Abnormal Variability and Distribution of Functional Maps in Autism: An fMRI Study of Visuomotor Learning

Müller, Ralph Axel; Kleinhans, Natalia M.; Kemmotsu, Nobuko; Pierce, Karen; Courchesne, Eric

doi:10.1176/appi.ajp.160.10.1847

Cited by 153 publications

(117 citation statements)

References 101 publications

Supporting

Mentioning

102

Contrasting

Unclassified

Order By: Relevance

“…Possible involvement of sub-cortical, especially thalamic, structures in this task is noteworthy because two studies of multimodal integration found evidence of abnormal thalamic activity in subjects with ASD. Abnormal thalamic activation was found in subjects with autism during auditory-visual integration of emotional cues (Hall et al, 2003), and in a study of visuo-motor integration subjects with autism showed abnormal activation patterns which were hypothesized to be related to developmental disturbances in thalamocortical afferents (Muller et al, 2003). Moreover, there are indications that the thalamus is smaller in men with high-functioning autism than in normal control men (Tsatsanis et al, 2003).…”

Section: Discussionmentioning

confidence: 98%

Brief Report: Can You See What is Not There? Low-level Auditory–visual Integration in Autism Spectrum Disorder

Smagt

Engeland

Kemner

2007

J Autism Dev Disord

View full text Add to dashboard Cite

Patients diagnosed with Autism Spectrum Disorder, show impaired integration of information across different senses. The processing-level from which this impairment originates, however, remains unclear. We investigated low-level integration of auditory and visual stimuli in subjects with Autism Spectrum Disorder. High-functioning adult subjects with Autism Spectrum Disorder as well as age-and IQ-matched adults were tested using a task that evokes illusory visual stimuli, by presenting sounds concurrently with visual flashes. In both groups the number of sounds presented significantly affected the number of flashes perceived, yet there was no difference between groups. This finding implicates that any problems arising from integrating auditory and visual information must stem from higher processing stages in high-functioning adults with Autism Spectrum Disorder.

show abstract

Section: Discussionmentioning

confidence: 98%

Brief Report: Can You See What is Not There? Low-level Auditory–visual Integration in Autism Spectrum Disorder

Smagt

Engeland

Kemner

2007

J Autism Dev Disord

View full text Add to dashboard Cite

show abstract

“…This finding suggests that voxel placement may determine whether neural abnormalities will be observed in ASD. Other brain imaging studies which investigated the frontal lobes in their entirety have also consistently found abnormalities such as reversed asymmetries in language association areas (Herbert et al, 2005), decreased metabolism (Zilbovicius et al, 1995), abnormal patterns of activation (Just et al, 2004;Luna et al, 2002;Muller et al, 2003;Pierce et al, 2004;Silk et al, 2006), and white matter abnormalities (Barnea-Goraly et al, 2004;Carper et al, 2002;Herbert et al, 2004). As such, while ASD almost certainly involves frontal lobe abnormalities, the exact nature of the abnormalities requires further characterization.…”

Section: Discussionmentioning

confidence: 99%

“…In the current 1 H MRS study, four a-priori regions of interest (ROI) (frontal lobe, cerebellar hemisphere, cerebellar vermis, and parietal lobe) were selected based on structural and functional abnormalities previously reported in ASD (Allen et al, 2004;Carper and Courchesne, 2005;Ciesielski et al, 1997;Courchesne et al, 1993;Courchesne et al, 1994a;Courchesne et al, 1994b;Courchesne et al, 1988;Hashimoto et al, 1995;Kaufmann et al, 2003;Kleinhans et al, 2005b;Luna et al, 2002;Muller et al, 2003;Townsend et al, 1999). The occipital lobe was also included to serve as a control region, based on reports that the occipital lobes appear to be less affected in ASD (Buxhoeveden et al, 2006;Carper et al, 2002;Hadjikhani et al, 2004;Salmond et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

