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Multi-voxel pattern analysis (MVPA) reveals abnormal fMRI activity in both the "core" and "extended" face network in congenital prosopagnosia.

Rivolta D, Woolgar A, Palermo R, Butko M, Schmalzl L, Williams MA - Front Hum Neurosci (2014)

Bottom Line: It is still a matter of debate which regions represent the functional substrate of congenital prosopagnosia (CP), a condition characterized by a lifelong impairment in face recognition, and affecting around 2.5% of the general population.In contrast, discriminability between faces and bodies/body-parts and objects and bodies/body-parts across the ventral visual system was typical in CPs.In sum, these findings demonstrate (i) face-object representations impairments in CP which encompass both the "core" and "extended" face regions, and (ii) superior power of MVPA in detecting group differences.

View Article: PubMed Central - PubMed

Affiliation: School of Psychology, University of East London London, UK ; Perception in Action Research Centre, and ARC Centre of Excellence in Cognition and its Disorders, Department of Cognitive Science, Faculty of Human Sciences, Macquarie University Sydney, NSW, Australia.

ABSTRACT
The ability to identify faces is mediated by a network of cortical and subcortical brain regions in humans. It is still a matter of debate which regions represent the functional substrate of congenital prosopagnosia (CP), a condition characterized by a lifelong impairment in face recognition, and affecting around 2.5% of the general population. Here, we used functional Magnetic Resonance Imaging (fMRI) to measure neural responses to faces, objects, bodies, and body-parts in a group of seven CPs and ten healthy control participants. Using multi-voxel pattern analysis (MVPA) of the fMRI data we demonstrate that neural activity within the "core" (i.e., occipital face area and fusiform face area) and "extended" (i.e., anterior temporal cortex) face regions in CPs showed reduced discriminability between faces and objects. Reduced differentiation between faces and objects in CP was also seen in the right parahippocampal cortex. In contrast, discriminability between faces and bodies/body-parts and objects and bodies/body-parts across the ventral visual system was typical in CPs. In addition to MVPA analysis, we also ran traditional mass-univariate analysis, which failed to show any group differences in face and object discriminability. In sum, these findings demonstrate (i) face-object representations impairments in CP which encompass both the "core" and "extended" face regions, and (ii) superior power of MVPA in detecting group differences.

No MeSH data available.


Related in: MedlinePlus

Groups comparison. Voxels where the local pattern of activity discriminated faces from objects more strongly in controls than in CPs: (1) right parahippocampal gyrus [34 −14 −26]; (2) right inferior temporal gyrus [40 −6 −28]; (3) right fusiform Gyrus [40 −56 −16]; (4) right inferior occipital gyrus [48 −76 −18] (threshold: t > 3.73).
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Figure 3: Groups comparison. Voxels where the local pattern of activity discriminated faces from objects more strongly in controls than in CPs: (1) right parahippocampal gyrus [34 −14 −26]; (2) right inferior temporal gyrus [40 −6 −28]; (3) right fusiform Gyrus [40 −56 −16]; (4) right inferior occipital gyrus [48 −76 −18] (threshold: t > 3.73).

Mentions: Between-group analyses: controls vs. CPs. The between-groups comparison indicated stronger face-object discrimination in controls than in CP. This group difference was evident in the fusiform gyri, right inferior occipital gyrus, right inferior temporal gyrus, and right parahippocampal gyrus (Figure 3 and Table 2). The two groups' MVPA activity did not differ when discriminating faces vs. bodies, faces vs. body parts, objects vs. bodies, and objects vs. body parts.


Multi-voxel pattern analysis (MVPA) reveals abnormal fMRI activity in both the "core" and "extended" face network in congenital prosopagnosia.

Rivolta D, Woolgar A, Palermo R, Butko M, Schmalzl L, Williams MA - Front Hum Neurosci (2014)

Groups comparison. Voxels where the local pattern of activity discriminated faces from objects more strongly in controls than in CPs: (1) right parahippocampal gyrus [34 −14 −26]; (2) right inferior temporal gyrus [40 −6 −28]; (3) right fusiform Gyrus [40 −56 −16]; (4) right inferior occipital gyrus [48 −76 −18] (threshold: t > 3.73).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4230164&req=5

Figure 3: Groups comparison. Voxels where the local pattern of activity discriminated faces from objects more strongly in controls than in CPs: (1) right parahippocampal gyrus [34 −14 −26]; (2) right inferior temporal gyrus [40 −6 −28]; (3) right fusiform Gyrus [40 −56 −16]; (4) right inferior occipital gyrus [48 −76 −18] (threshold: t > 3.73).
Mentions: Between-group analyses: controls vs. CPs. The between-groups comparison indicated stronger face-object discrimination in controls than in CP. This group difference was evident in the fusiform gyri, right inferior occipital gyrus, right inferior temporal gyrus, and right parahippocampal gyrus (Figure 3 and Table 2). The two groups' MVPA activity did not differ when discriminating faces vs. bodies, faces vs. body parts, objects vs. bodies, and objects vs. body parts.

Bottom Line: It is still a matter of debate which regions represent the functional substrate of congenital prosopagnosia (CP), a condition characterized by a lifelong impairment in face recognition, and affecting around 2.5% of the general population.In contrast, discriminability between faces and bodies/body-parts and objects and bodies/body-parts across the ventral visual system was typical in CPs.In sum, these findings demonstrate (i) face-object representations impairments in CP which encompass both the "core" and "extended" face regions, and (ii) superior power of MVPA in detecting group differences.

View Article: PubMed Central - PubMed

Affiliation: School of Psychology, University of East London London, UK ; Perception in Action Research Centre, and ARC Centre of Excellence in Cognition and its Disorders, Department of Cognitive Science, Faculty of Human Sciences, Macquarie University Sydney, NSW, Australia.

ABSTRACT
The ability to identify faces is mediated by a network of cortical and subcortical brain regions in humans. It is still a matter of debate which regions represent the functional substrate of congenital prosopagnosia (CP), a condition characterized by a lifelong impairment in face recognition, and affecting around 2.5% of the general population. Here, we used functional Magnetic Resonance Imaging (fMRI) to measure neural responses to faces, objects, bodies, and body-parts in a group of seven CPs and ten healthy control participants. Using multi-voxel pattern analysis (MVPA) of the fMRI data we demonstrate that neural activity within the "core" (i.e., occipital face area and fusiform face area) and "extended" (i.e., anterior temporal cortex) face regions in CPs showed reduced discriminability between faces and objects. Reduced differentiation between faces and objects in CP was also seen in the right parahippocampal cortex. In contrast, discriminability between faces and bodies/body-parts and objects and bodies/body-parts across the ventral visual system was typical in CPs. In addition to MVPA analysis, we also ran traditional mass-univariate analysis, which failed to show any group differences in face and object discriminability. In sum, these findings demonstrate (i) face-object representations impairments in CP which encompass both the "core" and "extended" face regions, and (ii) superior power of MVPA in detecting group differences.

No MeSH data available.


Related in: MedlinePlus