The design and implementation of a CBT-based intervention for sensory processing difficulties in adolescents on the autism spectrum

BACKGROUND

Unusual reactions to sensory input now form part of the diagnostic criteria for autism. These features are common and can have an often-devastating impact on autistic individuals and their families. Yet there are few validated interventions that help to remediate or support autistic individuals' adverse sensory experiences. To date, both measurement of sensory experiences and the resulting interventions have been based on assumptions of neurological sensitivities and largely ignored the role of cognition. This study therefore sought to assess the feasibility of a new 8-week CBT-based group intervention for self-regulation of sensory processing difficulties.

METHOD

Seven cognitively able adolescents diagnosed with autism aged 11-16 years from one mainstream secondary school received the 8-week intervention. Measures of sensory reactivity, anxiety and repetitive behaviours were taken at baseline, post-intervention and follow-up, 8 weeks after the intervention had ceased. Semi-structured interviews and focus groups were also conducted with adolescents and their parents to examine further the acceptability of the intervention.

RESULTS

The results showed that the intervention itself was feasible - both in its implementation and its acceptability to participants. Qualitative analysis clearly showed that the intervention was effective in raising meta-conscious awareness and self-regulation in these autistic adolescents. Analysis of outcome variables showed no significant change over the intervention period, although effect sizes were moderate-to-large.

CONCLUSIONS

These preliminary results are encouraging and should inform the design of a future pilot randomized controlled trial to test its efficacy with a larger group of participants.

Holistic Processing of Faces in Preschool Children and Adults

Contrary to the encoding-switch hypothesis, recent research demonstrates that 6-year-olds do not rely solely on parts-based encoding to recognize upright faces. This research shows better recognition of face parts presented in the whole face than in isolation, indicating use of holistic encoding. The present study examined whether children younger than 6 years also recognize faces holistically. Four-year-olds, 5-year-olds, and adults were administered a part-whole face recognition task. Children below the age of 6 remembered parts from upright faces better when tested in the whole-face context than in isolation. This whole-face advantage did not occur when faces were inverted. Although children showed a smaller inversion decrement than adults and generally performed more poorly than adults, the different age groups showed similar patterns of performance, indicating that young preschoolers, like older children and adults, are able to recognize faces holistically.

Reputation Management in Children on the Autism Spectrum

Being able to manage reputation is an important social skill, but it is unclear whether autistic children can manage reputation. This study investigated whether 33 autistic children matched to 33 typical children could implicitly or explicitly manage reputation. Further, we examined whether cognitive processes—theory of mind, social motivation, inhibitory control and reciprocity—contribute to reputation management. Results showed that neither group implicitly managed reputation, and there was no group difference in explicit reputation management. Results suggested different mechanisms contribute to reputation management in these groups—social motivation in typical children and reciprocity in autistic children. Explicit reputation management is achievable for autistic children, and there are individual differences in its relationship to underlying cognitive processes.

Children on the autism spectrum update their behaviour in response to a volatile environment

Typical adults can track reward probabilities across trials to estimate the volatility of the environment and use this information to modify their learning rate (Behrens et al., 2007). In a stable environment, it is advantageous to take account of outcomes over many trials, whereas in a volatile environment, recent experience should be more strongly weighted than distant experience. Recent predictive coding accounts of autism propose that autistic individuals will demonstrate atypical updating of their behaviour in response to the statistics of the reward environment. To rigorously test this hypothesis, we administered a developmentally appropriate version of Behrens et al.'s (2007) task to 34 cognitively able children on the autism spectrum aged between 6 and 14 years, 32 age- and ability-matched typically developing children and 19 typical adults. Participants were required to choose between a green and a blue pirate chest, each associated with a randomly determined reward value between 0 and 100 points, with a combined total of 100 points. On each trial, the reward was given for one stimulus only. In the stable condition, the ratio of the blue or green response being rewarded was fixed at 75:25. In the volatile condition, the ratio alternated between 80:20 and 20:80 every 20 trials. We estimated the learning rate for each participant by fitting a delta rule model and compared this rate across conditions and groups. All groups increased their learning rate in the volatile condition compared to the stable condition. Unexpectedly, there was no effect of group and no interaction between group and condition. Thus, autistic children used information about the statistics of the reward environment to guide their decisions to a similar extent as typically developing children and adults. These results help constrain predictive coding accounts of autism by demonstrating that autism is not characterized by uniform differences in the weighting of prediction error.