N-acetyl aspartate in autism spectrum disorders: Regional effects and relationship to fMRI activation

et al. 2007

Self Cite

View full text Add to dashboard Cite

Rapid progress in our understanding of macrostructural abnormalities in autism spectrum disorders (ASD) has occurred in recent years. However, the relationship between the integrity of neural tissue and neural function has not been previously investigated. Single-voxel proton magnetic resonance spectroscopy and functional magnetic resonance imaging of an executive functioning task was obtained in 13 high functioning adolescents and adults with ASD and 13 agematched controls. The ASD group showed significant reductions in N-acetyl aspartate (NAA) in all brain regions combined and a specific reduction in left frontal cortex compared to controls. Regression analyses revealed a significant group interaction effect between frontal and cerebellar NAA. In addition, a significant positive semi-partial correlation between left frontal lobe NAA and frontal lobe functional activation was found in the ASD group. These findings suggest that widespread neuronal dysfunction is present in high functioning individuals with ASD. Hypothesized developmental links between frontal and cerebellar vermis neural abnormalities were supported, in that impaired neuronal functioning in the vermis was associated with impaired neuronal functioning in the frontal lobes in the ASD group. Furthermore, this study provided the first direct evidence of the relationship between abnormal functional activation in prefrontal cortex and neuronal dysfunction in ASD.

show abstract

“…Levitt and colleagues found altered cortical sulcal maps in children with autism [77]. Such changes in the architecture of important cortical processing areas could underlie the functional deficits in the development of cortical sound processing [51], visual-motor maps [88] and face recognition [42,94] that are observed in autism.…”

Section: Discussionmentioning

confidence: 99%

Modeling early cortical serotonergic deficits in autism

Boylan

Blue

Höhmann

2007

Behavioural Brain Research

View full text Add to dashboard Cite

Autism is a developmental brain disorder characterized by deficits in social interaction, language and behavior. Brain imaging studies demonstrate increased cerebral cortical volumes and micro-and macroscopic neuroanatomic changes in children with this disorder. Alterations in forebrain serotonergic function may underlie the neuroanatomic and behavioral features of autism. Serotonin is involved in neuronal growth and plasticity and these actions are likely mediated via serotonergic and glutamatergic receptors. Few animal models of autism have been described that replicate both etiology and pathophysiology. We report here on a selective serotonin (5-HT) depletion model of this disorder in neonatal mice that mimics neurochemical and structural changes in cortex and, in addition, displays a behavioral phenotype consistent with autism. Newborn male and female mice were depleted of forebrain 5-HT with injections of the serotonergic neurotoxin, 5,7-dihydroxytryptamine (5,7-DHT), into the bilateral medial forebrain bundle (mfb). Behavioral testing of these animals as adults revealed alterations in social, sensory and stereotypic behaviors. Lesioned mice showed significantly increased cortical width. Serotonin immunocytochemistry showed a dramatic long-lasting depletion of 5-HT containing fibers in cerebral cortex until postnatal day (PND) 60. Autoradiographic binding to high affinity 5-HT transporters was significantly but transiently reduced in cerebral cortex of 5,7-DHT-depleted mice. AMPA glutamate receptor binding was decreased at PND 15. We hypothesize that increased cerebral cortical volume and sensorimotor, cognitive and social deficits observed in both 5-HT-depleted animals and in individuals with autism, may be the result of deficiencies in timely axonal pruning to key cerebral cortical areas.

show abstract

Abnormal Variability and Distribution of Functional Maps in Autism: An fMRI Study of Visuomotor Learning

Abstract: The results support earlier findings of abnormal variability and scatter of functional maps in autism. They are consistent with evidence from other studies suggesting early-onset disturbances in the development of cerebello-thalamo-cortical pathways in autism.

Cited by 153 publications

References 101 publications

Brief Report: Can You See What is Not There? Low-level Auditory–visual Integration in Autism Spectrum Disorder

Brief Report: Can You See What is Not There? Low-level Auditory–visual Integration in Autism Spectrum Disorder

N-acetyl aspartate in autism spectrum disorders: Regional effects and relationship to fMRI activation

Modeling early cortical serotonergic deficits in autism

Contact Info

Product

Resources

About