Mike Coleman

Face and emotion recognition deficits in Turner syndrome: a possible role for X-linked genes in amygdala development.

Face recognition is thought to rely on configural visual processing. Where face recognition impairments have been identified, qualitatively delayed or anomalous configural processing has also been found. A group of women with Turner syndrome (TS) with monosomy for a single maternal X chromosome (45, Xm) showed an impairment in face recognition skills compared with normally developing women. However, normal configural face-processing abilities were apparent. The ability to recognize facial expressions of emotion, particularly fear, was also impaired in this TS subgroup. Face recognition and fear recognition accuracy were significantly correlated in the female control group but not in women with TS. The authors therefore suggest that anomalies in amygdala function may be a neurological feature of TS of this karyotype.

Selective Attention and Perceptual Load in Autism Spectrum Disorder

It has been suggested that the locus of selective attention (early vs. late in processing) is dependent on the perceptual load of the task. When perceptual load is low, irrelevant distractors are processed (late selection), whereas when perceptual load is high, distractor interference disappears (early selection). Attentional abnormalities have long been reported within autism spectrum disorder (ASD), and this study is the first to examine the effect of perceptual load on selective attention in this population. Fourteen adults with ASD and 23 adults without ASD performed a selective attention task with varying perceptual loads. Compared with the non-ASD group, the ASD group required higher levels of perceptual load to successfully ignore irrelevant distractors; moreover, the ASD group did not show any general reduction in performance speed or accuracy. These results suggest enhanced perceptual capacity in the ASD group and are consistent with previous observations regarding superior visual search abilities among individuals with ASD.

An investigation of basic facial expression recognition in autism spectrum disorders

This study was designed to test three competing hypotheses (impaired configural processing; impaired Theory of Mind; atypical amygdala functioning) to explain the basic facial expression recognition profile of adults with autism spectrum disorders (ASD). In Experiment 1 the Ekman and Friesen (1976) series were presented upright and inverted. Individuals with ASD were significantly less accurate than controls at recognising upright facial expressions of fear, sadness and disgust and their pattern of errors suggested some configural processing difficulties. Impaired recognition of inverted facial expressions suggested some additional difficulties processing the facial features. Unexpectedly, the clinical group misidentified fear as anger. In Experiment 2 feature processing of facial expressions was investigated by presenting stimuli in a piecemeal fashion, starting with either just the eyes or the mouth. Individuals with ASD were impaired at recognising fear from the eyes and disgust from the mouth; they also confused fearful eyes as being angry. The findings are discussed in terms of the three competing hypotheses tested.

Development of motion processing in children with autism

Recent findings suggest that children with autism may be impaired in the perception of biological motion from moving point-light displays. Some children with autism also have abnormally high motion coherence thresholds. In the current study we tested a group of children with autism and a group of typically developing children aged 5 to 12 years of age on several motion perception tasks, in order to establish the specificity of the biological motion deficit in relation to other visual discrimination skills. The first task required the recognition of biological from scrambled motion. Three quasi-psychophysical tasks then established individual thresholds for the detection of biological motion in dynamic noise, of motion coherence and of form-from-motion. Lastly, individual thresholds for a task of static perception--contour integration (Gabor displays)--were also obtained. Compared to controls, children with autism were particularly impaired in processing biological motion in relation to any developmental measure (chronological or mental age). In contrast, there was some developmental overlap in ability to process other types of visual motion between typically developing children and the children with autism, and evidence of developmental change in both groups. Finally, Gabor display thresholds appeared to develop typically in children with autism.

When does the Inner-face Advantage in Familiar Face Recognition Arise and Why?

Known faces are recognized better from their inner than outer parts (Ellis, Shepherd, & Davies, 1979). This has previously been demonstrated with cropped images. Using a blurring technique to defocus different parts of the face image systematically, we confirmed the effect for adults viewing famous faces (Experiment1). Children aged 5–13 years showed an outer-face advantage (Experiments 2 and 3). The inner-face advantage was found only at 15 years (Experiment 3). Experiment 4 showed an outer-face advantage in familiar face recognition when the viewers were adolescents with a mental age of under 10 years. The emergence of the inner-face advantage is a developmental rather than a maturational phenomenon. We discuss the implications of the failure to show a qualitatively adult-like pattern of face recognition before adolescence in relation to theories and models of face recognition.