Central tendency effects in time interval reproduction in autism

Central tendency, the tendency of judgements of quantities (lengths, durations etc.) to gravitate towards their mean, is one of the most robust perceptual effects. A Bayesian account has recently suggested that central tendency reflects the integration of noisy sensory estimates with prior knowledge representations of a mean stimulus, serving to improve performance. The process is flexible, so prior knowledge is weighted more heavily when sensory estimates are imprecise, requiring more integration to reduce noise. In this study we measure central tendency in autism to evaluate a recent theoretical hypothesis suggesting that autistic perception relies less on prior knowledge representations than typical perception. If true, autistic children should show reduced central tendency than theoretically predicted from their temporal resolution. We tested autistic and age- and ability-matched typical children in two child-friendly tasks: (1) a time interval reproduction task, measuring central tendency in the temporal domain; and (2) a time discrimination task, assessing temporal resolution. Central tendency reduced with age in typical development, while temporal resolution improved. Autistic children performed far worse in temporal discrimination than the matched controls. Computational simulations suggested that central tendency was much less in autistic children than predicted by theoretical modelling, given their poor temporal resolution.

Understanding parents’ and professionals’ knowledge and awareness of autism in Nepal

Autism is a global phenomenon. Yet, there is a dearth of knowledge of how it is understood and its impact in low-income countries. We examined parents’ and professionals’ understanding of autism in one low-income country, Nepal. We conducted focus groups and semi-structured interviews with parents of autistic and non-autistic children and education and health professionals from urban and rural settings ( n = 106), asking questions about typical and atypical development and presenting vignettes of children to prompt discussion. Overall, parents of typically developing children and professionals had little explicit awareness of autism. They did, however, use some distinctive terms to describe children with autism from children with other developmental conditions. Furthermore, most participants felt that environmental factors, including in-utero stressors and birth complications, parenting style and home or school environment were key causes of atypical child development and further called for greater efforts to raise awareness and build community capacity to address autism. This is the first study to show the striking lack of awareness of autism by parents and professionals alike. These results have important implications for future work in Nepal aiming both to estimate the prevalence of autism and to enhance support available for autistic children and their families.

Recognizing the same face in different contexts: Testing within-person face recognition in typical development and in autism

Unfamiliar face recognition follows a particularly protracted developmental trajectory and is more likely to be atypical in children with autism than those without autism. There is a paucity of research, however, examining the ability to recognize the same face across multiple naturally varying images. Here, we investigated within-person face recognition in children with and without autism. In Experiment 1, typically developing 6- and 7-year-olds, 8- and 9-year-olds, 10- and 11-year-olds, 12- to 14-year-olds, and adults were given 40 grayscale photographs of two distinct male identities (20 of each face taken at different ages, from different angles, and in different lighting conditions) and were asked to sort them by identity. Children mistook images of the same person as images of different people, subdividing each individual into many perceived identities. Younger children divided images into more perceived identities than adults and also made more misidentification errors (placing two different identities together in the same group) than older children and adults. In Experiment 2, we used the same procedure with 32 cognitively able children with autism. Autistic children reported a similar number of identities and made similar numbers of misidentification errors to a group of typical children of similar age and ability. Fine-grained analysis using matrices revealed marginal group differences in overall performance. We suggest that the immature performance in typical and autistic children could arise from problems extracting the perceptual commonalities from different images of the same person and building stable representations of facial identity.

No rapid audiovisual recalibration in adults on the autism spectrum

Autism spectrum disorders (ASD) are characterized by difficulties in social cognition, but are also associated with atypicalities in sensory and perceptual processing. Several groups have reported that autistic individuals show reduced integration of socially relevant audiovisual signals, which may contribute to the higher-order social and cognitive difficulties observed in autism. Here we use a newly devised technique to study instantaneous adaptation to audiovisual asynchrony in autism. Autistic and typical participants were presented with sequences of brief visual and auditory stimuli, varying in asynchrony over a wide range, from 512 ms auditory-lead to 512 ms auditory-lag, and judged whether they seemed to be synchronous. Typical adults showed strong adaptation effects, with trials proceeded by an auditory-lead needing more auditory-lead to seem simultaneous, and vice versa. However, autistic observers showed little or no adaptation, although their simultaneity curves were as narrow as the typical adults. This result supports recent Bayesian models that predict reduced adaptation effects in autism. As rapid audiovisual recalibration may be fundamental for the optimisation of speech comprehension, recalibration problems could render language processing more difficult in autistic individuals, hindering social communication.

