Browsing by Author "Hamilton, Katie"

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    Effortful Control, Attention and Executive Functioning in the Context of Autism Spectrum Disorder
    (2019) Page, Teneille; Malcolm-Smith, Susan; Hamilton, Katie
    Autism Spectrum Disorder (ASD) involves a broad presentation of symptoms classified along continuum of severity, with core deficits in Social Affect and Restricted, Repetitive Behaviours required for formal diagnosis (American Psychiatric Association, 2013; Lauritsen, 2013). The development of particular cognitive, behavioural and interpersonal difficulties seen in ASD is of great interest. Temperament offers particular value given that it influences the development of social behaviours, emotionality and self-regulation (Shiner et al., 2012). The self-regulatory temperament factor, effortful control, is known to be diminished in ASD (Garon et al., 2009, 2016) and is theorised to be related to attention and executive functioning (Rothbart & Rueda, 2005). This link is of particular interest, given that attention and executive function deficits are prominent in ASD (Craig et al., 2016; Lai et al., 2017; Sanders, Johnson, Garavan, Gill, & Gallagher, 2008). To date, however, a thorough literature search failed to yield a study which has investigated whether effortful control,attention and executive functioning are concurrently associated with ASD symptomatology.Moreover, the relationship between effortful control, attention and executive functioning is not as unambiguous as previously theorised in typical development, with little investigation into these relationships in ASD. To elucidate the association effortful control, attention and executive functioning have with ASD symptomatology, the relationship between effortful control and these cognitive variable needs to be better established empirically. Therefore the current investigation’s aims were twofold. Study One investigated the relationship of effortful control with attention and executive functions in neurotypical and ASD samples. Study Two explored the association between effortful control, attention, executive functions and core ASD deficits (i.e. Social Affect and Restricted, Repetitive Behaviours). A sample of 38 ASD and 38 neurotypical boys (aggregate-matched on key demographic factors), aged 6 - 15, and their primary caregivers were recruited. Study One considered both groups (n=76) and featured both quasi-experimental and relational investigations. Study Two focused only on the ASD sample (n=38) and used a purely relational design. Neurocognitive measures were used to assess two attention domains (i.e. attention span and sustained attention), and three executive functions (i.e. working memory, inhibition and switching). Effortful control was measured using a parent-report questionnaire and ASD core deficits were examined using the Autism Diagnostic Observation Schedule, Second edition (ADOS-2; Lord, Luyster, Gotham, & Guthrie, 2012). Results of Study One revealed effortful control was a significant predictor of attention span, working memory and inhibition, with ASD participants performing significantly more poorly on these cognitive domains and rated significantly more poorly on effortful control. Study Two’s results indicated that Social Affect was significantly correlated with inhibition and the interaction effect between effortful control and working memory. Furthermore, only effortful control, attention span and their interaction effect were significantly associated with Restricted Repetitive Behaviours. Specifically, effortful control was found to moderate this relationship. At high levels of effortful control, increased attention span was associated with less Restricted, Repetitive Behaviours. These findings may aid efforts to establish a predictive model for ASD core deficits on the basis of temperament and cognitive difficulties. Keywords: Autism Spectrum Disorder (ASD), Effortful Control, Attention, Executive Functions, Social Affect, Restricted Repetitive Behaviours
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    Empathy in autism spectrum disorder: Predictions from child/adolescent temperament, parenting styles, and parenting stress
    (2019) Ross, Toni Carmen Faith; Malcolm-Smith, Susan; Hamilton, Katie
    Individuals with autism spectrum disorder (ASD) exhibit definitional impairments in social relatedness; a phenomenon that can be explained, in part, by their deficits in empathy. Despite the extent of these deficits, relatively little is known about which factors promote or impede empathic functioning within this group. To date, studies of neurotypical children and adolescents suggest the explanatory power of temperament, parenting style, and parenting stress; associations which have yet to be adequately explored with ASD. Thus, the overarching aim of this investigation was to test whether the aforementioned intra- and interindividual features would predict empathy amongst children and adolescents with ASD. To account for some of the heterogeneity in ASD, two groups of parent-child dyads were recruited: one comprising male children and adolescents with intact receptive and expressive language (n = 40, M = 7.68 years); the other, males with little to no