Decay and interference effects in visuospatial short-term memory

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Recognising the ageing face: the role of age in face processing

The effects of age-induced changes on face recognition were investigated as a means of exploring the role of age in the encoding of new facial memories. The ability of participants to recognise each of six previously learnt faces was tested with versions which were either identical to the learnt faces, the same age (but different in pose and expression), or younger or older in age. Participants were able to cope well with facial changes induced by ageing: their performance with older, but not younger, versions was comparable to that with faces which differed only in pose and expression. Since the large majority of different age versions were recognised successfully, it can be concluded that the process of recognition does not require an exact match in age characteristics between the stored representation of a face and the face currently in view. As the age-related changes explored here were those that occur during the period of growth, this in turn implies that the underlying structural physical properties of the face are (in addition to pose and facial expression) invariant to a certain extent

Factors influencing the accuracy of age-estimates of unfamiliar faces

Factors affecting the accuracy with which adults could assess the age of unfamiliar male faces aged between 5 and 70 years were examined. In the first experiment twenty-five 'young' adult subjects, aged 16-25, and twenty-five 'old' adults, aged 51-60, were used. Each subject saw five versions of three different faces: these consisted of an original version of each face and four manipulated versions of it. The manipulations consisted of mirror reversal, pseudo-cardioidal strain, thresholding, and elimination of all but the internal features of the face. The second experiment was similar except that a between-subjects design was used: each subject saw three faces for each age category of target face, but was exposed to only a single type of manipulation (plus a set of 'original' faces which were identical for all groups, so that the comparability of the different groups in age estimation could be checked). Results from both experiments were similar. Age estimates for unmanipulated 'original' faces were highly accurate, although subjects were most accurate with target faces that were within their own age range. Results for the manipulated faces implied that the importance of cardioidal strain as a necessary and sufficient cue to age may have been overestimated in previous reports: subjects' age estimates were accurate when cardioidal strain was absent from the stimulus, and poor when cardioidal strain was the only cue available

Understanding face identification through within-person variability in appearance: Introduction to a virtual special issue

In the effort to determine the cognitive processes underlying the identification of faces, the dissimilarities between images of different people have long been studied. In contrast, the inherent variability between different images of the same face has either been treated as a nuisance variable that should be eliminated from psychological experiments or it has not been considered at all. Over the past decade, research efforts have increased substantially to demonstrate that this within-person variation is meaningful and can give insight into various processes of face identification, such as identity matching, face learning, and familiar face recognition. In this virtual special issue of the Quarterly Journal of Experimental Psychology, we explain the importance of within-person variability for face identification and bring together recent relevant articles published in the journal

Configurational factors in the perception of unfamiliar faces

Young et al (1987) have demonstrated that the juxtaposition of top and bottom halves of different faces produces a powerful impression of a novel face. It is difficult to isolate perceptually either half of the 'new' face. Inversion of the stimulus, however, makes this task easier. Upright chimeric faces appear to evoke strong and automatic configurational processing mechanisms which interfere with selective piecemeal processing. In this paper three experiments are described in which a matching paradigm was used to show that Young et al's findings apply to unfamiliar as well as to familiar faces. The results highlight the way in which minor procedural differences may alter the way in which subjects perform face-recognition tasks

Multi-region relaxed magnetohydrodynamics with anisotropy and flow

We present an extension of the multi-region relaxed magnetohydrodynamics (MRxMHD) equilibrium model that includes pressure anisotropy and general plasma flows. This anisotropic extension to our previous isotropic model is motivated by Sun and Finn's model of relaxed anisotropic magnetohydrodynamic equilibria. We prove that as the number of plasma regions becomes infinite, our anisotropic extension of MRxMHD reduces to anisotropic ideal MHD with flow. The continuously nested flux surface limit of our MRxMHD model is the first variational principle for anisotropic plasma equilibria with general flow fields.Comment: 11 pages, 2 figures. arXiv admin note: text overlap with arXiv:1401.307

Evidence for holistic processing of faces viewed as photographic negatives

Inversion and photographic negation both impair face recognition. Inversion seems to disrupt processing of the spatial relationship between facial features ('relational' processing) which normally occurs with upright faces and which facilitates their recognition. It remains unclear why negation affects recognition. To find out if negation impairs relational processing, we investigated whether negative faces are subject to the 'chimeric-face effect'. Recognition of the top half of a composite face (constructed from top and bottom halves of different faces) is difficult when the face is upright, but not when it is inverted. To perform this task successfully, the bottom half of the face has to be disregarded, but the relational processing which normally occurs with upright faces makes this difficult. Inversion reduces relational processing and thus facilitates performance on this particular task. In our experiments, subjects saw pairs of chimeric faces and had to decide whether or not the top halves were identical. On half the trials the two chimeras had identical tops; on the remaining trials the top halves were different. (The bottom halves were always different.) All permutations of orientation (upright or inverted) and luminance (normal or negative) were used. In experiment 1, each pair of 'identical' top halves were the same in all respects. Experiment 2 used differently oriented views of the same person, to preclude matches being based on incidental features of the images rather than the faces displayed within them. In both experiments, similar chimeric-face effects were obtained with both positive and negative faces, implying that negative faces evoke some form of relational processing. It is argued that there may be more than one kind of relational processing involved in face recognition: the 'chimeric-face effect' may reflect an initial 'holistic' processing which binds facial features into a 'Gestalt', rather than being a demonstration of the configurational processing involved in individual recognition

Understanding face detection with visual arrays and real-world scenes

Face detection has been studied by presenting faces in blank displays, object arrays, and real-world scenes. This study investigated whether these display contexts differ in what they can reveal about detection, by comparing frontal-view faces with those shown in profile (Experiment 1), rotated by 90º (Experiment 2), or turned upside-down (Experiment 3). In blank displays, performance for all face conditions was equivalent, whereas upright frontal faces showed a consistent detection advantage in arrays and scenes. Experiment 4 examined which facial characteristics drive this detection advantage by rotating either the internal or external facial features by 90º while the other features remained upright. Faces with rotated internal features were detected as efficiently as their intact frontal counterparts, whereas detection was impaired when external features were rotated. Finally, Experiment 5 applied Voronoi transformations to scenes to confirm that complexity of stimulus displays modulates the detection advantage for upright faces. These experiments demonstrate that context influences what can be learned about the face detection process. In complex visual arrays and natural scenes, detection proceeds more effectively when external facial features are preserved in an upright orientation. These findings are consistent with a cognitive detection template that focuses on general face-shape information

Effects of geometric distortions on face recognition performance.

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