Motor demands impact speed of information processing in autism spectrum disorders.

Abstract

Objective The apparent contradiction between preserved or even enhanced perceptual processing speed on inspection time tasks in autism spectrum disorders (ASD) and impaired performance on complex processing speed tasks that require motor output (e.g. Wechsler Processing Speed Index) has not yet been systematically investigated. This study investigates whether adding motor output demands to an inspection time task impairs ASD performance compared to that of typically developing control (TDC) children. Method The performance of children with ASD (n=28; mean FSIQ=115) and TDC (n=25; mean FSIQ=122) children was compared on processing speed tasks with increasing motor demand. Correlations were run between ASD task performance and Autism Diagnostic Observation Schedule (ADOS) Communication scores. Results Performance by the ASD and TDC groups on a simple perceptual processing speed task with minimal motor demand was equivalent, though it diverged (ASD worse than TDC) on two tasks with the same stimuli, but increased motor output demands. ASD performance on the moderate but not the high speeded motor output demand task was negatively correlated with ADOS communication symptoms. Conclusions These data address the apparent contradiction between preserved inspection time in the context of slowed “processing speed” in ASD. They show that processing speed is preserved when motor demands are minimized, but that increased motor output demands interfere with the ability to act on perceptual processing of simple stimuli. Reducing motor demands (e.g. through the use of computers) may increase the capacity of people with ASD to demonstrate good perceptual processing in a variety of educational, vocational and social settings.

Processing Speed is Impaired in Adults with Autism Spectrum Disorder, and Relates to Social Communication Abilities

“…In addition, the inspection time studies included children with ASD (Scheuffgen et al 2000; Wallace et al 2009; Kenworthy et al 2013), or a broad range of ages from adolescence and adulthood (Barbeau et al 2013), whereas the current study focused on adults with ASD. There may be a developmental change or delay (Williams et al 2013) in processing speed in ASD, which could also explain the discrepancy in results.…”

“…A growing number of investigations have provided evidence of significant reductions in processing speed in both children (Oliveras-Rentas et al 2012; Nader et al 2015; Hedvall et al 2013; Mayes and Calhoun 2007; Bavin et al 2016a, b) and in adults with ASD without comorbid ID (Holdnack et al 2011; Faja et al 2009; Eack et al 2013a), and several studies showed relationships between slower processing speed and impaired measures of social cognition (Oliveras-Rentas et al 2012; Lerner et al 2013). However, there are several studies that do not show reduced processing speed in children with ASD (Scheuffgen et al 2000; Wallace et al 2009; Kenworthy et al 2013), and even fewer that examine the presence of this impairment in adulthood.…”

“…Studies have used a variety of methods to measure processing speed: some used standardized tests from measures of intelligence, for example, the Wechsler Intelligence Scales for Children (Oliveras-Rentas et al 2012; Nader et al 2015; Hedvall et al 2013; Mayes and Calhoun 2007) and the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) battery, which is comprised of tests of neuropsychological functioning (Eack et al 2013a), whereas others have used tests of inspection time (i.e. reaction time to identify which of two lines appears to be longer; Scheuffgen et al 2000; Wallace et al 2009; Kenworthy et al 2013), language tests (Bavin et al 2016a, b) or measures confounded with social-cognitive impairment (Faja et al 2009). When standardized tests have been utilized, the majority of studies have showed impaired processing speed (Oliveras-Rentas et al 2012; Nader et al 2015; Hedvall et al 2013; Mayes and Calhoun 2007; Bavin et al 2016a, bb; Holdnack et al 2011; Faja et al 2009; Eack et al 2013a).…”

Altered Dynamics of the fMRI Response to Faces in Individuals with Autism

“…However, normal appearing activation patterns emerged by the second scan, at which point the ASD group attained the same level of activation that was observed by the controls in the first scan. This suggests that the individuals with ASD may engage in slower, inefficient information processing (Bertone et al 2005; Dawson et al 2005), which may have been compounded by the simple motor response included in our paradigm (Kenworthy et al 2013). …”

Developmental Changes in Brain Function Underlying Inhibitory Control in Autism Spectrum Disorders

“…Increased activation in the putamen in the adolescent ASD group may reflect a compensatory process in order to overcome possible delayed development in cortical (i.e., FEF) control in order to generate a successful AS response. There is little fMRI evidence showing activation differences in putamen in ASD, with one study linking reduced activation in putamen with repetitive behavior symptoms and verbal fluency in ASD [Kenworthy et al, 2013]. However, converging lines of research from PET and structural MRI have suggested that the putamen may be a locus of dysfunction in ASD.…”