The Functional Neuroanatomy of Spatial Attention in Autism Spectrum Disorder

Department of Psychiatry, University of California, San Diego, La Jolla 92093-0959, USA.
Developmental Neuropsychology (Impact Factor: 2.24). 02/2005; 27(3):425-58. DOI: 10.1207/s15326942dn2703_7
Source: PubMed


This study investigated the functional neuroanatomical correlates of spatial attention impairments in autism spectrum disorders (ASD) using an event-related functional magnetic resonance imaging (FMRI) design. Eight ASD participants and 8 normal comparison (NC) participants were tested with a task that required stimulus discrimination following a spatial cue that preceded target presentation by 100 msec (short interstimulus interval [ISI]) or 800 msec (long ISI). The ASD group showed significant behavioral spatial attention impairment in the short ISI condition. The FMRI results showed a reduction in activity within frontal, parietal, and occipital regions in ASD relative to the NC group, most notably within the inferior parietal lobule. ASD behavioral performance improved in the long ISI condition but was still impaired relative to the NC group. ASD FMRI activity in the long ISI condition suggested that the rudimentary framework of normal attention networks were engaged in ASD including bilateral activation within the frontal, parietal, and occipital lobes. Notable activation increases were observed in the superior parietal lobule and extrastriate cortex. No reliable activation was observed in the posterior cerebellar vermis in ASD participants during either long or short ISI conditions. In addition, no frontal activation during short ISI and severely reduced frontal activation during long ISI was observed in the ASD group. Taken together, these findings suggest a dysfunctional cerebello-frontal spatial attention system in ASD. The pattern of findings suggests that ASD is associated with a profound deficit in automatic spatial attention abilities and abnormal voluntary spatial attention abilities. This article also describes a method for reducing the contribution of physical eye movements to the blood-oxygenation level dependent activity in studies of ASD.

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Available from: Frank Haist, Dec 12, 2014
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    • "Collectively, these findings suggest that Crus I may facilitate a range of pSTS functions relevant to social perception. Given evidence of cellular (Bailey et al., 1998; Kemper and Bauman, 2002; Ritvo et al., 1986; Vargas et al., 2005; Whitney et al., 2009), molecular (Fatemi et al., 2001; Lee et al., 2002; Purcell et al., 2001; Sajdel-Sulkowska et al., 2009; Yip et al., 2009), and functional (Allen et al., 2004; Allen and Courchesne, 2003; Mostofsky et al., 2009; Haist et al., 2005) cerebellar abnormalities in ASD, coupled with evidence of disruptions to pSTS, we hypothesized that atypical connectivity between Crus I and right pSTS would predict social perceptual deficits in ASD. "
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    ABSTRACT: Posterior superior temporal sulcus (pSTS) is specialized for interpreting perceived human actions, and disruptions to its function occur in autism spectrum disorder (ASD). Here we consider the role of Crus I of neocerebellum in supporting pSTS function. Research has associated Crus I activity with imitation and biological motion perception, and neocerebellum is theorized to coordinate activity among cerebral sites more generally. Moreover, cerebellar abnormalities have been associated with ASD. We hypothesized that disordered Crus I–pSTS interactions could predict social deficits in ASD. 15 high functioning adolescents with ASD and 15 same-age comparison youth participated in an fMRI imitation paradigm; ratings of mentalizing ability were collected via parent report. We predicted that stronger Crus I–pSTS interactions would be associated with better mentalizing ability. Consistent with these hypotheses, stronger psychophysiological interactions between Crus I and right pSTS were associated with greater mentalizing ability among adolescents with ASD. Whole-brain analyses also indicated that typically developing youth recruited right inferior frontal gyrus, left pSTS, medial occipital regions, and precuneus more strongly during imitation than did youth with ASD. Overall, these results indicate that variability in neocerebellar interactions with key cortical social brain sites may help explain individual differences in social perceptual outcomes in ASD.
    Full-text · Article · Oct 2014 · Developmental Cognitive Neuroscience
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    • "curacy - based attention effect . Without comparing the RT cueing effects between groups , it is impossible to make a fair comparison of the accuracy - based cuing effects . A previous fMRI study reported weaker modulation of performance accuracy with cue validity in the ASD group with no group differences or group · attention interactions in RT ( Haist et al . , 2005 ) . However , eye movements were not explicitly monitored during the task . Instead , the authors inferred eye movements from the fMRI responses in regions of interest placed over the eyes of the participants . The inferred eye move - ments differed between groups , and differences in eye position during the presentation of the precues "
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    ABSTRACT: Deficits or atypicalities in attention have been reported in individuals with autism spectrum disorder (ASD), yet no consensus on the nature of these deficits has emerged. We conducted three experiments that paired a peripheral precue with a covert discrimination task, using protocols for which the effects of covert exogenous spatial attention on early vision have been well established in typically developing populations. Experiment 1 assessed changes in contrast sensitivity, using orientation discrimination of a contrast-defined grating; Experiment 2 evaluated the reduction of crowding in the visual periphery, using discrimination of a letter-like figure with flanking stimuli at variable distances; and Experiment 3 assessed improvements in visual search, using discrimination of the same letter-like figure with a variable number of distractor elements. In all three experiments, we found that exogenous attention modulated visual discriminability in a group of high-functioning adults with ASD and that it did so in the same way and to the same extent as in a matched control group. We found no evidence to support the hypothesis that deficits in exogenous spatial attention underlie the emergence of core ASD symptomatology.
    Full-text · Article · Dec 2013 · Journal of Vision
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    • "During eye movements, the typically-developing (TD) group activated the oculomotor vermis, whereas the ASD group activated Crus I (Haist et al., 2005), suggesting that the ASD group was not using typical eye-movement regions of the cerebellum but instead utilized association cerebro-cerebellar loops. While not all studies find cerebellar differences during face processing (e.g., Corbett et al., 2009; Schulte-Ruther et al., 2011), others report differences particularly during direct gaze processing (Pitskel et al., 2011). "
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    ABSTRACT: The cerebellum has been long known for its importance in motor learning and coordination. Recently, anatomical, clinical, and neuroimaging studies strongly suggest that the cerebellum supports cognitive functions, including language and executive functions, as well as affective regulation. Furthermore, the cerebellum has emerged as one of the key brain regions affected in autism. Here, we discuss our current understanding of the role of the cerebellum in autism, including evidence from genetic, molecular, clinical, behavioral, and neuroimaging studies. Cerebellar findings in autism suggest developmental differences at multiple levels of neural structure and function, indicating that the cerebellum is an important player in the complex neural underpinnings of autism spectrum disorder, with behavioral implications beyond the motor domain.
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