex bias in recognition often found with female Ss is a function of perceived typicality: Female Ss rated female faces to be more typical than male faces, whereas male Ss showed no such bias. The same pattern of results was found for false–positive responses on a test of item recognition. The rated familiarity of the faces was not related to the Ss' recognition judgments, suggesting that the perceived context-free familiarity of faces is not the source of the effects of typicality or sex of face on the recognition of faces. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Applying Bubbles to Localize Features That Control Pigeons' Visual Discrimination Behavior.

The authors trained pigeons to discriminate images of human faces that displayed: (a) a happy or a neutral expression or (b) a man or a woman. After training the pigeons, the authors used a new procedure called Bubbles to pinpoint the features of the faces that were used to make these discriminations. Bubbles revealed that the features used to discriminate happy from neutral faces were different from those used to discriminate male from female faces. Furthermore, the features that pigeons used to make each of these discriminations overlapped those used by human observers in a companion study (F. Gosselin & P.G. Schyns, 2001). These results show that the Bubbles technique can be effectively applied to nonhuman animals to isolate the functional features of complex visual stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Discrimination among colony mates' anogenital odors by guinea pigs (Cavia porcellus).

Three experiments used an aversively motivated learning task to examine the ability of adult guinea pigs to discriminate among odors from nonspecific anogenital swabbings of colony mates. Exps I and II examined the ability of 8 male (M) and 8 female (F) Ss to discriminate among odors of colony mates controlled for age and sex. Both sexes were able to discriminate among individual Ss on the basis of odor. Since individual Ss could be discriminated, Exp III, examining detection of physiological estrus, tested the ability of 6 Ms and 6 Fs to discriminate preserved odor samples from the same F during conditions of estrus and nonestrus. Both Ms and Fs were able to discriminate between the conditions. Results are discussed with reference to the involvement of odor in the social behavior of guinea pigs. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The processing of invariant and variant face cues in the Garner Paradigm.

Faces provide a complex source of information via invariant (e.g., race, sex and age) and variant (e.g., emotional expressions) cues. At present, it is not clear whether these different cues are processed separately or whether they interact. Using the Garner Paradigm, Experiment 1 confirmed that race, sex, and age cues affected the categorization of faces according to emotional expression whereas emotional expression had no effect on the categorization of faces by sex, age, or race. Experiment 2 used inverted faces and replicated this pattern of asymmetrical interference for race and age cues, but not for sex cues for which no interference on emotional expression categorization was observed. Experiment 3 confirmed this finding with a more stringently matched set of facial stimuli. Overall, this study shows that invariant cues interfere with the processing of emotional expressions. It indicates that the processing of invariant cues, but not of emotional expressions, is obligatory and that it precedes that of emotional expressions. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Flexible tuning of similarity in exemplar-based categorization.

Flexibility in exemplar-based categorization was investigated in 3 experiments. 24 undergraduate Ss categorized schematic drawings of individuals' faces while they received information about the kinship relation between these individuals and previously observed exemplars. In Exps 1 and 2, initial training was incidental, whereas an intentional learning task was used in Exp 3. In all experiments, the kinship manipulation systematically affected categorizations. Model-based analyses showed that the effect of the kinship manipulation could be described by similarity-based exemplar models if it was assumed that Ss applied different levels of generalization as a function of the kinship instructions. Results demonstrate that categorization is a highly flexible process, and their methodological and theoretical implications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gender is a dimension of face recognition.

In an experiment, the authors investigated the impact of gender categorization on face recognition. Participants were familiarized with composite androgynous faces labeled with either a woman's first name (Mary) or a man's first name (John). The results indicated that participants more quickly eliminated faces of the opposite gender than faces of the same gender than the face they were looking for. This gender effect did not result from greater similarity between faces of the same gender. Rather, early gender categorization of a face during face recognition appears to speed up the comparison process between the perceptual input and the facial representation. Implications for face recognition models are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Parallel processing of the sex and familiarity of faces.

78 undergraduates were asked to rate photographs of faces as male or female and familiar or unfamiliar under a total of 4 conditions in 2 experiments. Results from Exp I indicate that faces whose sex was difficult to classify were no harder to judge as familiar than those whose sex was easy to classify. In Exp II this result was replicated and extended to a situation where the familiarity judgment was contingent on the sex judgment. Findings support the view that analyses of the face's sex and its identity proceed in parallel, rather than in hierarchical, order as claimed by H. Ellis (1986). (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Proactive interference in short-term retention of human faces.

Tested whether release from proactive interference occurs in short-term recognition memory following a shift in the learning of male faces to the learning of female faces, and vice versa. Ss were 52 female and 52 male college students. Proactive interference was found to increase over 4 successive study-test trials and a significant release effect was obtained on Trial 5. Female faces were more difficult to recognize than male faces after a build-up of proactive interference, suggesting that differential interference for sex attributes had occurred. No differences were found between male and female Ss in the release effect, but female Ss were superior to males on Trials 1-4. Results are discussed in terms of the influence of motivation on memory for faces as well as supporting a theory of visual short-term memory. (French summary) (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Discrimination and generalization along a simple dimension: Peak shift and rule-governed responding.

In 2 experiments, participants learned to discriminate between a pair of simply related, but very similar, colors in a 2-choice categorization task. They were then tested over a wider range of isoluminant hues. Over these test values, both experiments yielded a postdiscrimination gradient that was initially peak-shifted but became monotonic through the course of testing. In Experiment 2, the presence of this early peak shift and subsequent change in gradient form were related to participants’ inability to verbally characterize the difference between the training stimuli. This suggests a transition from generalization based on simple physical similarity to generalization based on a “verbalizable” rule, as a consequence of additional relevant information becoming available during test. An explanation appealing to both associative and strategically controlled verbal processes provides an accurate account of the results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of sex role stereotypes on personnel decisions.