Recognizing people from the inner or outer parts of their faces: developmental data concerning 'unfamiliar' faces

Existing data demonstrate a developmental trend in the way in which highly familiar faces are recognized, such that young children rely more on the outer facial features (the hairline, chin and ears) than the inner facial features (the eyes, nose and mouth) and adults demonstrate the reverse pattern. However, little is known about the developmental pattern of importance of inner and outer facial features for recognizing people who are not highly familiar. Here we report a study which attempts to describe this pattern. Using a two-alternative forced-choice procedure, we presented 5-, 7-, and 9-year-olds and adults (N = 22 in each group) with the task of recognizing an experimentally familiarized face (initially seen in a short video) from a still picture of either the whole face, just the inner, or just the outer parts. The results showed that, for all ages, recognition was faster (and in most cases, more accurate) for outer features alone than for inner features alone (and was fastest for whole faces). These data demonstrate the importance of outer facial features for the recognition of relatively unfamiliar faces. Taken together with previous findings, they enhance our picture of the effects of age and experience with individual faces on recognition and configural processing.

The Noh mask effect: vertical viewpoint dependence of facial expression perception

Full-face masks, worn by skilled actors in the Noh tradition, can induce a variety of perceived expressions with changes in head orientation. Out-of-plane rotation of the head changes the two-dimensional image characteristics of the face which viewers may misinterpret as non-rigid changes due to muscle action. Three experiments with Japanese and British viewers explored this effect. Experiment 1 confirmed a systematic relationship between vertical angle of view of a Noh mask and judged affect. A forward tilted mask was more often judged happy, and one backward tilted more often judged sad. This effect was moderated by culture. Japanese viewers ascribed happiness to the mask at greater degrees of backward tilt with a reversal towards sadness at extreme forward angles. Cropping the facial image of chin and upper head contour reduced the forward-tilt reversal. Finally, the relationship between head tilt and affect was replicated with a laser-scanned human face image, but with no cultural effect. Vertical orientation of the head changes the apparent disposition of facial features and viewers respond systematically to these changes. Culture moderates this effect, and we discuss how perceptual strategies for ascribing expression to familiar and unfamiliar images may account for the differences.

Face and object processing in autism spectrum disorders

The nature and extent of face‐processing impairments in individuals with autism spectrum disorder (ASD) remain contentious. The aim of this research study is to assess the face‐ and object‐processing performance of individuals with ASD compared with typically developing controls. Our hypothesis was that individuals with ASD would be significantly impaired on tests of face processing but show intact object processing. More specifically, we tested two competing hypotheses to explain face‐processing deficits: holistic hypothesis; second‐order configural hypothesis. Twenty‐six able adults with ASD and 26 intelligence quotient‐matched typically developing controls completed two computerized tests of face and object discrimination. In task 1, the first picture (faces or cars) in a pair was presented as quickly as 40 msec to test holistic processing. In task 2, the decision was whether pairs of faces or houses had been altered in terms of the features or the distance between the features (the second‐order configural properties). Individuals with ASD were impaired on all tests of face processing but showed intact object processing and the pattern of findings favored the holistic hypothesis. The heterogeneous pattern of performance in the clinical group showed that some individuals with ASD perform similarly to typically developing individuals in their face‐processing skills, whereas others are more accurate in object processing compared with face processing.

Are faces of different species perceived categorically by human observers

What are the species boundaries of face processing? Using a face–feature morphing algorithm, image series intermediate between human, monkey (macaque), and bovine faces were constructed. Forced–choice judgement of these images showed sharply bounded categories for upright face images of each species. These predicted the perceptual discrimination boundaries for upright monkey–cow and cow–human images, but not human–monkey images. Species categories were also well–judged for inverted face images, but these did not give sharpened discrimination (categorical perception) at the category boundaries. While categorical species judgements are made reliably, only the distinction between primate faces and cow faces appears to be categorically perceived, and only in upright faces. One inference is that humans may judge monkey faces in terms of human characteristics, albeit distinctive ones.

More about brows: how poses that change brow position affect perceptions of gender.

The speeded categorisation of gender from photographs of mens and womens faces under conditions of vertical brow and vertical head movement was explored in two sets of experiments. These studies were guided by the suggestion that a simple cue to gender in faces, the vertical distance between the eyelid and brow, could support such decisions. In men this distance is smaller than in women, and can be further reduced by lowering the brows and also by lowering the head and raising the eyes to camera. How does the gender-classification mechanism take changes in pose into account? Male faces with lowered brows (experiment 1) were more quickly and accurately categorised (there was little corresponding ‘feminisation’ of raised-brow faces). Lowering gaze had a similar effect, but failed to interact with head lowering in a simple manner (experiment 2). We conclude that the initial classification of gender from the facial image may not involve normalisation of the face image to a canonical state (the ‘mug-shot view’) for expressive pose (brow movement and direction of gaze). For head pose (relative position of the features when the face is not viewed head-on), normalisation cannot be ruled out. Some perceptual mechanisms for these effects, and their functional implications, are discussed.