Categorizing identity from facial motion

It has been suggested that acronyms like BBC are processed like real words. This claim has been based on improved performance with acronyms in the Reicher–Wheeler task, the letter string matching task, the visual feature integration task, and the N400 component in event-related potential (ERP) studies. Unfortunately, in all these tasks performance on acronyms resembled performance on pseudowords more than performance on words. To further assess the similarity of acronyms and words, we focused on the meaning of the acronyms and used masked priming to examine whether target words can be primed to the same extent with associatively related acronyms as with associatively related words. Such priming was possible at a stimulus onset asynchrony (SOA) of 84 ms. In addition, the priming of the acronyms did not depend on the letter case in which they were presented: The target word “books” was primed as much by isbn and iSbN as by ISBN.     

Preattentive recovery of three-dimensional orientation from line drawings

It has generally been assumed that rapid visual search is based on simple features and that spatial relations between features are irrelevant for this task. Seven experiments involving search for line drawings contradict this assumption; a major determinant of search is the presence of line junctions. Arrow- and Y-junctions were detected rapidly in isolation and when they were embedded in drawings of rectangular polyhedra. Search for T-junctions was considerably slower. Drawings containing T-junctions often gave rise to very slow search even when distinguishing arrow- or Y-junctions were present. This sensitivity to line relations suggests that preattentive processes can extract 3-dimensional orientation from line drawings. A computational model is outlined for how this may be accomplished in early human vision.     

Mental models of line drawings.

Mental models are internal representations of world structure, used to accomplish cognitive tasks. I postulate specific representations (of objects and images) and associated context (of world and view) for mental models of line drawings. I then analyze the representations and context to predict specific perceptual modes, including the relative strengths of these modes. The predicted modes are supported by a well-known example [from Rock, 1983 The Logic of Perception (Cambridge, MA: MIT Press)] where object perception changes with image orientation.     

Embodiment effects in memory for facial identity and facial expression

Research suggests that states of the body, such as postures, facial expressions, and arm movements, play central roles in social information processing. This study investigated the effects of approach/avoidance movements on memory for facial information. Faces displaying a happy or a sad expression were presented and participants were induced to perform either an approach (arm flexion) or an avoidance (arm extension) movement. States of awareness associated with memory for facial identity and memory for facial expression were then assessed with the Remember/Know/Guess paradigm. The results showed that performing avoidance movements increased Know responses for the identity, and Know/Guess responses for the expression, of valence-compatible stimuli (i.e., sad faces as compared to happy faces), whereas this was not the case for approach movements. Based on these findings, it is suggested that approach/avoidance motor actions influence memory encoding by increasing the ease of processing for valence-compatible information.     

Finding needles in haystacks: identity mismatch frequency and facial identity verification

Accurate person identification is central to all security, police, and judicial systems. A commonplace method to achieve this is to compare a photo-ID and the face of its purported owner. The critical aspect of this task is to spot cases in which these two instances of a face do not match. Studies of person identification show that these instances often go undetected when mismatches occur regularly in an experiment, but this differs from everyday operations in which identity mismatches are rare. The current study therefore examined whether infrequent identity mismatches are more likely to go undetected by observers. In Experiments 1 and 2, identity mismatches were detected equally under low (2%) and high (50%) mismatch prevalence. This pattern persisted when viewing conditions were optimized for person identification in Experiment 3, by using a card-sorting task in which all face identities could be viewed repeatedly, and also under increased task difficulty, by constraining viewing conditions temporally in Experiment 4. These results imply that the infrequent occurrence of identity mismatches in security settings such as passport control does not impair an observer's ability to detect these important events.     

Software tools for creating line drawings on a CRT

A software package that can be used for the generation of line drawings on CRTs is discussed. The pictures obtained are stored as sets of coordinates of line segments. Complex pictures consist of sets of subpictures. In this way, pictures, or parts of pictures, can be easily manipulated (e.g., rotated, translated, scaled) and can be displayed on different types of display systems.     

