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Location, Location, Location: Alterations in the Functional Topography of Face- but not Object- or Place-Related Cortex in Adolescents with Autism.

Scherf KS, Luna B, Minshew N, Behrmann M - Front Hum Neurosci (2010)

Bottom Line: With these data, we mapped the functional topography of category-selective activation for faces bilaterally in the fusiform gyrus, occipital face area, and posterior superior temporal sulcus.Additionally, we mapped category-selective activation for objects in the lateral occipital area and for places in the parahippocampal place area in the two groups.Our findings do not indicate a generalized disruption in the development of the entire ventral visual pathway in autism.

View Article: PubMed Central - PubMed

Affiliation: Cognitive Neuroscience Laboratory, Department of Psychology, Center for the Neural Basis of Cognition, Carnegie Mellon University Pittsburgh, PA, USA.

ABSTRACT
In autism, impairments in face processing are a relatively recent discovery, but have quickly become a widely accepted aspect of the behavioral profile. Only a handful of studies have investigated potential atypicalities in autism in the development of the neural substrates mediating face processing. High-functioning individuals with autism (HFA) and matched typically developing (TD) controls watched dynamic movie vignettes of faces, common objects, buildings, and scenes of navigation while undergoing an fMRI scan. With these data, we mapped the functional topography of category-selective activation for faces bilaterally in the fusiform gyrus, occipital face area, and posterior superior temporal sulcus. Additionally, we mapped category-selective activation for objects in the lateral occipital area and for places in the parahippocampal place area in the two groups. Our findings do not indicate a generalized disruption in the development of the entire ventral visual pathway in autism. Instead, our results suggest that the functional topography of face-related cortex is selectively disrupted in autism and that this alteration is present in early adolescence. Furthermore, for those HFA adolescents who do exhibit face-selective activation, this activation tends to be located in traditionally object-related regions, which supports the hypothesis that perceptual processing of faces in autism may be more akin to the perceptual processing of common objects in TD individuals.

No MeSH data available.


Related in: MedlinePlus

Category-selective topography within each group. Contrast maps for each object category from the group level random effects GLM showing average face-, object-, and place-related activation maps generated from the whole brain analyses for each group. Activation is mapped onto the ventral projection and the lateral hemispheres of a single representative inflated brain for the (A) typically developing adolescents and (B) adolescents with autism, when all contrasts are corrected at p < 0.05. Although there were small loci of face-selective activation in the right and left FG in the HFA group, these ROIs are so ventral that they do not project onto the inflated brain (see Table 1 for coordinates and size of ROIs) (C) To evaluate whether face-selective activation is present in more dorsal and/or anterior portions of the fusiform gyrus in the HFA adolescents as a group, the threshold on just the group level face contrast was reduced to a corrected p < 0.10. A larger face-selective ROI emerged in the right fusiform gyrus and the right STS. FFA, fusiform face area; FG, fusiform gyrus; OFA, occipital face area; STS, superior temporal sulcus; LO, lateral occipital object area; PPA, parahippocampal place area.
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Figure 1: Category-selective topography within each group. Contrast maps for each object category from the group level random effects GLM showing average face-, object-, and place-related activation maps generated from the whole brain analyses for each group. Activation is mapped onto the ventral projection and the lateral hemispheres of a single representative inflated brain for the (A) typically developing adolescents and (B) adolescents with autism, when all contrasts are corrected at p < 0.05. Although there were small loci of face-selective activation in the right and left FG in the HFA group, these ROIs are so ventral that they do not project onto the inflated brain (see Table 1 for coordinates and size of ROIs) (C) To evaluate whether face-selective activation is present in more dorsal and/or anterior portions of the fusiform gyrus in the HFA adolescents as a group, the threshold on just the group level face contrast was reduced to a corrected p < 0.10. A larger face-selective ROI emerged in the right fusiform gyrus and the right STS. FFA, fusiform face area; FG, fusiform gyrus; OFA, occipital face area; STS, superior temporal sulcus; LO, lateral occipital object area; PPA, parahippocampal place area.

Mentions: Category selectivity was initially evaluated separately in each group by submitting the individual subject timeseries images to a whole brain voxelwise random effects GLM in which the category was a fixed factor and participant was a random factor. This GLM generates beta weights for each individual participant in each condition (i.e., visual category), which were then submitted to two-tailed t-tests in each voxel to determine the relative magnitude of category selectivity. The group level contrast maps (e.g., [(faces − (objects + buildings + navigation)]) were corrected for multiple comparisons using a Monte Carlo simulation. To achieve p < 0.05 significance, the simulation required a minimum of four contiguous 3 mm voxels with a t-value ≥2.3. These group level maps of the topography of category-selective activation for each group are shown in Figure 1.


