Autism Spectrum Disorders

Why Studies of Autism Spectrum Disorders Have Failed to Resolve the Theory Theory Versus Simulation Theory Debate

by Meredith Wilkinson

Co-authored with Linden J Ball

Wilkinson, M. R., & Ball, L. J. (forthcoming) Why Studies of Autism Spectrum Disorders Have Failed to Resolve the Theory Theory Versus Simulation Theory Debate, Review of Philosophy and Psychology, 2012, DOI 10.1007/s13164-012-0097-0

Individual differences in visual search: relationship to autistic traits, discrimination thresholds

by Kevin Brooks

Brock, J., Xu, J. Y. & Brooks, K. R. (2011). Individual differences in visual search: relationship to autistic traits, discrimination thresholds. Perception, 40, 739-742.

Enhanced visual search is widely reported in autism. Here we note a similar advantage for university students... more Enhanced visual search is widely reported in autism. Here we note a similar advantage for university students self-reporting higher levels of autism-like traits. Contrary to prevailing theories of autism, performance was not associated with perceptual-discrimination thresholds for the same stimuli, but was associated with inspection-time threshold--a measure of speed of perceptual processing. Enhanced visual search in autism may, therefore, at least partially be explained by faster speed of processing.

Functional connectivity for an "Island of sparing" in autism spectrum disorder: An fMRI study of visual search

by Patricia Shih

Keehn B., Shih P., Brenner L.A., Townsend J., Müller R.A. (2012). Functional connectivity for an "Island of sparing" in autism spectrum disorder: An fMRI study of visual search. Human Brain Mapping. doi:10.1002/hbm.22084

Although autism is usually characterized with respect to sociocommunicative impairments, visual search is known as a... more Although autism is usually characterized with respect to sociocommunicative impairments, visual search is known as a domain of relative performance strength in this disorder. This study used functional MRI during visual search in children with autism spectrum disorder (n = 19; mean age = 13;10) and matched typically developing children (n = 19; mean age = 14;0). We selected regions of interest within two attentional networks known to play a crucial role in visual search processes, such as goal-directed selective attention, filtering of irrelevant distractors, and detection of behaviorally-relevant information, and examined activation and connectivity within and between these attentional networks. Additionally, based on prior research suggesting links between visual search abilities and autism symptomatology, we tested for correlations between sociocommunicative impairments and behavioral and neural indices of search. Contrary to many previous functional connectivity magnetic resonance imaging studies of autism that reported functional underconnectivity for task domains of weakness, we found atypically increased connectivity within and between attentional networks in autism. Additionally, we found increased functional connectivity for occipital regions, both locally and for long-distance connections with frontal regions. Both behavioral and neural indices of search were correlated with sociocommunicative impairment in children with autism. This association suggests that strengths in nonsocial visuospatial processing may be related to the development of core autistic sociocommunicative impairments.

The Tyranny of Neuronormativity: Questioning Neurotypical Privilege in Communication

by Marlo Goldstein Hode

Working Memory In Children With Autism and With Moderate Learning Difficulties

by Lucy Henry

Russell, J., Jarrold, C. & Henry, L. (1996). Working memory in children with autism and with moderate learning difficulties. Journal of Child Psychology and Psychiatry, 37, 673-686.

Eye-Witness Memory and Suggestibility In Children With Asperger Syndrome

by Lucy Henry

McCrory, E., Henry, L.A. & Happé, F. (2007). Eyewitness memory and suggestibility in children with Asperger syndrome. Journal of Child Psychology and Psychiatry, 48, 482-489.

Background: Individuals with autism spectrum disorders (ASD) present with a particular profile of memory deficits,... more Background: Individuals with autism spectrum disorders (ASD) present with a particular profile of memory deficits, executive dysfunction and impaired social interaction that may raise concerns about their recall and reliability in forensic and legal contexts. Extant studies of memory shed limited light on this issue as they involved either laboratory-based tasks or protocols that varied between participants.
Method: The current study used a live classroom event to investigate eye-witness recall and suggestibility in children with Asperger syndrome (AS group; N = 24) and typically developing children (TD group; N = 27). All participants were aged between 11 and 14 years and were interviewed using a structured protocol. Two measures of executive functioning were also administered.
Results: The AS group were found to be no more suggestible and no less accurate than their peers. However, free recall elicited less information, including gist, in the AS group. TD, but not AS, participants tended to focus on the socially salient aspects of the scene in their free recall. Both general and specific questioning elicited similar numbers of new details in both groups. Significant correlations were found between memory recall and executive functioning performance in the AS group only.
Conclusions: The present study indicates that children with AS can act as reliable witnesses but they may be more reliant on questioning to facilitate recall. Our findings also provide evidence for poor gist memory. It is speculated that such differences stem from weak central coherence and lead to a reliance on generic cognitive processes, such as executive functions, during recall. Future studies are required to investigate possible differences in compliance, rates of forgetting and false memory.