Flexible integration of visual cues in adolescents with autism spectrum disorder

Although children with autism spectrum disorder (ASD) show atypical sensory processing, evidence for impaired integration of multisensory information has been mixed. In this study, we took a Bayesian model-based approach to assess within-modality integration of congruent and incongruent texture and disparity cues to judge slant in typical and autistic adolescents. Human adults optimally combine multiple sources of sensory information to reduce perceptual variance but in typical development this ability to integrate cues does not develop until late childhood. While adults cannot help but integrate cues, even when they are incongruent, young children's ability to keep cues separate gives them an advantage in discriminating incongruent stimuli. Given that mature cue integration emerges in later childhood, we hypothesized that typical adolescents would show adult-like integration, combining both congruent and incongruent cues. For the ASD group there were three possible predictions (1) "no fusion": no integration of congruent or incongruent cues, like 6-year-old typical children; (2) "mandatory fusion": integration of congruent and incongruent cues, like typical adults; (3) "selective fusion": cues are combined when congruent but not incongruent, consistent with predictions of Enhanced Perceptual Functioning (EPF) theory. As hypothesized, typical adolescents showed significant integration of both congruent and incongruent cues. The ASD group showed results consistent with "selective fusion," integrating congruent but not incongruent cues. This allowed adolescents with ASD to make perceptual judgments which typical adolescents could not. In line with EPF, results suggest that perception in ASD may be more flexible and less governed by mandatory top-down feedback.

The effects of grouping on speed discrimination thresholds in adults, typically developing children, and children with autism

Adult observers show elevated speed discrimination thresholds when comparing the speeds of objects moving across a boundary compared to those moving parallel to a boundary (Verghese & McKee, 2006)-an effect that has been attributed to grouping processes in conjunction with a prior for smooth motion. Here, we extended Verghese and McKee's (2006) paradigm to typically developing children (n = 35) and children with autism (n = 26) and compared their performance with that of typical adults (n = 19). Speed discrimination thresholds were measured in three conditions: (a) with dots moving parallel to a boundary, (b) with dots moving perpendicular to a boundary, and (c) with dots in each stimulus half moving in orthogonal, oblique directions. As expected, participants had higher speed discrimination thresholds when dots appeared to cross a boundary compared to when dots moved parallel to the boundary. However, participants had even higher thresholds when dots moved in oblique, orthogonal directions, where grouping should be minimal. All groups of participants showed a similar pattern of performance across conditions although children had higher thresholds than adult participants overall. We consider various explanations for the pattern of performance obtained, including enhanced sensitivity for shearing motions and reduced sensitivity for discriminating different directions. Our results demonstrate that the speed discrimination judgments of typically developing children and children with autism are similarly affected by spatial configuration as those of typical adults and provide further evidence that speed discrimination is unimpaired in children with autism.

Which terms should be used to describe autism? Perspectives from the UK autism community

Recent public discussions suggest that there is much disagreement about the way autism is and should be described. This study sought to elicit the views and preferences of UK autism community members – autistic people, parents and their broader support network – about the terms they use to describe autism. In all, 3470 UK residents responded to an online survey on their preferred ways of describing autism and their rationale for such preferences. The results clearly show that people use many terms to describe autism. The most highly endorsed terms were ‘autism’ and ‘on the autism spectrum’, and to a lesser extent, ‘autism spectrum disorder’, for which there was consensus across community groups. The groups disagreed, however, on the use of several terms. The term ‘autistic’ was endorsed by a large percentage of autistic adults, family members/friends and parents but by considerably fewer professionals; ‘person with autism’ was endorsed by almost half of professionals but by fewer autistic adults and parents. Qualitative analysis of an open-ended question revealed the reasons underlying respondents’ preferences. These findings demonstrate that there is no single way of describing autism that is universally accepted and preferred by the UK’s autism community and that some disagreements appear deeply entrenched.

Numerical Estimation in Children With Autism

Number skills are often reported anecdotally and in the mass media as a relative strength for individuals with autism, yet there are remarkably few research studies addressing this issue. This study, therefore, sought to examine autistic children's number estimation skills and whether variation in these skills can explain at least in part strengths and weaknesses in children's mathematical achievement. Thirty-two cognitively able children with autism (range = 8-13 years) and 32 typical children of similar age and ability were administered a standardized test of mathematical achievement and two estimation tasks, one psychophysical nonsymbolic estimation (numerosity discrimination) task and one symbolic estimation (numberline) task. Children with autism performed worse than typical children on the numerosity task, on the numberline task, which required mapping numerical values onto space, and on the test of mathematical achievement. These findings question the widespread belief that mathematical skills are generally enhanced in autism. For both groups of children, variation in performance on the numberline task was also uniquely related to their academic achievement, over and above variation in intellectual ability; better number-to-space mapping skills went hand-in-hand with better arithmetic skills. Future research should further determine the extent and underlying causes of some autistic children's difficulties with regards to number.

