Angélique W. Hendriks

Assessment of perception of morphed facial expressions using the Emotion Recognition Task: Normative data from healthy participants aged 8–75

The ability to recognize and label emotional facial expressions is an important aspect of social cognition. However, existing paradigms to examine this ability present only static facial expressions, suffer from ceiling effects or have limited or no norms. A computerized test, the Emotion Recognition Task (ERT), was developed to overcome these difficulties. In this study, we examined the effects of age, sex, and intellectual ability on emotion perception using the ERT. In this test, emotional facial expressions are presented as morphs gradually expressing one of the six basic emotions from neutral to four levels of intensity (40%, 60%, 80%, and 100%). The task was administered in 373 healthy participants aged 8-75. In children aged 8-17, only small developmental effects were found for the emotions anger and happiness, in contrast to adults who showed age-related decline on anger, fear, happiness, and sadness. Sex differences were present predominantly in the adult participants. IQ only minimally affected the perception of disgust in the children, while years of education were correlated with all emotions but surprise and disgust in the adult participants. A regression-based approach was adopted to present age- and education- or IQ-adjusted normative data for use in clinical practice. Previous studies using the ERT have demonstrated selective impairments on specific emotions in a variety of psychiatric, neurologic, or neurodegenerative patient groups, making the ERT a valuable addition to existing paradigms for the assessment of emotion perception.

Evidence for magnocellular involvement in the identification of flanked letters

Little is known about the role of the magno system in reading. One important hypothesis is that this system is involved in the allocation of attention. We reasoned that the presentation of a single letter automatically draws attention to this letter, whereas in the case of a flanked letter, an additional process of attention allocation is required for identification to occur. In three letter-naming experiments with 24 subjects each, normally reading adults were presented with flanked (e.g. xax) and with single (e.g. a) letters at three possible (para)foveal locations. The letters appeared in magno-disadvantageous colour contrast or in parvo-disadvantageous weak luminance contrast with the background. A control experiment verified that colour contrast had generated less magnocellular activity than had luminance contrast. Colour-contrast presentation led to a significantly lower naming performance for flanked letters than did luminance-contrast presentation, despite the fact that the two contrasts did not elicit differences in naming performance when the letters were presented in isolation. This latter finding rules out the possibility that colour contrast had generated not only less magno- but also less parvocellular activity than had luminance contrast. Thus, it can be concluded that the magno system is involved in the identification of flanked letters. This conclusion supports the hypothesis that the magno system is important to the allocation of attention. Further, it may provide an explanation for the frequent finding that people with developmental dyslexia have impairments in their magnocellular system.

Assessment of theory of mind in children with communication disorders: role of presentation mode.

Children with communication disorders have problems with both language and social interaction. The theory-of-mind hypothesis provides an explanation for these problems, and different tests have been developed to test this hypothesis. However, different modes of presentation are used in these tasks, which make the results difficult to compare. In the present study, the performances of typically developing children, children with specific language impairments, and children with autism spectrum disorders were therefore compared using three theory-of-mind tests (the Charlie test, the Smarties test, and the Sally-and-Anne test) presented in three different manners each (spoken, video, and line drawing modes). The results showed differential outcomes for the three types of tests and a significant interaction between group of children and mode of presentation. For the typically developing children, no differential effects of presentation mode were detected. For the children with SLI, the highest test scores were consistently evidenced in the line-drawing mode. For the children with ASD, test performance depended on the mode of presentation. Just how the childrens non-verbal age, verbal age, and short-term memory related to their test scores was also explored for each group of children. The test scores of the SLI group correlated significantly with their short-term memory, those of the ASD group with their verbal age. These findings demonstrate that performance on theory-of-mind tests clearly depend upon mode of test presentation as well as the childrens cognitive and linguistic abilities.