Perceptual biases in processing facial identity and emotion

Normal observers demonstrate a bias to process the left sides of faces during perceptual judgments about identity or emotion. This effect suggests a right cerebral hemisphere processing bias. To test the role of the right hemisphere and the involvement of configural processing underlying this effect, young and older control observers and patients with right hemisphere damage completed two chimeric faces tasks (emotion judgment and face identity matching) with both upright and inverted faces. For control observers, the emotion judgment task elicited a strong left-sided perceptual bias that was reduced in young controls and eliminated in older controls by face inversion. Right hemisphere damage reversed the bias, suggesting the right hemisphere was dominant for this task, but that the left hemisphere could be flexibly recruited when right hemisphere mechanisms are not available or dominant. In contrast, face identity judgments were associated most clearly with a vertical bias favouring the uppermost stimuli that was eliminated by face inversion and right hemisphere lesions. The results suggest these tasks involve different neurocognitive mechanisms. The role of the right hemisphere and ventral cortical stream involvement with configural processes in face processing is discussed.     

Examinations of identity invariance in facial expression adaptation

Faces provide a wealth of information essential to social interaction, including both static features, such as identity, and dynamic features, such as emotional state. Classic models of face perception propose separate neural-processing routes for identity and facial expression (Bruce & Young, 1986), but more recent models suggest that these routes are not independent of each other (Calder & Young, 2005). Using a perceptual adaptation paradigm in the present study, we attempted to further examine the nature of the relation between the neural representations of identity and emotional expression. In Experiment 1, adaptation to the basic emotions of anger, surprise, disgust, and fear resulted in significantly biased perception away from the adapting expression. A significantly decreased aftereffect was observed when the adapting and the test faces differed in identity. With a statistical model that separated surface texture and reflectance from underlying expression geometry, Experiment 2 showed a similar decrease in adaptation when the face stimuli had identical underlying prototypical geometry but differed in the static surface features supporting identity. These results provide evidence that expression adaptation depends on perceptual features important for identity processing and thus suggest at least partly overlapping neural processing of identity and facial expression.     

Raised line drawings are spontaneously explored with a single finger

In this study we examine the strategies used by blindfolded subjects asked to freely explore raised line drawings and identify what is depicted in them. We were particularly interested in how often a single finger is spontaneously used because in several studies subjects are forced to use only one fingertip and the extent to which this restriction may depress haptic perception is unclear. The results suggest that despite a variety of strategies, people 'naturally' use single fingertips sufficiently often to allow confidence in conclusions that are based on studies imposing this restriction.     

The relationship between personality,ability to draw a person and the content of drawings

Seventy boys (aged 11 and 12) participated in an experiment designed to investigate the relationship between personality, drawing ability and the content of drawings. They were first asked to complete the Junior EPQ (Eysenck and Eysenck, 1973) then to draw a person and finally to draw anything at all. Three independent raters assessed the quality and bizarre content of the ‘person’ drawings; both drawings were then considered together and the judges rated the extent to which they were aggressive, imaginative, comic and sexually daring. The main finding was a significant correlation between ‘Psychoticism’ and bizarre content.     

Matching familiar and unfamiliar faces on identity and expression

Summary Subjects were asked to decide whether or not simultaneously presented photographs of pairs of faces were pictures of the same person or of different people (identity matching), or to decide whether or not the pairs of face showed the same expressions or different expressions (expression matching). Faces of familiar and unfamiliar people were used as stimuli. For identity matching, reaction times to familiar faces were faster than reaction times to unfamiliar faces, but there was no difference between familiar and unfamiliar faces for expression matching. These results support the view derived from neuropsychological and neurophysiological studies that analyses of facial expressions proceed independently from processes involved in establishing the person's identity.This research was supported by the ESRC (Grant C 0023 2075)     

Affective reactions to facial identity in a prosopagnosic patient

This study probes whether a prosopagnosic patient can make accurate explicit affective judgements towards faces. Patient MJH was shown photographs of faces of well-liked family members and public figures rated as “evil” by opinion polls. MJH was asked to rate each face on two 7-point scales (Likeability and Pleasantness). Since he is unable to explicitly recognise faces, his ratings were based on his evaluative reaction to the faces presented. In a second phase of the experiment, MJH was told the name of the faces previously presented and asked to rate them using the same scales. MJH's Likeability ratings during the picture-viewing phase of the experiment and the explicit phase were highly correlated. Based on these findings, we propose that thought consists of an explicit declarative and an implicit emotional aspect, which may become dissociated in prosopagnosia.     