Atypicalities in perceptual adaptation in autism do not extend to perceptual causality

A recent study showed that adaptation to causal events (collisions) in adults caused subsequent events to be less likely perceived as causal. In this study, we examined if a similar negative adaptation effect for perceptual causality occurs in children, both typically developing and with autism. Previous studies have reported diminished adaptation for face identity, facial configuration and gaze direction in children with autism. To test whether diminished adaptive coding extends beyond high-level social stimuli (such as faces) and could be a general property of autistic perception, we developed a child-friendly paradigm for adaptation of perceptual causality. We compared the performance of 22 children with autism with 22 typically developing children, individually matched on age and ability (IQ scores). We found significant and equally robust adaptation aftereffects for perceptual causality in both groups. There were also no differences between the two groups in their attention, as revealed by reaction times and accuracy in a change-detection task. These findings suggest that adaptation to perceptual causality in autism is largely similar to typical development and, further, that diminished adaptive coding might not be a general characteristic of autism at low levels of the perceptual hierarchy, constraining existing theories of adaptation in autism.

Views on researcher-community engagement in autism research in the United Kingdom: a mixed-methods study

There has been a substantial increase in research activity on autism during the past decade. Research into effective ways of responding to the immediate needs of autistic people is, however, less advanced, as are efforts at translating basic science research into service provision. Involving community members in research is one potential way of reducing this gap. This study therefore investigated the views of community involvement in autism research both from the perspectives of autism researchers and of community members, including autistic adults, family members and practitioners. Results from a large-scale questionnaire study (n = 1,516) showed that researchers perceive themselves to be engaged with the autism community but that community members, most notably autistic people and their families, did not share this view. Focus groups/interviews with 72 participants further identified the potential benefits and remaining challenges to involvement in research, especially regarding the distinct perspectives of different stakeholders. Researchers were skeptical about the possibilities of dramatically increasing community engagement, while community members themselves spoke about the challenges to fully understanding and influencing the research process. We suggest that the lack of a shared approach to community engagement in UK autism research represents a key roadblock to translational endeavors.

What should autism research focus upon? Community views and priorities from the United Kingdom

The rise in the measured prevalence of autism has been accompanied by much new research and research investment internationally. This study sought to establish whether the pattern of current UK autism research funding maps on to the concerns of the autism community. Interviews and focus groups were conducted with autistic adults, family members, practitioners and researchers to identify their priorities for research. We also captured the views of a large number of stakeholders via an online survey. There was a clear disparity between the United Kingdom's pattern of funding for autism research and the priorities articulated by the majority of participants. There was general consensus that future priorities for autism research should lie in those areas that make a difference to people's day-to-day lives. There needs to be greater involvement of the autism community both in priority setting and in research more broadly to ensure that resources reach where they are most needed and can make the most impact.

Averaging, not internal noise, limits the development of coherent motion processing

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Motion processing abilities develop gradually through childhood.

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This lengthy development could be due to local noise and/or poor averaging.

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5–11-year-olds and adults performed equivalent noise and motion coherence tasks.

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Through childhood, internal noise reduces and averaging increases.

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Yet, only improved averaging explains developments in motion coherence sensitivity.

The development of motion processing is a critical part of visual development, allowing children to interact with moving objects and navigate within a dynamic environment. However, global motion processing, which requires pooling motion information across space, develops late, reaching adult-like levels only by mid-to-late childhood. The reasons underlying this protracted development are not yet fully understood. In this study, we sought to determine whether the development of motion coherence sensitivity is limited by internal noise (i.e., imprecision in estimating the directions of individual elements) and/or global pooling across local estimates. To this end, we presented equivalent noise direction discrimination tasks and motion coherence tasks at both slow (1.5°/s) and fast (6°/s) speeds to children aged 5, 7, 9 and 11 years, and adults. We show that, as children get older, their levels of internal noise reduce, and they are able to average across more local motion estimates. Regression analyses indicated, however, that age-related improvements in coherent motion perception are driven solely by improvements in averaging and not by reductions in internal noise. Our results suggest that the development of coherent motion sensitivity is primarily limited by developmental changes within brain regions involved in integrating motion signals (e.g., MT/V5).

The Cambridge Face Memory Test for Children (CFMT-C): a new tool for measuring face recognition skills in childhood

Face recognition ability follows a lengthy developmental course, not reaching maturity until well into adulthood. Valid and reliable assessments of face recognition memory ability are necessary to examine patterns of ability and disability in face processing, yet there is a dearth of such assessments for children. We modified a well-known test of face memory in adults, the Cambridge Face Memory Test (Duchaine & Nakayama, 2006, Neuropsychologia, 44, 576-585), to make it developmentally appropriate for children. To establish its utility, we administered either the upright or inverted versions of the computerised Cambridge Face Memory Test - Children (CFMT-C) to 401 children aged between 5 and 12 years. Our results show that the CFMT-C is sufficiently sensitive to demonstrate age-related gains in the recognition of unfamiliar upright and inverted faces, does not suffer from ceiling or floor effects, generates robust inversion effects, and is capable of detecting difficulties in face memory in children diagnosed with autism. Together, these findings indicate that the CFMT-C constitutes a new valid assessment tool for children's face recognition skills.

