Lateralized Response Timing Deficits in Autism

Abstract

Background Procedural learning is an implicit process in which a behavioral response is refined through repeated performance. Neural systems supporting this cognitive process include specific frontostriatal systems responsible for the preparation and timing of planned motor responses. Evaluating performance on procedural learning tasks can provide unique information about neurodevelopmental disorders in which frontostriatal disturbances have been reported, such as autism. Methods Fifty-two individuals with autism and 54 age-, IQ-, and gender-matched healthy individuals performed an oculomotor serial reaction time task and a sensorimotor control task. Results Whereas the rate of procedural learning and the precision of planned motor responses were unimpaired in autism, a lateralized alteration in the ability to time predictive responses was observed. Rightward saccadic responses were speeded in individuals with autism relative to healthy control subjects. Conclusions Speeded rightward predictive saccades suggest atypical functioning of left hemisphere striatal chronometric systems in autism.

A Computational Model for Cerebral Cortical Dysfunction in Autism Spectrum Disorders

“…Our computational results agree with reported ASD saccade abnormalities in human subjects (12-15), although reports are inconsistent (32,33). However, an ASD study showing no saccade abnormalities did find differences in functional imaging that might indicate compensatory mechanisms that helped to equalize saccade performance (33).…”

The nature of brain dysfunction in autism: functional brain imaging studies

“…Similar findings were reported in a study of visually guided saccades, with increased activation of pre-SMA, DLPFC, and dorsomedial thalamus in HFA individuals [11*]. However, these results were attributed to an atypical way of utilizing frontal cortex to initiate simple motor acts resulting from atypical brain development, as procedural learning, an implicit process, was found to be intact in HFA [12]. …”

State space analysis of timing: exploiting task redundancy to reduce sensitivity to timing

“…We propose that the method developed here could be useful for examining coordination in impaired populations. Coordinative or state-dependent timing is thought to depend on the cerebellum (Diedrichsen et al 2007) and basal ganglia (Wu et al 2010), and deficits have been observed in subjects with a wide range of neurological disorders, including adults with Parkinson's disease (Gross et al 2008;Tagliabue et al 2009), Huntington's disease (Klein et al 2010), and cerebellar lesions (McNaughton et al 2004) and children with reading delay autism (D'Cruz et al 2009) and attention-deficit/hyperactivity disorder (Frings et al 2010). Intrinsic timing deficits have even been proposed to be central to the etiology of schizophrenia (Andreasen et al 1998;Andreasen and Pierson 2008).…”