Keywords: Asperger syndrome, autistic disorder, memory, eye-witness, suggestibility, executive function.

Effect of alexithymia on the perception of emotional vocalisation

by Rory Allen

This is a pre-publication version of a paper published in Psychological Medicine in 2012. The official online version of the paper is available from the publishers at the URL: http://www.ncbi.nlm.nih.gov/pubmed/22475181
http://www.ncbi.nlm.nih.gov/pubmed/22475181

Abstract. Results from a number of recent studies suggest that alexithymia, a disorder characterized by impairments in... more Abstract. Results from a number of recent studies suggest that alexithymia, a disorder characterized by impairments in understanding personal experiences of emotion, is frequently co-morbid with Autism Spectrum Disorder (ASD). However, the extent that alexithymia is associated with primary deficits in recognizing external emotional cues, characteristic in ASD, has yet to be determined. Twenty high-functioning adults with ASD and age and intelligence matched typical controls, categorized vocal and verbal expressions of emotion and completed an alexithymia assessment. The results showed that emotion recognition in the ASD group was influenced by the psychoacoustic complexity of the presented stimuli as well as by the severity of alexithymia. Strong associations between alexithymia and emotion recognition scores were also noted for the control group, and this suggests a potential explanation for variability in emotion recognition in non-clinical populations.

The Systems Theory of Autistogenesis : Putting the Pieces Together

by J Patrick Malone

The systems theory of autistogenesis accounts for genetic and environmental predisposing factors for pervasive... more The systems theory of autistogenesis accounts for genetic and environmental predisposing factors for pervasive developmental disorders. During development, regions of the brain myelinate differentially, even while neuroinflammatory events induce neurological damage. Incorrect dietary ratios of docosahexaenoic acid (DHA) to arachidonic acid (AA) promote developmental aberration characteristic of autism spectrum disorders (ASD), and commercial infant formulae possesses DHA/AA ratios unsuitable for normal brain development in those predisposed. The aromatase gene regulates DHA/AA metabolism and represents a potential biomarker for ASD. Aromatase converts testosterone to estradiol. Estradiol is neuroprotective and a modulator of oxytocin receptors deficient in autism. Neuroprotective DHA is not well synthesized in males and is regulated by estradiol. Therefore, converging evidence indicates that any disturbance to the autistogenic system linking environment to neurobiology and genetics is capable of inducing developmental disorders with gender disparity.

Eye Movement Sequences during Simple versus Complex Information Processing of Scenes in Autism Spectrum Disorder

by Sheena Au-Yeung

Authors: Sheena K. Au-Yeung, Valerie Benson, Monica Castelhano, and Keith Rayner

Published in "Autism Research and Treatment", 2011

doi:10.1155/2011/657383

Minshew and Goldstein (1998) postulated that autism spectrum disorder (ASD) is a disorder of complex information... more Minshew and Goldstein (1998) postulated that autism spectrum disorder (ASD) is a disorder of complex information processing. The current study was designed to investigate this hypothesis. Participants with and without ASD completed two scene perception tasks: a simple “spot the difference” task, where they had to say which one of a pair of pictures had a detail missing, and a complex “which one's weird” task, where they had to decide which one of a pair of pictures looks “weird”. Participants with ASD did not differ from TD participants in their ability to accurately identify the target picture in both tasks. However, analysis of the eye movement sequences showed that participants with ASD viewed scenes differently from normal controls exclusively for the complex task. This difference in eye movement patterns, and the method used to examine different patterns, adds to the knowledge base regarding eye movements and ASD. Our results are in accordance with Minshew and Goldstein's theory that complex, but not simple, information processing is impaired in ASD.