Reduced face aftereffects in autism are not due to poor attention

This study aimed to determine why face identity aftereffects are diminished in children with autism, relative to typical children. To address the possibility that reduced face aftereffects might reflect reduced attention to adapting stimuli, we investigated the consequence of controlling attention to adapting faces during a face identity aftereffect task in children with autism and typical children. We also included a size-change between adaptation and test stimuli to determine whether the reduced aftereffects reflect atypical adaptation to low- or higher-level stimulus properties. Results indicated that when attention was controlled and directed towards adapting stimuli, face identity aftereffects in children with autism were significantly reduced relative to typical children. This finding challenges the notion that atypicalities in the quality and/or quantity of children's attention during adaptation might account for group differences previously observed in this paradigm. Additionally, evidence of diminished face identity aftereffects despite a stimulus size change supports an adaptive processing atypicality in autism that extends beyond low-level, retinotopically coded stimulus properties. These findings support the notion that diminished face aftereffects in autism reflect atypicalities in adaptive norm-based coding, which could also contribute to face processing difficulties in this group.

Using effort to measure reward value of faces in children with autism

According to one influential account, face processing atypicalities in autism reflect reduced reward value of faces, which results in limited attention to faces during development and a consequent failure to acquire face expertise. Surprisingly, however, there is a paucity of work directly investigating the reward value of faces for individuals with autism and the evidence for diminished face rewards in this population remains equivocal. In the current study, we measured how hard children with autism would work to view faces, using an effortful key-press sequence, and whether they were sensitive to the differential reward value of attractive and unattractive faces. Contrary to expectations, cognitively able children with autism did not differ from typically developing children of similar age and ability in their willingness to work to view faces. Moreover, the effort expended was strongly positively correlated with facial attractiveness ratings in both groups of children. There was also no evidence of atypical reward values for other, less social categories (cars and inverted faces) in the children with autism. These results speak against the possibility that face recognition difficulties in autism are explained by atypical reward value of faces.

Processing slow and fast motion in children with autism spectrum conditions

Consistent with the dorsal stream hypothesis, difficulties processing dynamic information have previously been reported in individuals with autism spectrum conditions (ASC). However, no research has systematically compared motion processing abilities for slow and fast speeds. Here, we measured speed discrimination thresholds and motion coherence thresholds in slow (1.5 deg/sec) and fast (6 deg/sec) speed conditions in children with an ASC aged 7 to 14 years, and age- and ability-matched typically developing children. Unexpectedly, children with ASC were as sensitive as typically developing children to differences in speed at both slow and fast reference speeds. Yet, elevated motion coherence thresholds were found in children with ASC, but in the slow stimulus speed condition only. Rather than having pervasive difficulties in motion processing, as predicted by the dorsal stream hypothesis, these results suggest that children with ASC have a selective difficulty in extracting coherent motion information specifically at slow speeds. Understanding the effects of stimulus parameters such as stimulus speed will be important for resolving discrepancies between previous studies examining motion coherence thresholds in ASC and also for refining theoretical models of altered autistic perception.

Reputation management: evidence for ability but reduced propensity in autism

Previous research has reported that autistic adults do not manage their reputation, purportedly due to problems with theory of mind [Izuma, Matsumoto, Camerer, & Adolphs]. The current study aimed to test alternative explanations for this apparent lack of reputation management. Twenty typical and 19 autistic adults donated to charity and to a person, both when alone and when observed. In an additional manipulation, for half of the participants, the observer was also the recipient of their donations, and participants were told that this observer would subsequently have the opportunity to donate to them (motivation condition). This manipulation was designed to encourage an expectation of a reciprocal "tit-for-tat" strategy in the participant, which may motivate participants to change their behavior to receive more donations. The remaining participants were told that the person watching was just observing the procedure (no motivation condition). Our results replicated Izuma et al.'s finding that autistic adults did not donate more to charity when observed. Yet, in the motivation condition, both typical and autistic adults donated significantly more to the observer when watched, although this effect was significantly attenuated in autistic individuals. Results indicate that, while individuals with autism may have the ability to think about reputation, a reduced expectation of reciprocal behavior from others may reduce the degree to which they engage in reputation management.

