Developmental course of autistic social impairment in males

BACKGROUND: Recent research has suggested that autistic social impairment (ASI) is continuously distributed in nature, and that subtle autistic-like social impairments aggregate in the family members of children with pervasive developmental disorders (PDDs). This study examined the longitudinal course of quantitatively-characterized ASI in 3 to 18 year old boys with and without PDD. METHODS: We obtained assessments of 95 epidemiologically ascertained male-male twin pairs and a clinical sample of 95 affected children using the Social Responsiveness Scale (SRS), at two time points, spaced 1–5 years apart. Longitudinal course was examined as a function of age, familial loading for PDD, and autistic severity at baseline. RESULTS: Inter-individual variation in SRS scores was highly preserved over time, with test-retest correlation of 0.90 for the entire sample. SRS scores exhibited modest general improvement over the study period; individual trajectories varied as a function of severity at baseline and were highly familial. CONCLUSION: Quantitative measurements of ASI reflect heritable trait-like characteristics. Such measurements can serve as reliable indices of phenotypic severity for genetic and neurobiologic studies, and have potential utility for ascertaining incremental response to intervention

Visual Processing: Heart Rate Differences Between Low and High Reading Ability Adults

Heart rate (HR) deceleration has been found to be associated with the encoding of visual information, and HR acceleration has been associated with the cognitive activity of previously learned information. This experiment examined differences in the visual processing of letters in high and low ability readers using HR as a dependent measure. Seventy-eight participants were classified as High Ability (HA) or Low Ability (LA) readers based upon comprehension scores on the Nelson Denny Reading Test. Participants were tested in one of two conditions: letter matching or perceptual processing. Participants in both conditions were tested using 1 of 2 variations of an oddball task. The letter matching (LM) condition was presented with odd-ball presentations of the same or different lowercase letter. The perceptual processing (PP) condition was presented with oddball presentations of the same or different fragmented letters. Analyses revealed consistent significant differences in HR for the reading ability conditions and a condition by stimulus presentation interaction. In the LM condition, HA readers consistently displayed HR deceleration whereas the LA readers displayed a reliable HR acceleration during the odd-ball letter identification tasks regardless if the letters were \u27same\u27 or \u27different\u27. In the PP condition the odd-ball presentations for the \u27same\u27 letter on the oddball presentations both the HA and LA readers showed a decrease in HR whereas for the \u27different\u27 letter odd-ball presentations only the LA readers displayed a decrease in HR. The differences in direction of HR and the magnitude of HR change are argued to represent differences in the type attentional processes used in letter identification and amount of effort allocated for the specific attentional processes. The results are discussed in terms of the Lacey-Lacey intake-rejection hypothesis and Jennings limited capacity hypothesis

Timing of the Diagnosis of Autism in African American Children

ObjectivesAfrican American (AA) children affected by autism spectrum disorder (ASD) experience delays in diagnosis and obstacles to service access, as well as a disproportionate burden of intellectual disability (ID) as documented in surveillance data recently published by the US Centers for Disease Control and Prevention. Our objective in this study was to analyze data from the largest-available repository of diagnostic and phenotypic information on AA children with ASD, and to explore the wide variation in outcome within the cohort as a function of sociodemographic risk and specific obstacles to service access for the purpose of informing a national approach to resolution of these disparities.MethodsParents of 584 AA children with autism consecutively enrolled in the Autism Genetic Resource Exchange across 4 US data collection sites completed event history calendar interviews of the diagnostic odysseys for their children with ASD. These data were examined in relation to developmental outcomes of the children with autism and their unaffected siblings.ResultsThe average age of ASD diagnosis was 64.9 months (±49.6), on average 42.3 months (±45.1) after parents' first concerns about their children's development. The relationship between timing of diagnosis and ASD severity was complex, and ID comorbidity was not predicted in a straightforward manner by familial factors associated with cognitive variation in the general population.ConclusionsThese findings document significant opportunity to expedite diagnosis, the need to further understand causes of ID comorbidity, and the necessity to identify effective approaches to the resolution of disparities in severity-of-outcome for AA children with autism