Perception

We conducted two experiments to investigate the psychological factors affecting the attractiveness of composite faces. Feminised or juvenilised Japanese faces were created by morphing between average male and female adult faces or between average male (female) adult and boy (girl) faces. In experiment 1, we asked the participants to rank the attractiveness of these faces. The results showed moderately juvenilised faces to be highly attractive. In experiment 2, we analysed the impressions the participants had of the composite faces by the semantic-differential method and determined the factors that largely affected attractiveness. On the basis of the factor scores, we plotted the faces in factor spaces and analysed the locations of attractive faces. We found that most of the attractive juvenilised faces involved impressions corresponding to an augmentation of femininity, characterised by the factors of ‘elegance’, ‘mildness’, and ‘youthfulness’, which the attractive faces potentially had.

Several studies have shown that facial attractiveness is positively correlated with both familiarity and typicality. Here we manipulated the familiarity of typical and distinctive faces to measure the effect on attractiveness. In our first experiment, we collected ratings of attractiveness, distinctiveness, and familiarity using three different groups of participants. Our stimuli included 84 images of female faces, presented in a full-face view. We replicated the finding that attractiveness ratings negatively correlate with distinctiveness ratings. In addition, we showed that attractiveness ratings were positively correlated with familiarity ratings. In our second experiment, we demonstrated that increasing exposure to faces increases their attractiveness, although there was no differential effect of exposure on typical and distinctive faces. Our results suggest that episodic familiarity affects attractiveness ratings independently of general or structural familiarity. The implications of our findings for the ‘face-space’ model are discussed.

We report an experiment in which participants made gender judgments (male or female) to faces. There were three groups of faces: unfamiliar, familiar (celebrities), and a set which had been learned earlier by the participants during the experimental session. The principal purpose of this study was to establish an indirect measure of assessing whether faces have become familiar through learning that does not require overt recognition. Bruce and Young's (1986 British Journal of Psychology 77 305–327) model of face recognition suggests face-processing tasks are independent of one another and so familiarity should have no impact on the time taken to perform gender decisions. However, recent studies have suggested that some face processes are not completely independent. A gender judgment is a simple task which would be useful in face-learning experiments. We examined whether exposure to previously novel faces facilitates a later gender decision to those faces. During a learning stage, participants viewed a set of unfamiliar faces. At test, participants were able to assign gender faster to previously familiar (famous) faces and learned faces than they were to unfamiliar faces. Therefore familiarity can influence the speed at which gender is analysed. We explain our findings with reference to the Burton et al (1990 British Journal of Psychology 81 361–380) interactive activation and competition (IAC) model of face recognition and discuss how the gender judgment might be employed as a means of tracking the acquisition of familiarity in face-learning studies.

Is the extraction of a visually derived semantic code from faces (ethnicity) affected by face identity (familiarity) or not? The traditional view considers that this operation is made independently of face identity, and in parallel with the recognition of identity. However, some recent studies cast doubt on this parallel thesis regarding other visually derived semantic codes, namely: facial expression, facial speech, apparent age, and gender. Twenty-eight Caucasian participants were enrolled in an ‘ethnic-decision’ task on morphed faces made of an Asiatic source face and a Caucasian source face, in the proportion of 70%–30%. Half of the original faces were previously made familiar by a learning procedure (associating the face, surname, occupation, and city of residence of the person displayed), while the remaining half were unfamiliar. The results showed clearly that ethnic decision was affected by face familiarity. This adds support to the thesis according to which the identification of identity and the extraction of visually derived semantic codes are not made independently from each other and that the ‘parallel-route’ hypothesis becomes weakly supported.

Elements of a contour are often easier to detect when they possess collinearity, with their local orientations matching the global orientation of the contour. We recently reported attentional modulation of such lateral interactions between a central near-threshold target Gabor patch and flanking high-contrast patches (Freeman et al, 2001 Nature Neuroscience 4 1032–1036). Here, we examined whether such attentional effects reflect specific modulation of mechanisms sensitive to collinear configurations, or instead more general modulation of sensitivity to either the global or local orientation-components of the stimulus. Thresholds for detecting a central Gabor target were measured, while observers also judged the Vernier alignment between one pair of flankers and ignored a second flanker pair (when present). Target contrast-thresholds were facilitated only when attending collinear flankers. There was no facilitation when attending flankers that shared only local orientation with the target, or flankers that fell on a global axis aligned with target orientation but having orthogonal local orientation. Ignored collinear flankers had no effect on target thresholds. These results demonstrate strong and specific attentional modulation of contour-integration mechanisms in early vision sensitive to collinear configurations.