Reduced gaze aftereffects are related to difficulties categorising gaze direction in children with autism

Perceptual mechanisms are generally flexible or "adaptive", as evidenced by perceptual aftereffects: distortions that arise following exposure to a stimulus. We examined whether adaptive mechanisms for coding gaze direction are atypical in children diagnosed with an autism spectrum condition. Twenty-four typical children and 24 children with autism, of similar age and ability, were administered a developmentally sensitive eye-gaze adaptation task. In the pre-adaptation phase, children judged whether target faces showing subtle deviations in eye-gaze direction were looking leftwards, rightwards or straight-ahead. Next, children were adapted to faces gazing in one consistent direction (25° leftwards/rightwards) before categorising the direction of the target faces again. Children with autism showed difficulties in judging whether subtle deviations in gaze were directed to the left, right or straight-ahead relative to typical children. Although adaptation to leftward or rightward gaze resulted in reduced sensitivity to gaze on the adapted side for both groups, the aftereffect was significantly reduced in children with autism. Furthermore, the magnitude of children's gaze aftereffects was positively related to their ability to categorise gaze direction. These results show that the mechanisms coding gaze are less flexible in autism and offer a potential new explanation for these children's difficulties discriminating subtle deviations in gaze direction.

Reevaluating the selectivity of face-processing difficulties in children and adolescents with autism

There are few direct examinations of whether face-processing difficulties in autism are disproportionate to difficulties with other complex non-face stimuli. Here we examined discrimination ability and memory for faces, cars, and inverted faces in children and adolescents with and without autism. Results showed that, relative to typical children, the difficulties of children and adolescents with autism were not limited to, or disproportionately severe for, faces. Rather, these participants demonstrated significant difficulties in remembering and discriminating between faces and cars. This lack of face selectivity is inconsistent with prominent theories that attribute face-processing difficulties in autism to fundamental problems with social motivation or social attention. Instead, our results are consistent with a more pervasive perceptual atypicality that may affect autistic processing of non-face stimuli as well as face stimuli.

Atypical updating of face representations with experience in children with autism

Face identity aftereffects are significantly diminished in children with autism relative to typical children, which may reflect reduced perceptual updating with experience. Here, we investigated whether this atypicality also extends to non-face stimulus categories, which might signal a pervasive visual processing difference in individuals with autism. We used a figural aftereffect task to measure directly perceptual updating following exposure to distorted upright faces, inverted faces and cars, in typical children and children with autism. A size-change between study and test stimuli limited the likelihood that any processing atypicalities reflected group differences in adaptation to low-level features of the stimuli. Results indicated that, relative to typical children, figural aftereffects for upright faces, but not inverted faces or cars, were significantly attenuated in children with autism. Moreover, the group difference was amplified when we isolated the 'face-selective' component of the aftereffect, by partialling out the mid-level shape adaptation common to upright and inverted face stimuli. Notably, the aftereffects of typical children were disproportionately larger for upright faces than for inverted faces and cars, but the magnitude of aftereffects of autistic children was not similarly modulated according to stimulus category. These findings are inconsistent with a pervasive adaptive coding atypicality relative to typical children, and suggest that reduced perceptual updating may constitute a high-level, and possibly face-selective, visual processing difference in children with autism.

'Sometimes I want to play by myself': Understanding what friendship means to children with autism in mainstream primary schools

Research has shown that friendship impacts the overall experience of mainstream school for autistic children. Using a unique combination of quantitative, qualitative and social network methods, we investigated the extent and nature of autistic children's friendships from their perspective and from those of their mothers, teachers and classroom peers. Consistent with previous research, children with autism (n = 12), aged between 9 and 11 years, rated their friendships to be of poorer quality than their non-autistic classroom peers (n = 11). There was, however, much variability in autistic children's ratings, which, unexpectedly, was related to neither children's cognitive ability nor their theory of mind ability. Encouragingly, the children generally reported satisfaction with their friendships, and although no child was socially isolated, the degree of inclusion in friendship networks varied widely. Furthermore, autistic children's social motivation emerged as a key factor in parents' and teachers' reports in determining both the nature and extent of their friendships. Adults played an active role in supporting children's friendships, but this sometimes conflicted with what the children wanted. These findings highlight the need to ascertain the perspectives of young people with autism on their friendships and to consider the social and ethical implications of when and how to intervene.

When the world becomes 'too real': a Bayesian explanation of autistic perception

Perceptual experience is influenced both by incoming sensory information and prior knowledge about the world, a concept recently formalised within Bayesian decision theory. We propose that Bayesian models can be applied to autism - a neurodevelopmental condition with atypicalities in sensation and perception - to pinpoint fundamental differences in perceptual mechanisms. We suggest specifically that attenuated Bayesian priors - 'hypo-priors' - may be responsible for the unique perceptual experience of autistic people, leading to a tendency to perceive the world more accurately rather than modulated by prior experience. In this account, we consider how hypo-priors might explain key features of autism - the broad range of sensory and other non-social atypicalities--in addition to the phenomenological differences in autistic perception.