Recent advances in MeCP2 structure and function

by Kristopher Hite

DNA binding restricts the intrinsic conformational flexibility of methyl CpG binding protein 2 (MeCP2)

by Kristopher Hite

Zespół Aspergera, nauki ścisłe i kultura nerdów

by Piotr Migdal

Hudson_Nijboer_Jellema_2012

by Matthew Hudson

The Role of Oxytocin, Vasopressin, and D-Cycloserine in Remediating Social Behavior in Rats with Amygdala Lesions

by Kristina Scanlan

Published in the Journal of Student Research

Autism is a common neurodevelopmental disorder that affects communication and social behavior. To reduce the social... more Autism is a common neurodevelopmental disorder that affects communication and social behavior. To reduce the social deficits characteristic of autism, the compounds oxytocin, arginine vasopressin, D-cycloserine, and D-cycloserine + oxytocin were explored as therapeutic agents. Twenty-one Long Evans Hooded rats underwent a bilateral amygdala lesion, which reduced the time of social interactions between the pairs of animals. Upon administration of D-cycloserine, the social deficits induced by the lesions were significantly reversed in both sexes. In addition, it was observed that the efficacy of the treatments was affected by the sex of the subjects. Male rats had the largest increase in social behavior when given D-cycloserine. However, female rats experienced the largest reduction in social impairment when administered oxytocin. Thus, sexually dimorphic treatments should be further investigated for individuals with autism spectrum disorders.
Keywords: oxytocin, vasopressin, D-cycloserine, amygdala, sexual dimorphism

Diagnosable: Mothering at the Threshold of Disability

by Julia Miele Rodas

in Disability and Mothering. Disability and Mothering: Liminal Spaces of Embodied Knowledge. Eds. Cynthia Lewiecki-Wilson and Jen Cellio. Syracuse Univ Press, 2011. Print.

This is an essay about a hotly contested issue in the experience and theory of disability: The question of how to... more This is an essay about a hotly contested issue in the experience and theory of disability: The question of how to locate, talk about, and live with an ambiguous disability identity. Because many disabilities are not immediately evident, because many are progressive or create erratic episodes of impairment, and because cultural and political considerations factor largely into competing definitions of disability historically and globally, scholars and activists have been keenly attentive to how individuals locate themselves in relation to disability. While I identify with disability identity in broader terms, however, I do not want to reduce myself to a label for the social convenience of my peers. And, while my desire for medical definition offers the possibility of affirmation, it also facilitates a greater threat. For the labeling of disability effectively generates exclusion and misunderstanding, leading to the dismissal of the person as an individual; bias abounds. There are strong competing concerns in this liminal space: unless we self-identify, we participate in the rampant oppression of and discrimination against disability, but I feel stronger and better acting out my resistance from the margin of what Tobin Siebers has called the disability “masquerade” than I do by potentially acting collectively with friends and colleagues who self-identify. My desire to remain in the indefinite, occupying the “diagnosable” space, is not so much an unwillingness to stand up politically as it is a desire to challenge the disciplinary and diagnostic boundaries of the conventional order. For my own sake, certainly, for the sake of my children, but also for the sake of my colleagues, my neighbors, and my fellow parents, I embrace this undisciplined space, rejecting the confinement of diagnosis and thus choosing to challenge the narrowing definition of human “normalcy.”

Differential habituation to repeated sounds in infants at high risk for autism

by Przemyslaw Tomalski

Guiraud JA, Kushnerenko E, Tomalski P, Davies K, Ribeiro H, Johnson MH; BASIS Team, Neuroreport, 22(16):845-849.

It has been suggested that poor habituation to stimuli might explain atypical sensory behaviours in autism. We... more It has been suggested that poor habituation to stimuli might explain atypical sensory behaviours in autism. We investigated habituation to repeated sounds using an oddball paradigm in 9-month-old infants with an older sibling with autism and hence at high risk for developing autism. Auditory-evoked responses to repeated sounds in control infants (at low risk of developing autism) decreased over time, demonstrating habituation, and their responses to deviant sounds were larger than responses to standard sounds, indicating discrimination. In contrast, neural responses in infants at high risk showed less habituation and a reduced sensitivity to changes in frequency. Reduced sensory habituation may be present at a younger age than the emergence of autistic behaviour in some individuals, and we propose that this could play a role in the over responsiveness to some stimuli and undersensitivity to others observed in autism.