Selective attention to facial identity and emotion in children

Three age groups of participants (6–8 years, 9–11 years, adults) performed two tasks: A face recognition task and a Garner task. In the face recognition task, the participants were presented with 20 faces and then had to recognize them among 20 new faces. In the Garner tasks, the participants had to sort, as fast as possible, the photographs of two persons expressing two emotions by taking into account only one of the two dimensions (identity or emotion). When the sorting task was on one dimension, the other dimension was varied either in a correlated, a constant or an orthogonal way in distinct subsessions. The results indicated an increase in face recognition abilities. They also showed an interference of identity in the emotion-sorting task that was similar in the three age groups. Nevertheless, an interference of emotion in the identity-sorting task was significant only for the children and was more important for the youngest group. These observations suggest that the development in face recognition ability rests on the development of the ability to attend selectively to identity, without paying attention to emotional facial expression.     

Verbal descriptions of spatial relations in line drawings by young children

A study of the ability of children to describe verbally spatial relations depicted in line drawings was carried out. The subjects were 60 children between the ages of 4 1/2 and 7 1/2 years. The test material consisted of 27 cards. Each card had one or two lines and a circle drawn on it. The lines and the circle were drawn in different spatial relations to one another. The results show that the ability of children to describe such spatial relations improves with increasing age. Furthermore, comparison between scores obtained from the children's own verbalizations and those obtained from a test of the ability to comprehend verbal material describing the spatial relations in the same drawings showed that there were no significant differences in the accuracy of response in any age group. The study also analyses the words most frequently used by the children in describing the cards, as well as the correct usage of such words. Some theoretical implications of the findings are discussed.     

Lateral asymmetries in the naming of words and corresponding line drawings

Laterally displaced line drawings and the words which name these drawings were tachistoscopically presented to adult subjects. For words, as expected, a right visual field-left hemisphere advantage was obtained. For line drawings, in contrast to previous studies which have typically reported a right visual field-left hemisphere advantage, no visual field asymmetry was found. The absence of a visual field asymmetry for line drawings is consistent with reports of a shift toward greater right hemisphere involvement in the recognition of pictographic as compared to phonetic writing systems and concrete/imageable words as compared to abstract/nonimageable words. Further, the present results seem consistent with findings on picture recognition and naming abilities in brain-damaged patients.     

Selective attention in vision: recognition memory for superimposed line drawings

These experiments show that observers can selectively attend to one of two stationary superimposed pictures. If superimposed line drawings are presented to observers who are told to attend to one line drawing in the pair and to ignore the other line drawing in the pair, then a subsequent recognition test in which the pictures are presently singly, the attended picture in each pair is recognized much more frequently than the unattended picture in each pair. This selective recognition occurs both with large (11 degrees-22 degrees) displays in which observers are free to make eye movements during a 3-sec exposure and with small (1 degree) displays in which observers are instructed to fixate steadily on a point during a 1-sec exposure. The results of the steady fixation experiments show that in the absence of eye movements, attention to one of two superimposed stimuli can cause an observer to remember the attended image and not to remember the other, clearly visible, unattended image in a superimposed pair.     

Infants recognize identity in a dynamic facial animation that simultaneously changes its identity and expression

Recognition of facial identity and facial expression have been reported to be correlated. Previous studies using static facial photographs reported that identity recognition was not interfered by task-irrelevant change of facial expression but that expression recognition was interfered by task-irrelevant change of facial identity. In this study, we created dynamic morphing animations that simultaneously changes facial identity and expression to investigate the interaction between identity and expression recognition. We tested 7 –8-month-old infants who were around the age at which the recognition of facial expression develops. Using the familiarization–novelty preference procedure, we examined whether infants could learn identity and facial expression from morphing animation. We found that infants learned identity but not expression from the morphing animation. Our results demonstrate that the interaction between identity and expression occurs differently in infancy than in adults when both the dimension of facial identity and the expression vary simultaneously.     

Sex-role identity as a moderator of the polarization effect in person perception

Male and female subjects with different sex-role identities (Androgynous, Masculine, Feminine, Undifferentiated) rated likability of male and female stimulus persons in the impression formation paradigm. Under certain conditions all the female subjects and feminine males manifested a polarization effect; that is, they made more polar ratings of opposite-sexed stimulus persons in contrast to same-sexed stimulus persons. On the other hand, under certain conditions Masculinetyped males rated male stimulus persons more negatively than female stimulus persons. Results were discussed in terms of moderating effects on the polarization phenomenon and possible explanatory mechanisms.