Reduced face identity aftereffects in relatives of children with autism

Autism is a pervasive developmental condition with complex aetiology. To aid the discovery of genetic mechanisms, researchers have turned towards identifying potential endophenotypes - subtle neurobiological or neurocognitive traits present in individuals with autism and their "unaffected" relatives. Previous research has shown that relatives of individuals with autism exhibit face processing atypicalities, which are similar in nature albeit of lesser degree, to those found in children and adults with autism. Yet very few studies have examined the underlying mechanisms responsible for such atypicalities. Here, we investigated whether atypicalities in adaptive norm-based coding of faces are present in relatives of children with autism, similar to those previously reported in children with autism. To test this possibility, we administered a face identity aftereffect task in which adaptation to a particular face biases perception towards the opposite identity, so that a previously neutral face (i.e., the average face) takes on the computationally opposite identity. Parents and siblings of individuals with autism showed smaller aftereffects compared to parents and siblings of typically developing children, especially so when the adapting stimuli were located further away from the average face. In addition, both groups showed stronger aftereffects for adaptors far from the average than for adaptors closer to the average. These results suggest that, in relatives of children with autism, face-coding mechanism are similar (i.e., norm-based) but less efficient than in relatives of typical children. This finding points towards the possibility that diminished adaptive mechanisms might represent a neurocognitive endophenotype for autism.

The development of speed discrimination abilities

The processing of speed is a critical part of a child's visual development, allowing children to track and interact with moving objects. Despite such importance, no study has investigated the developmental trajectory of speed discrimination abilities or precisely when these abilities become adult-like. Here, we measured speed discrimination thresholds in 5-, 7-, 9-, 11-year-olds and adults using random dot stimuli with two different reference speeds (slow: 1.5 deg/s; fast: 6 deg/s). Sensitivity for both reference speeds improved exponentially with age and, at all ages, participants were more sensitive to the faster reference speed. However, sensitivity to slow speeds followed a more protracted developmental trajectory than that for faster speeds. Furthermore, sensitivity to the faster reference speed reached adult-like levels by 11 years, whereas sensitivity to the slower reference speed was not yet adult-like by this age. Different developmental trajectories may reflect distinct systems for processing fast and slow speeds. The reasonably late development of speed processing abilities may be due to inherent limits in the integration of neuronal responses in motion-sensitive areas in early childhood.

The development of executive function in autism

Autism is a common and often highly debilitating neurodevelopmental condition, whose core behavioral features are believed to be rooted in disrupted neurocognitive processes, including especially "executive function." Researchers have predominantly focused upon understanding the putative causal relationship between difficulties in EF and autistic symptomatology. This paper suggests, however, that the effects of individual differences in EF should be more far-reaching, playing a significant part in the real-life outcomes of individuals with autism, including their social competence, everyday adaptive behavior, and academic achievement. It further considers the nature of the EF-outcome relationship, including the possible determinants of individual differences in EF, and makes several recommendations for future research.

Do autistic symptoms persist across time? Evidence of substantial change in symptomatology over a 3-year period in cognitively able children with autism

This study investigated the extent and nature of changes in symptomatology in cognitively able children with autism over a 3-year period. Thirty-seven children diagnosed with an autism spectrum condition involved in an earlier study (M age  =  5 years, 7 months) were followed and reassessed 3 years later (M age  =  8 years, 4 months). Scores on the Social Communication Questionnaire (SCQ; M. Rutter, A. Bailey, & C. Lord, 2003 ) decreased significantly over time in all symptom domains but especially in the social domain, and correlational findings suggested the presence of 2 distinct developmental trajectories-social communication and repetitive behaviors-that interact across time. Furthermore, 7 children (19% of sample) made substantial changes to the extent that they failed to meet criteria on diagnostic instruments (the Autism Diagnostic Observation Schedule-Generic [ADOS-G; C. Lord, M. Rutter, P. C. DiLavore, & S. Risi, 1999 ] and the SCQ) 3 years later. Children showing diagnostic discontinuity were distinguishable from those who fulfilled ADOS-G criteria only in terms of the age at which they began receiving intervention. The presence of a significant proportion of children showing considerable progress over the 3-year period challenges assumptions of diagnostic continuity and highlights the potential long-term benefits of early intervention.

