Anna Remington

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.

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.

Lightening the Load: Perceptual Load Impairs Visual Detection in Typical Adults but Not in Autism

Autism spectrum disorder (ASD) research portrays a mixed picture of attentional abilities with demonstrations of enhancements (e.g., superior visual search) and deficits (e.g., higher distractibility). Here we test a potential resolution derived from the Load Theory of Attention (e.g., Lavie, 2005). In Load Theory, distractor processing depends on the perceptual load of the task and as such can only be eliminated under high load that engages full capacity. We hypothesize that ASD involves enhanced perceptual capacity, leading to the superior performance and increased distractor processing previously reported. Using a signal-detection paradigm, we test this directly and demonstrate that, under higher levels of load, perceptual sensitivity was reduced in typical adults but not in adults with ASD. These findings confirm our hypothesis and offer a promising solution to the previous discrepancies by suggesting that increased distractor processing in ASD results not from a filtering deficit but from enhanced perceptual capacity.

Increasing food acceptance in the home setting: a randomized controlled trial of parent-administered taste exposure with incentives

BACKGROUND The use of rewards to encourage children to eat healthily is controversial. However, researcher-led interventions have shown that incentives combined with taste exposure can increase both intake and liking. To date, this has not been tested in the home setting. OBJECTIVES The objectives were to test the hypothesis that parent-administered repeated taste exposures to an initially disliked vegetable combined with reward will increase childrens liking and intake and to compare the effects of tangible and social rewards. DESIGN In this randomized controlled trial, families with children aged 3-4 y (n = 173) were randomly assigned to exposure + tangible reward (sticker), exposure + social reward (praise), or no-treatment control conditions after a pretest assessment in which a target vegetable was selected for each child. In the intervention groups, parents offered their children 12 daily tastes of the vegetable, giving either praise or a sticker for tasting. No specific advice was given to the control group. Assessments of intake and liking of the target vegetable were conducted by researchers immediately after the intervention period and 1 and 3 mo later. RESULTS Children who received exposure + tangible rewards increased their intake (P = 0.001) and liking (P = 0.001) of their target vegetable significantly more than did children in the control group. Differences were maintained at the 3-mo follow-up (intake: P = 0.005; liking: P = 0.001). Increases in intake and liking in the exposure + social reward group were not significantly different from the control group. CONCLUSION The findings of this home-based study support parental use of tangible rewards with repeated taste exposures to improve childrens diets. This trial is registered as ISRCTN42922680.

Seeing the unseen: autism involves reduced susceptibility to inattentional blindness.

OBJECTIVE Attention research in individuals with autism spectrum disorder (ASD) has produced conflicting results. Some findings demonstrate greater distractibility while others suggest superior focused attention. Applying Lavies load theory of attention to account for this discrepancy led us to hypothesize increased perceptual capacity in ASD. Preliminary support for our hypothesis has so far been found for adults with ASD with reaction time (RT) and signal detection sensitivity measures. Here we test the novel prediction we derived from this hypothesis that children with ASD should have lower rates of inattentional blindness than controls. METHOD Twenty-four children with ASD (mean age = 10 years 10 months) and 39 typically developing children (age and IQ matched) took part in the study. We assessed the effects of perceptual load on the rates of inattentional blindness in each group. Participants performing a line discrimination task in either a high load or low load condition were presented with an unexpected extra stimulus on a critical trial. Performance on the line judgment task and rates of detection and stimulus identification were recorded. RESULTS Overall rates of detection and identification were higher in the ASD group than in the controls. Moreover, whereas both detection and identification rates were significantly lower in the high (compared with low) load conditions for the controls, these were unaffected by load in the ASD group. CONCLUSION Reduced inattentional blindness rates under load in ASD suggests higher perceptual capacity is a core feature, present from childhood and leading to superior performance in various measures of perception and attention.

I can see clearly now: the effects of age and perceptual load on inattentional blindness

Attention and awareness are known to be linked (e.g., see Lavie et al., 2014, for a review). However the extent to which this link changes over development is not fully understood. Most research concerning the development of attention has investigated the effects of attention on distraction, visual search and spatial orienting, typically using reaction time measures which cannot directly support conclusions about conscious awareness. Here we used Lavie’s Load Theory of Attention and Cognitive Control to examine the development of attention effects on awareness. According to Load Theory, awareness levels are determined by the availability of attentional capacity. We hypothesized that attentional capacity develops with age, and consequently that awareness rates should increase with development due to the enhanced capacity. Thus we predicted that greater rates of inattentional blindness (IB) would be found at a younger age, and that lower levels of load will be sufficient to exhaust capacity and cause IB in children but not adults. We tested this hypothesis using an IB paradigm with adults and children aged 7–8, 9–10, 11–12 and 13 years old. Participants performed a line-length judgment task (indicating which arm of a cross is longer) and on the last trial were asked to report whether they noticed an unexpected task-irrelevant stimulus (a small square) in the display. Perceptual load was varied by changing the line-length difference (with a smaller difference in the conditions of higher load). The results supported our hypothesis: levels of awareness increased with age, and a moderate increase in the perceptual load of the task led to greater IB for children but not adults. These results extended across both peripheral and central presentations of the task stimuli. Overall, these findings establish the development of capacity for awareness and demonstrate the critical role of the perceptual load in the attended task.