Used an in-basket exercise to investigate the influence of sex role stereotypes on the personnel decisions of 95 male bank supervisors. 4 experiments (in-basket items) were conducted in which an employee's sex and other situational attributes were manipulated. Results confirm the hypothesis that male administrators tend to discriminate against female employees in personnel decisions involving promotion, development, and supervision. Discrimination against male employees was found in personnel decisions involving competing role demands stemming from family circumstances. Features of the decision-making process which heighten the influence of sex role stereotypes on personnel decisions are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceiving the sex and race of faces: the role of shape and colour

Theories of object recognition have emphasized the information conveyed by shape information, whereas theories of face recognition have emphasized properties of superficial features. In the experiments reported here we used novel technology to investigate the relative contributions of shape and superficial colour information to simple categorization decisions about the sex and 'race' of faces. The results show that both shape and colour provide useful information for these decisions; shape information was particularly useful for race decisions while colour dominated sex decisions. When both sources of information were combined, the dominant source depended on viewpoint, with angled views emphasizing the contribution of shape and the full-face view colour. The results are discussed within the context of theories of face recognition and their implications for telecommunication applications are considered.     

Sexual dimorphism in facial shapes and their discrimination in Japanese monkeys (Macaca fuscata).

The authors examined the ability of Japanese monkeys (Macaca fuscata) to discriminate between sexes based on facial features. The shape and position of facial features (facial morphology) were measured to quantify the differences between sexes. The distance between the chin and nose was longer in males than females, and the outline of the face around the upper jaw and upper face differed between sexes. Using operant conditioning, 2 monkeys succeeded in discriminating sex based on facial pictures. Furthermore, they successfully generalized the discrimination to novel pictures of faces. Tests with morphed pictures of faces revealed that the monkeys used facial morphology to discriminate between males and females. Our results suggest that Japanese monkeys have sexual dimorphism in facial shape and they can use the morphological differences to discriminate conspecific sex. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sequence effects in categorization of simple perceptual stimuli.

Categorization research typically assumes that the cognitive system has access to a (more or less noisy) representation of the absolute magnitudes of the properties of stimuli and that this information is used in reaching a categorization decision. However, research on identification of simple perceptual stimuli suggests that people have very poor representations of absolute magnitude information and that judgments about absolute magnitude are strongly influenced by preceding material. The experiments presented here investigate such sequence effects in categorization tasks. Strong sequence effects were found. Classification of a borderline stimulus was more accurate when preceded by a distant member of the opposite category than by a distant member of the same category. It is argued that this category contrast effect cannot be accounted for by extant exemplar or decision-bound models of categorization. The effect suggests the use of relative magnitude information in categorization. A memory and contrast model illustrates how relative magnitude information may be used in categorization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A New Learning Paradigm Elicits Fast Visual Discrimination in Pigeons.

The authors describe a novel multistimulus, multiple-matching learning paradigm for pigeons, which they believe not only simulates pigeons' natural foraging behavior but also more realistically shows their visual discrimination ability. A touch screen thin film transistor panel shows a stimulus configuration consisting of a 2-dimensional array of bitmap images that changes from trial to trial. The pigeon's task during each trial is to peck at images that are defined as positive by the experimenter. An experiment exploring the ability of pigeons to discriminate between achromatic male and female human faces demonstrated the effectiveness of the procedure. In contrast to 12 pigeons that show little improvement over 60 hr of go/no-go discrimination training, 14 multiple-matching pigeons mastered the problem within a few hours. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning correlations in categorization tasks using large, ill-defined categories.

The experiments revealed whether individual participants are sensitive to exemplar information in the form of within-category correlations between stimulus dimensions after training on large overlapping categories. Participants were trained in 1 of 2 categorization conditions. The sign of the correlation between dimensions differed across conditions, but the categorization rules that best separated the categories were identical. An unannounced attribute-prediction task followed categorization training. Several participants produced predictions consistent with the correct correlation between the dimensions. For other participants, the predictions reflected the correlation only within the region they had associated with the given category, even though the categories overlapped, suggesting that the decision boundary was explicitly represented in memory. Finally, for other participants, no correlational information appeared to be accessible for the prediction task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Second-order facial information processing in schizophrenia.

This study investigated the processing of second-order relational face information in schizophrenia. Twenty-eight schizophrenic patients and 28 controls were asked to say whether the space between the eyes was the same in 2 side-by-side faces. The 2 faces were derived from the same original face, but the spacing between the eyes was either the same or differed by various distances. The results showed that schizophrenic patients needed a space that was twice as great as controls to see a difference. The authors conclude that schizophrenic patients have a deficit in processing second-order relational face information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus type, level of categorization, and spatial-frequencies utilization: Implications for perceptual categorization hierarchies.

The type of visual information needed for categorizing faces and nonface objects was investigated by manipulating spatial frequency scales available in the image during a category verification task addressing basic and subordinate levels. Spatial filtering had opposite effects on faces and airplanes that were modulated by categorization level. The absence of low frequencies impaired the categorization of faces similarly at both levels, whereas the absence of high frequencies was inconsequential throughout. In contrast, basic-level categorization of airplanes was equally impaired by the absence of either low or high frequencies, whereas at the subordinate level, the absence of high frequencies had more deleterious effects. These data suggest that categorization of faces either at the basic level or by race is based primarily on their global shape but also on the configuration of details. By contrast, basic-level categorization of objects is based on their global shape, whereas category-specific diagnostic details determine the information needed for their subordinate categorization. The authors conclude that the entry point in visual recognition is flexible and determined conjointly by the stimulus category and the level of categorization, which reflects the observer’s recognition goal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)