Atypical audiovisual speech integration in infants at risk for autism

by Przemyslaw Tomalski

Guidau J., Tomalski P., Kushnerenko E., Ribeiro H., Davies K., Charman T., Elsabbagh M., Johnson M.H., and the BASIS Team, PLOS One, in press

The language difficulties often seen in individuals with autism might stem from an inability to integrate audiovisual... more The language difficulties often seen in individuals with autism might stem from an inability to integrate audiovisual information, a skill important for language development. We investigated whether 9-month-old siblings of older children with autism, who are at an increased risk of developing autism, are able to integrate audiovisual speech cues. We used an eye-tracker to record where infants looked when shown a screen displaying two faces of the same model, where one face is articulating /ba/ and the other /ga/, with one face congruent with the syllable sound being presented simultaneously, the other face incongruent. This method was successful in showing that infants at low risk can integrate audiovisual speech: they looked for the same amount of time at the mouths in both the fusible visual /ga/ - audio /ba/ and the congruent visual /ba/ - audio /ba/ displays, indicating that the auditory and visual streams fuse into a McGurk-type of syllabic percept in the incongruent condition. It also showed that low risk infants could perceive a mismatch between auditory and visual cues: they looked longer at the mouth in the mismatched, non-fusible visual /ba/ - audio /ga/ display compared with the congruent visual /ga/ - audio /ga/ display, demonstrating that they perceive an uncommon, and therefore interesting, speech-like percept when looking at the incongruent mouth (2-way repeated ANOVA: congruent/incongruent displays: F(1,19) = 4.450, p = 0.048, displays x fusion/mismatch condition interaction: F(1,19) = 9.382, p = 0.006). In contrast, the looking behaviour of infants at high-risk did not differ according to the type of display, suggesting difficulties in matching auditory and visual information (2-way repeated ANOVA: displays: F(1,32) = 1.501, p = 0.229, displays x condition interaction: F(1,32) = 0.607, p = 0.442). In some cases this reduced ability might lead to the poor communication skills characteristic of autism.

Affective-motivational brain responses to direct gaze in children with autism spectrum disorder

by Marc Coutanche

Kylliäinen, A., Wallace, S., Coutanche, M.N., Leppänen, J.M., Cusack, J., Bailey, A.J., & Hietanen, J.K. (2012) - Journal of Child Psychology and Psychiatry

Background:  It is unclear why children with autism spectrum disorders (ASD) tend to be inattentive to, or even avoid... more Background:  It is unclear why children with autism spectrum disorders (ASD) tend to be inattentive to, or even avoid eye contact. The goal of this study was to investigate affective–motivational brain responses to direct gaze in children with ASD. To this end, we combined two measurements: skin conductance responses (SCR), a robust arousal measure, and asymmetry in frontal electroencephalography (EEG) activity which is associated with motivational approach and avoidance tendencies. We also explored whether degree of eye openness and face familiarity modulated these responses.

Methods:  Skin conductance responses and frontal EEG activity were recorded from 14 children with ASD and 15 typically developing children whilst they looked at familiar and unfamiliar faces with eyes shut, normally open or wide-open. Stimuli were presented in such a way that they appeared to be looming towards the children.

Results:  In typically developing children, there were no significant differences in SCRs between the different eye conditions, whereas in the ASD group the SCRs were attenuated to faces with closed eyes and increased as a function of the degree of eye openness. In both groups, familiar faces elicited marginally greater SCRs than unfamiliar faces. In typically developing children, normally open eyes elicited greater relative left-sided frontal EEG activity (associated with motivational approach) than shut eyes and wide-open eyes. In the ASD group, there were no significant differences between the gaze conditions in frontal EEG activity.

Conclusions:  Collectively, the results replicate previous finding in showing atypical modulation of arousal in response to direct gaze in children with ASD but do not support the assumption that this response is associated with an avoidant motivational tendency. Instead, children with ASD may lack normative approach-related motivational response to eye contact.

Family Therapy and Autism: a personal construct approach (2000)

by Harry Procter

In Powell, S. (Ed.) Helping children with autism to learn. David Fulton: London

An affordable compact humanoid robot for autism spectrum disorder interventions in children

by Gregory Fischer