Attentional status of faces for people with autism spectrum disorder

In recent years there has been a growing interest in the role of attention in the processing of social stimuli in individuals with autism spectrum disorders (ASD). Research has demonstrated that, for typical adults, faces have a special status in attention and are processed in an automatic and mandatory fashion even when participants attempt to ignore them. Under conditions of high load in a selective attention task, when irrelevant stimuli are usually not processed, typical adults continue to process distractor faces. Although there is evidence of a lack of attentional bias towards faces in ASD, there has been no direct test of whether faces are processed automatically using the distractor-face paradigm. In the present study 16 typical adults and 16 adults with ASD performed selective attention tasks with face and musical instrument distractors. The results indicated that even when the load of the central task was high, typical adults continued to be distracted by irrelevant face stimuli, whereas individuals with ASD were able to ignore them. In the equivalent non-social task, distractors had no effect at high load for either group. The results suggest that faces are processed in an automatic and mandatory fashion in typical adults but not in adults with ASD.

Brain development and the attention spectrum

Decreased attention span, hyperactivity, distractibility, and impulsivity are sensitive but non-specific brain functions and behavioral patterns. These expressions of altered functioning should be acknowledged as non-specific, rather than trying to fit them into existing diagnoses. These abnormalities should be viewed in terms of underlying developmental processes and not as components of discrete non-overlapping disorders. The tendency to squeeze a group of symptoms into a diagnostic entity has the potential to lead to a non-accurate diagnosis, a less than successful treatment plan, and has the potential to be of little prognostic value (Berger and Nevo, 2011). The developmental approach can provide predictions as to how characteristics associated with attention change over time, and how multiple risk and protective factors influence these temporal changes. It also has the potential to more readily anticipate associated co-morbid features and disorders (Berger and Nevo, 2011; Visser et al., 2014). Attention Deficit Hyperactivity Disorder (ADHD) seems to be considerably more common than other diagnoses among “double-diagnoses” given to children with developmental dysfunctions. Yet the exact prevalence, neurobiological mechanisms, genetic and epigenetic modifications, diagnostic difficulties and treatment methods have not been clearly identified or quantified. During the last years, the number of publications in this field has grown substantially, but, in part, due to the wide range of interested professionals, these studies have been published in a wide range of journals, sometimes missing some of their “target” populations.

Life is much more difficult to manage during periods: Autistic experiences of menstruation

Although menarche and menstruation are perceived to be overwhelmingly negative events for developmentally-disabled women, women’s health issues remain under-researched in autism. Here, we conducted a preliminary investigation of the experiences of post-menarcheal autistic (n = 123) and non-autistic (n = 114) respondents to a brief online survey. Although autistic respondents reported many overlapping issues and experiences with non-autistic respondents, they also highlighted distinct—and sometimes-distressing—issues relating to menstruation, especially a cyclical amplification of autistic-related challenges, including sensory differences and difficulties with regulating emotion and behavior, which had a significant, negative impact on their lives. These initial findings call for systematic research on the potential causes, correlates and consequences of menstrual-related problems in autistic individuals—across the spectrum and the lifespan.

Excluded from school: Autistic students’ experiences of school exclusion and subsequent re-integration into school:

Background and aims All children have the right to receive an education and to be included in school. Yet young people on the autism spectrum, who are already vulnerable to poor health and social outcomes, are at increased risk of school exclusion. The current study sought to understand the key factors surrounding the school exclusion experiences of a group of autistic students with particularly complex needs, and their subsequent re-integration into education. Method We interviewed nine intellectually able students (eight male, one female; M age = 13.3 years), all with a diagnosis of autism and the majority with a history of demand avoidant behaviour. We also interviewed their parents and teaching staff about the students’ past and current school experiences. All students were currently being educated within an ‘Inclusive Learning Hub’, specially designed to re-integrate excluded, autistic students back into school, which was situated within a larger autism special school. Results Young people and their parents gave overwhelmingly negative accounts of the students’ previous school experiences. Children’s perceived unmet needs, as well as inappropriate approaches by previous school staff in dealing with children’s difficulties, were felt to cause decline in children’s mental health and behaviour and, ultimately, led to their exclusion from school. Four key factors for successful reintegration into school were identified, including (i) making substantial adjustments to the physical environment, (ii) promoting strong staff–student relationships, (iii) understanding students’ specific needs, and (iv) targeted efforts towards improving students’ wellbeing. Conclusion The culmination – and escalation – of challenges students experienced in the students’ previous placements could suggest that the educational journey to exclusion from school is an inevitable consequence for at least some autistic children, including those with particularly complex behaviour, as sampled here. Yet, our study encouragingly showed that this was not necessarily the case. All the young people we spoke to reported being happy, safe and secure in their current placement, and re-engaged with school life. Outstanding issues remain, however, with regard to children’s reportedly slow academic progress and difficulties generalising the positive behaviour shown in school across home and community contexts. Implications More remains to be done to ensure that autistic children and young people’s progress at school is also mirrored in other settings. Future research also needs to develop more preventative approaches to avoid exclusion from school, including efforts towards improving education professionals’ knowledge and awareness of autism, and effective ways of responding to these students’ needs.