1. de Marchena A, Miller J. {{« Frank » presentations as a novel research construct and element of diagnostic decision-making in autism spectrum disorder}}. {Autism Res};2016 (Oct 21)
Many individuals with ASD have a distinctive behavioral presentation that is recognizable within moments, a phenomenon we call « frank » ASD. This phenomenon has been discussed informally for decades, perhaps as « classic » ASD; however, there is no unitary « classic » presentation, and classic autism does not seem to correspond to level of functioning. Thus, neither « frank » nor « classic » autism has been delineated or studied as a research construct. To initiate the empirical study of frank ASD, we surveyed 151 clinicians, from a range of disciplines that diagnose ASD, about this phenomenon. Respondents completed a 13-item questionnaire about frank ASD, which was analyzed using a mixed-methods approach. Ninety-seven percentage of respondents were familiar with the phenomenon. Respondents estimated that 40% of the ASD population has a frank presentation. Respondents reported the most highly specific behaviors associated with frank presentations were a general sense of impaired reciprocity, quality of eye contact, atypical vocal prosody, presence of motor mannerisms, and atypical gait or posture. In general, respondents reported detecting frank features rapidly, with the majority forming their impressions within the first ten minutes of interaction or observation. Although unstudied empirically, « frank » presentations of ASD are familiar to diagnosing clinicians, and appear to be based on behaviors both central to ASD diagnostic criteria (e.g., impaired reciprocity), and absent from diagnostic criteria (e.g., atypical gait or posture). We discuss these findings within the context of diagnostic decision-making and behavioral phenotyping of ASD. Autism Res 2016,. (c) 2016 International Society for Autism Research, Wiley Periodicals, Inc.
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2. Ego C, Bonhomme L, Orban de Xivry JJ, Da Fonseca D, Lefevre P, Masson GS, Deruelle C. {{Behavioral characterization of prediction and internal models in adolescents with autistic spectrum disorders}}. {Neuropsychologia};2016 (Oct);91:335-345.
Autism has been considered as a deficit in prediction of the upcoming event or of the sensory consequences of our own movements. To test this hypothesis, we recorded eye movements from high-functioning autistic adolescents and from age-matched controls during a blanking paradigm. In this paradigm, adolescents were instructed to follow a moving target with their eyes even during its transient disappearance. Given the absence of visual information during the blanking period, eye movements during this period are solely controlled on the basis of the prediction of the ongoing target motion. Typical markers of predictive eye movements such as the number and accuracy of predictive saccades and the predictive reacceleration before target reappearance were identical in the two populations. In addition, the synergy of predictive saccades and smooth pursuit observed during the blanking periods, which is a marker for the quality of internal models about target/eye motions, was comparable between these two populations. These results suggest that, in our large population of high-functioning autistic adolescent, both predictive abilities and internal models are left intact in Autism, at least for low-level sensorimotor transformations.
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3. Gokoolparsadh A, Sutton GJ, Charamko A, Green NF, Pardy CJ, Voineagu I. {{Searching for convergent pathways in autism spectrum disorders: insights from human brain transcriptome studies}}. {Cell Mol Life Sci};2016 (Dec);73(23):4517-4530.
Autism spectrum disorder (ASD) is one of the most heritable neuropsychiatric conditions. The complex genetic landscape of the disorder includes both common and rare variants at hundreds of genetic loci. This marked heterogeneity has thus far hampered efforts to develop genetic diagnostic panels and targeted pharmacological therapies. Here, we give an overview of the current literature on the genetic basis of ASD, and review recent human brain transcriptome studies and their role in identifying convergent pathways downstream of the heterogeneous genetic variants. We also discuss emerging evidence on the involvement of non-coding genomic regions and non-coding RNAs in ASD.
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4. Hall A, Finch T, Kolehmainen N, James D. {{Implementing a video-based intervention to empower staff members in an autism care organization: a qualitative study}}. {BMC Health Serv Res};2016 (Oct 21);16(1):608.