language use in either domain (n = 40, M = 9.09 years). A third group of parent-child pairs comprising male neurotypical children and adolescents with age-appropriate language functioning was included as a comparison sample (n = 40, M = 9.53 years). Parents completed wellestablished questionnaires pertaining to child/adolescent temperament and empathy, as well as parenting style and parenting stress, primarily via telephonic interviews. Results showed that temperamental regulation and negative affectivity were linked to empathy within the neurotypical group in positive and inverse directions, respectively. Only regulatory processes were positively associated with empathy within the non-verbal ASD group, whilst only negative affectivity was inversely associated to empathy within the verbal ASD group. Further, warm, responsive, autonomy-promoting parenting was positively associated with empathy within the neurotypical group, whilst punitive and lax parenting were inversely associated with empathy. Positive forms of parenting were also found to predict empathy within both ASD groups – though somewhat less so within the verbal ASD group. Perhaps a consequence of the severity of their empathic deficits, lax and permissive parenting techniques were not tied to empathy within the ASD groups. Finally, parenting stress was inversely linked to empathy within the non-verbal ASD and neurotypical groups only. Results highlight that findings obtained within neurotypical samples cannot always be extrapolated to ASD. Results further underscore the need for ASD interventions to adopt a family systems perspective, teaching parents how to perceive and respond to their children in adaptive ways.
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    An exploration of the relationship between autism spectrum disorders, theory of mind and the serotonin transporter promoter length polymorphism
    (2014) Hamilton, Katie; Malcolm-Smith, Susan
    Autism Spectrum Disorder (ASD) is a highly heritable prevalent pervasive developmental disorder. All cases have deficits in social communication and interaction and in restricted and repetitive behaviours and interests. The mechanisms underlying different clinical presentations remain elusive. Deficits in Theory of Mind (ToM), the ability to understand that others have mental states independent of one's own, have been suggested as a possibly underlying the socia l deficits in ASD. The serotonin transporter promoter length polymorphism (5 - HTTLPR) has been implicated in ASD, and as serotonin is implicated in social functioning more generally, it is possible that 5 - HTTLPR could underlie social functioning in ASD. As such, ToM and 5 - HTTLPR have been implicated in ASD, and specifically as underlying the social deficits typical of this disorder. This protocol assessed core ASD symptoms (i.e. deficits in social communication and interaction, and impairment in restricted and repetitive behaviours and interests) in 69 children with ASD between the ages of 7 and 14 years. The Autism Social Skills Profile, Social Communication Questionnaire, and Repetitive Behavior Scale - Revised assessed these symptoms. 5 - HTTLPR genotypes were established for 55 of these children. ToM was comprehensively assessed in 57 of the children using the University of Cape Town Autism Research Group's Theory of Mind Battery. This protocol is the first is a series of studies assessing the biological bases for social deficits in ASD. One of the main aims was to pilot the use of ASD scales in a local sample. The preliminary analyses assessed the performance of these scales. This data was also used to assess whether the new DSM - 5's merging of social communication and social interaction into a single domain was supported. Study One then assessed for possible relationships between 5 - HTTLPR and cores ASD symptoms, and hypothesised that the 5 - HTTLPR genotype with the most reduced serotonergic transmission woul d relate to increased deficits in social communication and interaction. Study Two explored possible relationships between core ASD symptoms and ToM, and between 5 - HTTLPR and ToM. It was expected that impairment in social communication and interaction would correlation with reduced ToM ability, and that ToM would be most impaired in children with the genotype with the most reduced serotonergic transmission. Preliminary analyses found the scales did not perform well in a local sample. This was likely due to cultural, socio - economic, and educational factors. The bluntness of the scales 13 and broad nature of ASD characteristics likely also contributed. The DSM - 5's diagnostic criteria were supported. Study One and Study Two found no relationships between core ASD symptoms, ToM, and 5 - HTTLPR. Core ASD symptoms were assessed very broadly and it was not possible to establish clear phenotypes for the participants, which likely undermined analyses. At most this protocol showed that broad assessment of core ASD symptoms is not specific enough to reveal relationships to underlying mechanisms, and that ToM and 5 - HTTLPR are not implicated when board measures are used. We emphasise the need for better measures in ASD. We also believe the serotonin system needs to be investigated beyond 5 - HTTLPR in ASD