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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

Within-group analysis: Voxels where the local pattern of activation discriminates between (A) object vs. body and (B) object vs. body part (threshold: t > 8.40). Effects are shown for controls (left) and CPs (right).
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Figure 2: Within-group analysis: Voxels where the local pattern of activation discriminates between (A) object vs. body and (B) object vs. body part (threshold: t > 8.40). Effects are shown for controls (left) and CPs (right).

Mentions: Within-group analyses: controls and CPs. Controls showed an above chance discrimination pattern between faces and objects over the fusiform gyri and inferior occipital gyri (see Figure 1 and Table 2). Controls also showed above chance discrimination between faces and bodies in the fusiform gyri, left middle occipital gyrus and lateral inferior occipital gyri (see Figure 1 and Table 2), and above chance discrimination between faces and body parts over fusiform gyri, left inferior temporal gyrus, lingual gyri, left superior occipital gyrus, right middle occipital gyrus, and lateral inferior occipital gyri (see Figure 1 and Table 2). Controls' pattern of activity could above chance discriminate between object and bodies over the left inferior occipital gyrus, right middle occipital gyrus, and right fusiform gyrus (see Figure 2 and Table 2). Finally, controls showed an above chance discrimination pattern between object and body parts over the inferior occipital gyrus (bilateral), fusiform gyrus (bilateral), right lingual gyrus, left inferior temporal gyrus, and right middle temporal gyrus (see Figure 2 and Table 2).


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)

Within-group analysis: Voxels where the local pattern of activation discriminates between (A) object vs. body and (B) object vs. body part (threshold: t > 8.40). Effects are shown for controls (left) and CPs (right).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 2: Within-group analysis: Voxels where the local pattern of activation discriminates between (A) object vs. body and (B) object vs. body part (threshold: t > 8.40). Effects are shown for controls (left) and CPs (right).
Mentions: Within-group analyses: controls and CPs. Controls showed an above chance discrimination pattern between faces and objects over the fusiform gyri and inferior occipital gyri (see Figure 1 and Table 2). Controls also showed above chance discrimination between faces and bodies in the fusiform gyri, left middle occipital gyrus and lateral inferior occipital gyri (see Figure 1 and Table 2), and above chance discrimination between faces and body parts over fusiform gyri, left inferior temporal gyrus, lingual gyri, left superior occipital gyrus, right middle occipital gyrus, and lateral inferior occipital gyri (see Figure 1 and Table 2). Controls' pattern of activity could above chance discriminate between object and bodies over the left inferior occipital gyrus, right middle occipital gyrus, and right fusiform gyrus (see Figure 2 and Table 2). Finally, controls showed an above chance discrimination pattern between object and body parts over the inferior occipital gyrus (bilateral), fusiform gyrus (bilateral), right lingual gyrus, left inferior temporal gyrus, and right middle temporal gyrus (see Figure 2 and Table 2).

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