BACKGROUND: Implementing good-quality health and social care requires empowerment of staff members within organizations delivering care. Video Interaction Guidance (VIG) is an intervention using positive video feedback to empower staff through reflection on practice. This qualitative study explored the implementation of VIG within an autism care organization in England, from the perspective of staff members undergoing training to deliver VIG. METHODS: Semi-structured interviews were conducted with a purposive sample of 7 participants working within the organization (5 staff undergoing training to deliver VIG; 2 senior managers influencing co-ordination of training). Participants were asked about their views of VIG and its implementation. The topic guide was informed by Normalization Process Theory (NPT). Data were analysed inductively and emerging issues were related to NPT. RESULTS: Five broad themes were identified: (1) participants reported that they and other staff did not understand VIG until they became involved, initially believing it would highlight negative rather than positive practice; (2) enthusiastic feedback from staff who had been involved seemed to encourage other staff to become involved; (3) key implementation challenges included demands of daily work and securing managers’ support; (4) ideas for future practice arising from empowerment through VIG seemed difficult to realise within an organizational culture reportedly unreceptive to creative ideas from staff; (5) individuals’ emotional responses to implementation seemed beyond the reach of NPT, which focused more upon collective processes. CONCLUSIONS: Implementation of VIG may require recognition that it is not a ‘quick fix’. Peer advocacy may be a fruitful implementation strategy. Senior managers may need to experience VIG to develop their understanding so that they can provide appropriate implementation support. NPT may lack specificity to explain how individual agency weaves with collective processes and social systems to embed innovation in routine practice. This exploratory study has provided broad insights into facilitators and barriers to the implementation of an intervention to empower staff within an autism care organization. Further research is needed into similar interventions, including a focus upon staff members’ emotional responses and resources, and how such interventions may relate to the culture of the organization in which implementation occurs.
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5. Powell G, Meredith Z, McMillin R, Freeman TC. {{Bayesian Models of Individual Differences: Combining Autistic Traits and Sensory Thresholds to Predict Motion Perception}}. {Psychol Sci};2016 (Oct 21)
According to Bayesian models, perception and cognition depend on the optimal combination of noisy incoming evidence with prior knowledge of the world. Individual differences in perception should therefore be jointly determined by a person’s sensitivity to incoming evidence and his or her prior expectations. It has been proposed that individuals with autism have flatter prior distributions than do nonautistic individuals, which suggests that prior variance is linked to the degree of autistic traits in the general population. We tested this idea by studying how perceived speed changes during pursuit eye movement and at low contrast. We found that individual differences in these two motion phenomena were predicted by differences in thresholds and autistic traits when combined in a quantitative Bayesian model. Our findings therefore support the flatter-prior hypothesis and suggest that individual differences in prior expectations are more systematic than previously thought. In order to be revealed, however, individual differences in sensitivity must also be taken into account.
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6. Prat CS, Stocco A, Neuhaus E, Kleinhans NM. {{Basal ganglia impairments in autism spectrum disorder are related to abnormal signal gating to prefrontal cortex}}. {Neuropsychologia};2016 (Oct);91:268-281.
Research on the biological basis of autism spectrum disorder has yielded a list of brain abnormalities that are arguably as diverse as the set of behavioral symptoms that characterize the disorder. Among these are patterns of abnormal cortical connectivity and abnormal basal ganglia development. In attempts to integrate the existing literature, the current paper tests the hypothesis that impairments in the basal ganglia’s function to flexibly select and route task-relevant neural signals to the prefrontal cortex underpins patterns of abnormal synchronization between the prefrontal cortex and other cortical processing centers observed in individuals with autism spectrum disorder (ASD). We tested this hypothesis using a Dynamic Causal Modeling analysis of neuroimaging data collected from 16 individuals with ASD (mean age=25.3 years; 6 female) and 17 age- and IQ-matched neurotypical controls (mean age=25.6, 6 female), who performed a Go/No-Go test of executive functioning. Consistent with the hypothesis tested, a random-effects Bayesian model selection procedure determined that a model of network connectivity in which basal ganglia activation modulated connectivity between the prefrontal cortex and other key cortical processing centers best fit the data of both neurotypicals and individuals with ASD. Follow-up analyses suggested that the largest group differences were observed for modulation of connectivity between prefrontal cortex and the sensory input region in the occipital lobe [t(31)=2.03, p=0.025]. Specifically, basal ganglia activation was associated with a small decrease in synchronization between the occipital region and prefrontal cortical regions in controls; however, in individuals with ASD, basal ganglia activation resulted in increased synchronization between the occipital region and the prefrontal cortex. We propose that this increased synchronization may reflect a failure in basal ganglia signal gating mechanisms, resulting in a non-selective copying of signals to prefrontal cortex. Such a failure to prioritize and filter signals to the prefrontal cortex could result in the pervasive impairments in cognitive flexibility and executive functioning that characterize autism spectrum disorder, and may offer a mechanistic explanation of some of the observed abnormalities in patterns of cortical synchronization in ASD.