Perception of dynamic facial emotional expressions in adolescents with autism spectrum disorders (ASD)

Previous studies have shown deficits in the perception of static emotional facial expressions in individuals with autism spectrum disorders (ASD), but results are inconclusive. Possibly, using dynamic facial stimuli expressing emotions at different levels of intensities may produce more robust results, since these resemble the expression of emotions in daily life to a greater extent. 30 Young adolescents with high-functioning ASD (IQ>85) and 30 age- and intelligence-matched controls (ages between 12 and 15) performed the Emotion Recognition Task, in which morphs were presented on a computer screen, depicting facial expressions of the six basic emotions (happiness, disgust, fear, anger, surprise and sadness) at nine levels of emotional intensity (20–100%). The results showed no overall group difference on the ERT, apart from a slightly worse performance on the perception of the emotions fear (p<0.03) and disgust (p<0.05). No interaction was found between intensity level of the emotions and group. High-functioning individuals with ASD perform similar to matched controls on the perception of dynamic facial emotional expressions, even at low intensities of emotional expression. These findings are in agreement with other recent studies showing that emotion perception deficits in high-functioning ASD may be less pronounced than previously thought.

The Effects of Mothers' Past Infant-Holding Preferences on Their Adult Children's Face Processing Lateralisation.

Face processing development is negatively affected when infants have not been exposed to faces for some time because of congenital cataract blocking all vision (Le Grand, Mondloch, Maurer, & Brent, 2001). It is not clear, however, whether more subtle differences in face exposure may also have an influence. The present study looked at the effect of the mothers preferred side of holding an infant, on her adult childs face processing lateralisation. Adults with a mother who had a left-arm preference for holding infants were compared with adults with a mother who had a right-arm holding preference. All participants were right-handed and had been exclusively bottle-fed during infancy. The participants were presented with two chimeric faces tests, one involving emotion and the other one gender. The left-arm held individuals showed a normal left-bias on the chimeric face tests, whereas the right-arm held individuals a significantly decreased left-bias. The results might suggest that reduced exposure to high quality emotional information on faces in infancy results in diminished right-hemisphere lateralisation for face processing.

The Interplay Between Attentional Strategies and Language Processing in High-functioning Adults with Autism Spectrum Disorder

This study examined the hypothesis of an atypical interaction between attention and language in ASD. A dual-task experiment with three conditions was designed, in which sentences were presented that contained errors requiring attentional focus either at (a) low level, or (b) high level, or (c) both levels of language. Speed and accuracy for error detection were measured from 16 high-functioning adults with ASD, and 16 matched controls. For controls, there was an attentional cost of dual level processing for low level performance but not for high level performance. For participants with ASD, there was an attentional cost both for low level and for high level performance. These results suggest a compensatory strategic use of attention during language processing in ASD.

Magnocellular involvement in flanked-letter identification relates to the allocation of attention.

To verify the hypothesis that the magnocellular system is important to flanked-letter identification [Neuropsychologia 40 (2002) 1881] because it subserves attention allocation, we conducted three letter-naming experiments in which we manipulated magnocellular involvement (colour vs. luminance contrast) and prior information regarding target-letter location. Location information was provided through constant presentation at the same location (Experiment 1) or through auditory precueing (Experiments 2 and 3). In control conditions, either no (Experiments 1 and 3) or invalid (Experiment 2) location information was given. In line with the hypothesis, magnocellular input helped flanked-letter identification only when no prior location information was given.

Magnocellular facilitation of flanked-letter identification disappears with strong flanker interference

Previously, we obtained evidence to suggest that the magnocellular system may reduce interference from flankers during flanked-letter identification. To understand this phenomenon better, we combined the data of our previous experiments, which all used the same flanking letter, and focused on the different target letters that were used. The new analysis showed that after an initial increase, magnocellular facilitation decreased and ultimately disappeared, as the target–flanker combinations level of interference increased. The initial increase was partly while the later decrease was fully replicated in two new experiments that focused on two different target letters while manipulating flanker identity. The outcome of a third new experiment studying the type of interference reduced suggested that although crowding contributed to total interference, it was insensitive to magnocellular mediation. Our results may be understood to reflect the involvement of the magnocellular system in an attentional-selection mechanism that is silenced by surround suppression.