We examined the effects of previewing one aspect of a search display, in order to determine what subset of display information is most useful as a prelude to a search task. Observers were asked to indicate the presence or absence of a known target, in a conjunction search where the target was defined by the combination of colour and orientation (a yellow horizontal line presented among yellow vertical and pink horizontal distractors). In the colour preview condition of experiment 1, observers were first shown a 1 s preview of the locations and colours of the search items before the actual search set was presented. That is, search items first appeared as yellow and pink squares for 1 s, which each then turned into yellow and pink oriented lines (in the same locations) which comprised the display to be searched. In the orientation preview condition, observers were first shown a 1 s preview of the locations and orientations of the search items before the actual search display was presented. These two conditions were compared to a control condition consisting of standard conjunction search without any preview display. There was no effect of colour preview; there was a marginal effect of orientation preview, but in the opposite direction from what was expected—reaction time increased for orientation preview searches. In experiment 2 these previews were compared to two spatial cueing conditions; in this experiment the colour preview did provide a small amount of help. Finally, in experiment 3 both previews were presented in succession, and increased facilitation was found, in particular when the colour preview preceded the orientation preview. These findings are discussed in relation to the literature, in particular the Guided Search model (Wolfe et al 1989 Journal of Experimental Psychology: Human Perception and Performance 15 419–433; Wolfe 1994 Psychonomic Bulletin & Review 1 202–238).

Theories of object recognition differ to the extent that they consider object representations as being mediated only by the shape of the object, or shape and surface details, if surface details are part of the representation. In particular, it has been suggested that color information may be helpful at recognizing objects only in very special cases, but not during basic-level object recognition in good viewing conditions. In this study, we collected normative data (naming agreement, familiarity, complexity, and imagery judgments) for Snodgrass and Vanderwart's object database of 260 black-and-white line drawings, and then compared the data to exactly the same shapes but with added gray-level texture and surface details (set 2), and color (set 3). Naming latencies were also recorded. Whereas the addition of texture and shading without color only slightly improved naming agreement scores for the objects, the addition of color information unambiguously improved naming accuracy and speeded correct response times. As shown in previous studies, the advantage provided by color was larger for objects with a diagnostic color, and structurally similar shapes, such as fruits and vegetables, but was also observed for man-made objects with and without a single diagnostic color. These observations show that basic-level ‘everyday’ object recognition in normal conditions is facilitated by the presence of color information, and support a ‘shape + surface’ model of object recognition, for which color is an integral part of the object representation. In addition, the new stimuli (sets 2 and 3) and the corresponding normative data provide valuable materials for a wide range of experimental and clinical studies of object recognition.

The failure of shape constancy from stereoscopic information is widely reported in the literature. In this study we investigate how shape constancy is influenced by the size of the object and by the shape of the object's surface. Participants performed a shape-judgment task on objects of five sizes with three different surface shapes. The shapes used were: a frontoparallel rectangle, a triangular ridge surface, and a cylindrical surface, all of which contained the same maximum depth information, but different variations in depth across the surface. The results showed that, generally, small objects appear stretched and large objects appear squashed along the depth dimension. We also found a larger variance in shape judgments for rectangular stimuli than for cylindrical and ridge-shaped stimuli, suggesting that, when performing shape judgments with cylindrical and ridge-shaped stimuli, observers rely on a higher-order shape representation.

When a global moving pattern is superimposed on high-contrast stationary or slowly moving stimuli, the latter occasionally disappear for periods of several seconds (motion-induced blindness, MIB). Here, an adaptation paradigm was used to determine if orientation-selective adaptation still occurs for the stimulus that is no longer visible. Two slowly drifting high-contrast Gabor patches were presented to observers. As soon as both patches disappeared, one was eliminated from the screen. After 2 s, two low-contrast Gabor patches were presented as tests at the same locations and observers were asked to report their orientations. The observers' performance was significantly higher when the orientation of the low-contrast test patch was orthogonal to the orientation of the high-contrast adapting patch (p < 0.0001) for the location where the patch was present during MIB, even though it was perceptually invisible. The observers' performance was not significantly different at the adjacent control location where the stimulus was absent during the MIB. Although no stimulus was visible at either location, orientation-selective adaptation was preserved only for the location at which the patch remained present. Since orientation information is processed in low-level visual areas such as the primary visual cortex (V1), we conclude that MIB originates in an area higher than V1.