Bridging autism, science and society: moving toward an ethically informed approach to autism research

Recent developments in the science of autism have provoked widespread unease among autism activists. Drawing on the findings of a major international gathering of researchers, ethicists, and activists, this paper presents the first major analysis of the ethical questions arising from this unease. We outline the scientific developments that have provoked the most discomfort, analyze the response to these developments from within and without the autism community, and trace the current state of the ethical debate. Having done so, we contend that these ethical questions are unlikely to be resolved as they depend on fundamentally conflicting assumptions about the nature and desirability of neurocognitive difference. We conclude by arguing for a new range of democratic mechanisms that could enable the scientific community, autistics, and other concerned parties to respond collectively to such entrenched ethical disputes.

Face processing abilities in relatives of individuals with ASD

Individuals with an autism spectrum disorder (ASD) show difficulties identifying familiar faces, recognizing emotional expressions and judging eye-gaze direction. Recent research suggests that relatives of individuals with AS also show impairments in some aspects of face processing but no study has comprehensively assessed the nature and extent of face-processing difficulties in a group of relatives. This study compared the performance of 22 parents/adult siblings of individuals with ASD ("relatives" group), 26 adults with ASD, and 26 typically developing adults on tasks of face discrimination, facial expression recognition and judging eye-gaze direction. Relatives of individuals with ASD were less able to discriminate subtle differences between faces than typically developing adults, but were more sensitive to such differences than adults with ASD. Furthermore, relatives were significantly worse at identifying expressions of fear and disgust than typically developing adults and failed to show the typical sensitivity to direct compared with averted eye-gaze direction--a strikingly similar pattern to that observed in adults with ASD. These findings show that atypical patterns of face processing are found in some relatives of individuals with ASD and suggest that these difficulties may represent a cognitive endophenotype.

Perception of shapes targeting local and global processes in autism spectrum disorders

BACKGROUND

Several researchers have found evidence for impaired global processing in the dorsal visual stream in individuals with autism spectrum disorders (ASDs). However, support for a similar pattern of visual processing in the ventral visual stream is less consistent. Critical to resolving the inconsistency is the assessment of local and global form processing ability.

METHODS

Within the visual domain, radial frequency (RF) patterns - shapes formed by sinusoidally varying the radius of a circle to add 'bumps' of a certain number to a circle - can be used to examine local and global form perception. Typically developing children and children with an ASD discriminated between circles and RF patterns that are processed either locally (RF24) or globally (RF3).

RESULTS

Children with an ASD required greater shape deformation to identify RF3 shapes compared to typically developing children, consistent with difficulty in global processing in the ventral stream. No group difference was observed for RF24 shapes, suggesting intact local ventral-stream processing.

CONCLUSIONS

These outcomes support the position that a deficit in global visual processing is present in ASDs, consistent with the notion of Weak Central Coherence.

Investigating the functional integrity of the dorsal visual pathway in autism and dyslexia

Numerous reports of elevated global motion thresholds across a variety of neurodevelopmental disorders have prompted researchers to suggest that abnormalities in global motion perception are a result of a general deficiency in the dorsal visual pathway. To test this hypothesis, we assessed the integrity of the dorsal visual pathway at lower subcortical (sensitivity to flicker contrast) and higher cortical (sensitivity to global motion) levels in children with autism, children with dyslexia, and typically developing children, of similar age and ability. While children with autism demonstrated intact lower-level, but impaired higher-level dorsal-stream functioning, children with dyslexia displayed abnormalities at both lower and higher levels of the dorsal visual stream. These findings suggest that these disorders can be dissociated according to the origin of the impairment along the dorsal-stream pathway. Implications for general cross-syndrome accounts are discussed.

Abnormal adaptive face-coding mechanisms in children with autism spectrum disorder

In low-level vision, exquisite sensitivity to variation in luminance is achieved by adaptive mechanisms that adjust neural sensitivity to the prevailing luminance level. In high-level vision, adaptive mechanisms contribute to our remarkable ability to distinguish thousands of similar faces [1]. A clear example of this sort of adaptive coding is the face-identity aftereffect [2, 3, 4, 5], in which adaptation to a particular face biases perception toward the opposite identity. Here we investigated face adaptation in children with autism spectrum disorder (ASD) by asking them to discriminate between two face identities, with and without prior adaptation to opposite-identity faces. The ASD group discriminated the identities with the same precision as did the age- and ability-matched control group, showing that face identification per se was unimpaired. However, children with ASD showed significantly less adaptation than did their typical peers, with the amount of adaptation correlating significantly with current symptomatology, and face aftereffects of children with elevated symptoms only one third those of controls. These results show that although children with ASD can learn a simple discrimination between two identities, adaptive face-coding mechanisms are severely compromised, offering a new explanation for previously reported face-perception difficulties [6, 7, 8] and possibly for some of the core social deficits in ASD [9, 10].