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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

Commonalities in task-related deactivation across the three groups. Activation map indicates results of conjunction analysis, signifying commonalities in significant neural response to CT versus EFT conditions across the three groups, 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. The graph indicates activation differences (means ± s.e.m.) between the fMRI response in the CT and EFT conditions. Note that the P values indicated on the graph additionally take into account age and sex as covariates, and hence do not directly correspond to the degree of apparent separation of error bars. CT, control task; EFT, Embedded Figures Task; fMRI, functional magnetic resonance imaging; FWE, family-wise error; MNI, Montreal Neurological Institute; s.e.m., standard error of the mean.
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Figure 2: Commonalities in task-related deactivation across the three groups. Activation map indicates results of conjunction analysis, signifying commonalities in significant neural response to CT versus EFT conditions across the three groups, 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. The graph indicates activation differences (means ± s.e.m.) between the fMRI response in the CT and EFT conditions. Note that the P values indicated on the graph additionally take into account age and sex as covariates, and hence do not directly correspond to the degree of apparent separation of error bars. CT, control task; EFT, Embedded Figures Task; fMRI, functional magnetic resonance imaging; FWE, family-wise error; MNI, Montreal Neurological Institute; s.e.m., standard error of the mean.

Mentions: As indicated in Figure2 and Table1, conjunction analysis demonstrated commonalities in the pattern of deactivation across the three groups.After FWE-correction for multiple comparisons on a whole brain level, commonalities of significant deactivation were found in the right inferior parietal cortex (RIPC; P <0.001), posterior cingulate cortex (PCC; P <0.001), left inferior parietal cortex (LIPC; P <0.001), left superior temporal sulcus (STS) (P = 0.001), left anterior prefrontal cortex (P = 0.006) and right STS (P = 0.014).


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)

Commonalities in task-related deactivation across the three groups. Activation map indicates results of conjunction analysis, signifying commonalities in significant neural response to CT versus EFT conditions across the three groups, 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. The graph indicates activation differences (means ± s.e.m.) between the fMRI response in the CT and EFT conditions. Note that the P values indicated on the graph additionally take into account age and sex as covariates, and hence do not directly correspond to the degree of apparent separation of error bars. CT, control task; EFT, Embedded Figures Task; fMRI, functional magnetic resonance imaging; FWE, family-wise error; MNI, Montreal Neurological Institute; s.e.m., standard error of the mean.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 2: Commonalities in task-related deactivation across the three groups. Activation map indicates results of conjunction analysis, signifying commonalities in significant neural response to CT versus EFT conditions across the three groups, 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. The graph indicates activation differences (means ± s.e.m.) between the fMRI response in the CT and EFT conditions. Note that the P values indicated on the graph additionally take into account age and sex as covariates, and hence do not directly correspond to the degree of apparent separation of error bars. CT, control task; EFT, Embedded Figures Task; fMRI, functional magnetic resonance imaging; FWE, family-wise error; MNI, Montreal Neurological Institute; s.e.m., standard error of the mean.
Mentions: As indicated in Figure2 and Table1, conjunction analysis demonstrated commonalities in the pattern of deactivation across the three groups.After FWE-correction for multiple comparisons on a whole brain level, commonalities of significant deactivation were found in the right inferior parietal cortex (RIPC; P <0.001), posterior cingulate cortex (PCC; P <0.001), left inferior parietal cortex (LIPC; P <0.001), left superior temporal sulcus (STS) (P = 0.001), left anterior prefrontal cortex (P = 0.006) and right STS (P = 0.014).

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