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Failure to deactivate the default mode network indicates a possible endophenotype of autism.

Spencer MD, Chura LR, Holt RJ, Suckling J, Calder AJ, Bullmore ET, Baron-Cohen S - Mol Autism (2012)

Bottom Line: We identified striking reductions in deactivation during the Embedded Figures Task in unaffected siblings compared to controls in brain regions corresponding to the default mode network.Adolescents with autism and their unaffected siblings similarly failed to deactivate regions, including posterior cingulate and bilateral inferior parietal cortex.This suggests that a failure to deactivate these regions is a functional endophenotype of autism, related to familial risk for the condition shared between individuals with autism and their siblings.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Psychiatry, Autism Research Centre, University of Cambridge, Douglas House, 18b Trumpington Road, Cambridge, CB2 8AH, UK. mds1003@cam.ac.uk.

ABSTRACT

Background: Reduced activity during cognitively demanding tasks has been reported in the default mode network in typically developing controls and individuals with autism. However, no study has investigated the default mode network (DMN) in first-degree relatives of those with autism (such as siblings) and it is not known whether atypical activation of the DMN is specific to autism or whether it is also present in unaffected relatives. Here we use functional magnetic resonance imaging to investigate the pattern of task-related deactivation during completion of a visual search task, the Embedded Figures Task, in teenagers with autism, their unaffected siblings and typically developing controls.

Findings: We identified striking reductions in deactivation during the Embedded Figures Task in unaffected siblings compared to controls in brain regions corresponding to the default mode network. Adolescents with autism and their unaffected siblings similarly failed to deactivate regions, including posterior cingulate and bilateral inferior parietal cortex.

Conclusions: This suggests that a failure to deactivate these regions is a functional endophenotype of autism, related to familial risk for the condition shared between individuals with autism and their siblings.

No MeSH data available.


Related in: MedlinePlus

Task-related deactivations - the neural response to the control task versus the Embedded Figures Task condition, in controls (n = 40), unaffected siblings (n = 40) and adolescents with autism (n = 38). Activation maps indicate neural response to CT versus EFT conditions, corrected for multiple comparisons at whole brain P <0.05 FWE-corrected overlaid onto the canonical MNI152 template brain image (axial section, z-coordinate indicated in MNI space), with the colored bar indicating the T-value of the plotted activation differences. CT, control task; EFT, Embedded Figures Task; FWE, family-wise error; MNI, Montreal Neurological Institute.
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Figure 1: Task-related deactivations - the neural response to the control task versus the Embedded Figures Task condition, in controls (n = 40), unaffected siblings (n = 40) and adolescents with autism (n = 38). Activation maps indicate neural response to CT versus EFT conditions, corrected for multiple comparisons at whole brain P <0.05 FWE-corrected overlaid onto the canonical MNI152 template brain image (axial section, z-coordinate indicated in MNI space), with the colored bar indicating the T-value of the plotted activation differences. CT, control task; EFT, Embedded Figures Task; FWE, family-wise error; MNI, Montreal Neurological Institute.

Mentions: To characterize the patterns of activation within the brain in the three participant groups, the first-level contrast images for each study group were taken through to a second-level analysis employing a random-effects model, with age and sex specified as covariates. Group-level activation maps (Figure1) were generated with a global threshold set at P <0.05 following correction for multiple comparisons on a whole brain level family-wise error (FWE) basis, and with a cluster extent (kE) threshold set at 10 voxels.


Failure to deactivate the default mode network indicates a possible endophenotype of autism.

Spencer MD, Chura LR, Holt RJ, Suckling J, Calder AJ, Bullmore ET, Baron-Cohen S - Mol Autism (2012)

Task-related deactivations - the neural response to the control task versus the Embedded Figures Task condition, in controls (n = 40), unaffected siblings (n = 40) and adolescents with autism (n = 38). Activation maps indicate neural response to CT versus EFT conditions, corrected for multiple comparisons at whole brain P <0.05 FWE-corrected overlaid onto the canonical MNI152 template brain image (axial section, z-coordinate indicated in MNI space), with the colored bar indicating the T-value of the plotted activation differences. CT, control task; EFT, Embedded Figures Task; FWE, family-wise error; MNI, Montreal Neurological Institute.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3539860&req=5

Figure 1: Task-related deactivations - the neural response to the control task versus the Embedded Figures Task condition, in controls (n = 40), unaffected siblings (n = 40) and adolescents with autism (n = 38). Activation maps indicate neural response to CT versus EFT conditions, corrected for multiple comparisons at whole brain P <0.05 FWE-corrected overlaid onto the canonical MNI152 template brain image (axial section, z-coordinate indicated in MNI space), with the colored bar indicating the T-value of the plotted activation differences. CT, control task; EFT, Embedded Figures Task; FWE, family-wise error; MNI, Montreal Neurological Institute.
Mentions: To characterize the patterns of activation within the brain in the three participant groups, the first-level contrast images for each study group were taken through to a second-level analysis employing a random-effects model, with age and sex specified as covariates. Group-level activation maps (Figure1) were generated with a global threshold set at P <0.05 following correction for multiple comparisons on a whole brain level family-wise error (FWE) basis, and with a cluster extent (kE) threshold set at 10 voxels.

Bottom Line: We identified striking reductions in deactivation during the Embedded Figures Task in unaffected siblings compared to controls in brain regions corresponding to the default mode network.Adolescents with autism and their unaffected siblings similarly failed to deactivate regions, including posterior cingulate and bilateral inferior parietal cortex.This suggests that a failure to deactivate these regions is a functional endophenotype of autism, related to familial risk for the condition shared between individuals with autism and their siblings.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Psychiatry, Autism Research Centre, University of Cambridge, Douglas House, 18b Trumpington Road, Cambridge, CB2 8AH, UK. mds1003@cam.ac.uk.

ABSTRACT

Background: Reduced activity during cognitively demanding tasks has been reported in the default mode network in typically developing controls and individuals with autism. However, no study has investigated the default mode network (DMN) in first-degree relatives of those with autism (such as siblings) and it is not known whether atypical activation of the DMN is specific to autism or whether it is also present in unaffected relatives. Here we use functional magnetic resonance imaging to investigate the pattern of task-related deactivation during completion of a visual search task, the Embedded Figures Task, in teenagers with autism, their unaffected siblings and typically developing controls.

Findings: We identified striking reductions in deactivation during the Embedded Figures Task in unaffected siblings compared to controls in brain regions corresponding to the default mode network. Adolescents with autism and their unaffected siblings similarly failed to deactivate regions, including posterior cingulate and bilateral inferior parietal cortex.

Conclusions: This suggests that a failure to deactivate these regions is a functional endophenotype of autism, related to familial risk for the condition shared between individuals with autism and their siblings.

No MeSH data available.


Related in: MedlinePlus