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7. Tsur E, Friger M, Menashe I. {{The Unique Evolutionary Signature of Genes Associated with Autism Spectrum Disorder}}. {Behav Genet};2016 (Nov);46(6):754-762.
Autism spectrum disorder (ASD) is a common heritable neurodevelopmental disorder, which is characterized by communication and social deficits that reduce the reproductive fitness of individuals with the disorder. Here, we studied the genomic characteristics of 651 ASD genes in a whole-exome sequencing dataset, to search for traces of the evolutionary forces that helped maintain ASD in the human population. We show that ASD genes are ~65 longer and ~20 % less variable than non-ASD genes. The mutational shortage in ASD genes was particularly eminent when considering only deleterious genetic variations, which is a hallmark of negative selection. We further show that these genomic characteristics are unique to ASD genes, as compared with brain-specific genes or with genes of other diseases. Our findings suggest that ASD genes have evolved under complex evolutionary forces, which have left a unique signature that can be used to identify new candidate ASD genes.
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8. Vivanti G, Nuske HJ. {{Autism, attachment, and social learning: Three challenges and a way forward}}. {Behav Brain Res};2016 (Oct 14)
We explore three challenges that Autism Spectrum Disorder (ASD) poses to our understanding of the processes underlying early attachment. First, while caregiver-infant attachment and later social-affiliative behavior share common biobehavioral mechanisms, individuals with ASD are able to form secure attachment relationships, despite reduced social-emotional reciprocity and motivation for social interaction. Therefore, disruptions in social affiliation mechanisms can co-exist with secure caregiver-infant bonding. Second, while early attachment quality is associated with later social outcomes in typical development, interventions targeting caregiver-child interaction in ASD often show positive effects on parental responsivity and attachment quality, but not on child social behavior. Therefore, improvements in parent-child bonding do not necessarily result in improvements in social functioning in ASD. Third, individuals with ASD show normative brain activity and selective social affiliative behaviors in response to people that they know but not to unfamiliar people. We propose a conceptual framework to reformulate and address these three theoretical impasses posed by ASD, arguing that the dissociable pathways of child-parent bonding and social development in ASD are shaped by (1) a dissociation between externally-driven and internally-driven attachment responses and (2) atypical learning dynamics occurring during child-caregiver bonding episodes, which are governed by and influence social-affiliation motives and other operant contingencies.
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9. Yeh E, Weiss LA. {{If genetic variation could talk: What genomic data may teach us about the importance of gene expression regulation in the genetics of autism}}. {Mol Cell Probes};2016 (Oct 14)
Autism spectrum disorder (ASD) has been long known to have substantial genetic etiology. Much research has attempted to identify specific genes contributing to ASD risk with the goal of tying gene function to a molecular pathological explanation for ASD. A unifying molecular pathology would potentially increase understanding of what is going wrong during development, and could lead to diagnostic biomarkers or targeted preventative or therapeutic directions. We review past and current genetic mapping approaches and discuss major results, leading to the hypothesis that global dysregulation of gene or protein expression may be implicated in ASD rather than disturbance of brain-specific functions. If substantiated, this hypothesis might indicate the need for novel experimental and analytical approaches in order to understand this neurodevelopmental disorder, develop biomarkers, or consider treatment approaches.