Location, Location, Location: Alterations in the Functional Topography of Face- but not Object- or Place-Related Cortex in Adolescents with Autism.

Scherf KS, Luna B, Minshew N, Behrmann M - Front Hum Neurosci (2010)

Category-selective topography within each group. Contrast maps for each object category from the group level random effects GLM showing average face-, object-, and place-related activation maps generated from the whole brain analyses for each group. Activation is mapped onto the ventral projection and the lateral hemispheres of a single representative inflated brain for the (A) typically developing adolescents and (B) adolescents with autism, when all contrasts are corrected at p < 0.05. Although there were small loci of face-selective activation in the right and left FG in the HFA group, these ROIs are so ventral that they do not project onto the inflated brain (see Table 1 for coordinates and size of ROIs) (C) To evaluate whether face-selective activation is present in more dorsal and/or anterior portions of the fusiform gyrus in the HFA adolescents as a group, the threshold on just the group level face contrast was reduced to a corrected p < 0.10. A larger face-selective ROI emerged in the right fusiform gyrus and the right STS. FFA, fusiform face area; FG, fusiform gyrus; OFA, occipital face area; STS, superior temporal sulcus; LO, lateral occipital object area; PPA, parahippocampal place area.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2904054&req=5

Figure 1: Category-selective topography within each group. Contrast maps for each object category from the group level random effects GLM showing average face-, object-, and place-related activation maps generated from the whole brain analyses for each group. Activation is mapped onto the ventral projection and the lateral hemispheres of a single representative inflated brain for the (A) typically developing adolescents and (B) adolescents with autism, when all contrasts are corrected at p < 0.05. Although there were small loci of face-selective activation in the right and left FG in the HFA group, these ROIs are so ventral that they do not project onto the inflated brain (see Table 1 for coordinates and size of ROIs) (C) To evaluate whether face-selective activation is present in more dorsal and/or anterior portions of the fusiform gyrus in the HFA adolescents as a group, the threshold on just the group level face contrast was reduced to a corrected p < 0.10. A larger face-selective ROI emerged in the right fusiform gyrus and the right STS. FFA, fusiform face area; FG, fusiform gyrus; OFA, occipital face area; STS, superior temporal sulcus; LO, lateral occipital object area; PPA, parahippocampal place area.
Mentions: Category selectivity was initially evaluated separately in each group by submitting the individual subject timeseries images to a whole brain voxelwise random effects GLM in which the category was a fixed factor and participant was a random factor. This GLM generates beta weights for each individual participant in each condition (i.e., visual category), which were then submitted to two-tailed t-tests in each voxel to determine the relative magnitude of category selectivity. The group level contrast maps (e.g., [(faces − (objects + buildings + navigation)]) were corrected for multiple comparisons using a Monte Carlo simulation. To achieve p < 0.05 significance, the simulation required a minimum of four contiguous 3 mm voxels with a t-value ≥2.3. These group level maps of the topography of category-selective activation for each group are shown in Figure 1.

Bottom Line: With these data, we mapped the functional topography of category-selective activation for faces bilaterally in the fusiform gyrus, occipital face area, and posterior superior temporal sulcus.Additionally, we mapped category-selective activation for objects in the lateral occipital area and for places in the parahippocampal place area in the two groups.Our findings do not indicate a generalized disruption in the development of the entire ventral visual pathway in autism.

View Article: PubMed Central - PubMed

Affiliation: Cognitive Neuroscience Laboratory, Department of Psychology, Center for the Neural Basis of Cognition, Carnegie Mellon University Pittsburgh, PA, USA.

ABSTRACT
In autism, impairments in face processing are a relatively recent discovery, but have quickly become a widely accepted aspect of the behavioral profile. Only a handful of studies have investigated potential atypicalities in autism in the development of the neural substrates mediating face processing. High-functioning individuals with autism (HFA) and matched typically developing (TD) controls watched dynamic movie vignettes of faces, common objects, buildings, and scenes of navigation while undergoing an fMRI scan. With these data, we mapped the functional topography of category-selective activation for faces bilaterally in the fusiform gyrus, occipital face area, and posterior superior temporal sulcus. Additionally, we mapped category-selective activation for objects in the lateral occipital area and for places in the parahippocampal place area in the two groups. Our findings do not indicate a generalized disruption in the development of the entire ventral visual pathway in autism. Instead, our results suggest that the functional topography of face-related cortex is selectively disrupted in autism and that this alteration is present in early adolescence. Furthermore, for those HFA adolescents who do exhibit face-selective activation, this activation tends to be located in traditionally object-related regions, which supports the hypothesis that perceptual processing of faces in autism may be more akin to the perceptual processing of common objects in TD individuals.

No MeSH data available.


Related in: MedlinePlus