Childhood Executive Function Predicts Later Autistic Features and Adaptive Behavior in Young Autistic People: a 12-Year Prospective Study.

Longitudinal studies of autistic people show that the behavioral features of autism generally endure into adulthood. Yet the prognostic indicators remain far from certain, especially for cognitively able individuals. Here, we test the predictive power of specific cognitive skills, namely theory of mind and executive function, measured in childhood, on young people's autistic features and adaptive behavior 12 years later. Twenty-eight young autistic people (2 female) were seen twice within the space of 12 years. At Time 1 (M = 5 years; 7 months, SD = 11 months), participants were assessed on components of executive function (planning, inhibition and cognitive flexibility) and theory of mind (false-belief understanding). At Time 2, 12 years later (M = 17 years 10 months, SD = 1 year; 2 months), we measured participants' autistic features and adaptive behavior. Only Time 1 executive function skills predicted significant variance in autistic adolescents' autistic features, over and above variance attributable to early age, intellectual ability and theory of mind skills. Furthermore, early EF skills, in addition to early verbal ability and nonverbal ability, predicted significant variance in young people's adaptive behavior at the 12-year follow-up. These long-term longitudinal findings clearly demonstrate that executive function measured in early childhood has prognostic significance in a sample of young autistic people approaching emerging adulthood and underscore their importance as a key target for early intervention and support.

Dissociation of local and global contributions to detection of shape with age.

Radial Frequency (RF) patterns are a useful stimulus for assessing sensitivity to changes in shape. With these patterns it is possible to separate sensitivity to local curvature information from the ability to globally integrate information around the contour. Previous work has demonstrated that young, school-age children are less sensitive to deformation in RF patterns than adults. However, since the efficiency of contour integration was not assessed, age-related differences in performance could arise from either changes in the strength of global pooling of information, the sensitivity to local curvature information, or both. In this study, psychophysical methods were used to reassess changes in sensitivity to RF patterns, separating changes in sensitivity to local curvature information from changes in contour integration strength. Typically developing observers (aged 6-24, N = 104) were tested using a 2-alternative forced-choice discrimination task with either 1, 2 or 3 cycles of sinusoidal modulation in a pattern of fixed RF. Thresholds were lower for older observers but the rate of change, as more modulation cycles were added, was approximately constant across age. The results indicate that changes in sensitivity to RF3 patterns across age are due to changes in local curvature sensitivity and not to the strength of contour integration. (PsycINFO Database Record

Embedded Figures Test Performance in the Broader Autism Phenotype: A Meta-analysis.

People with autism show superior performance to controls on the Embedded Figures Test (EFT). However, studies examining the relationship between autistic-like traits and EFT performance in neurotypical individuals have yielded inconsistent findings. To examine the inconsistency, a meta-analysis was conducted of studies that (a) compared high and low Autism-Spectrum Quotient (AQ) groups, and (b) treated AQ as a continuous variable. Outcomes are consistent with superior visual search forming part of the broader autism phenotype, but in existing literature, this is evident only when comparing extreme groups. Reanalysis of data from previous studies suggests findings are unlikely to be driven by a small number of high scorers. Monte Carlo simulations are used to illustrate the effect of methodological differences on results.

Tolerance for local and global differences in the integration of shape information.

Shape is a critical cue to object identity. In psychophysical studies, radial frequency (RF) patterns, paths deformed from circular by a sinusoidal modulation of radius, have proved valuable stimuli for the demonstration of global integration of local shape information. Models of the mechanism of integration have focused on the periodicity in measures of curvature on the pattern, despite the fact that other properties covary. We show that patterns defined by rectified sinusoidal modulation also exhibit global integration and are indistinguishable from conventional RF patterns at their thresholds for detection, demonstrating some indifference to the modulating function. Further, irregular patterns incorporating four different frequencies of modulation are globally integrated, indicating that uniform periodicity is not critical. Irregular patterns can be handed in the sense that mirror images cannot be superimposed. We show that mirror images of the same irregular pattern could not be discriminated near their thresholds for detection. The same irregular pattern and a pattern with four cycles of a constant frequency of modulation completing 2π radians were, however, perfectly discriminated, demonstrating the existence of discrete representations of these patterns by which they are discriminated. It has previously been shown that RF patterns of different frequencies are perfectly discriminated but that patterns with the same frequency but different numbers of cycles of modulation were not. We conclude that such patterns are identified, near threshold, by the set of angles subtended at the center of the pattern by adjacent points of maximum convex curvature.