title: Connectivity-based constraints on category-specificity in the ventral object processing pathway.
abstract: Recent efforts to characterize visual object representations in the ventral object processing pathway in the human brain have led to contrasting proposals about the causes of neural specificity for different categories. Here we use multivariate techniques in a novel way to relate patterns of functional connectivity to patterns of stimulus preferences. Stimulus preferences were measured throughout the ventral stream to tools, animals, faces and places; separately, we measured the strength of functional connectivity of each voxel in the ventral stream to category-preferring regions outside the ventral stream. Multivariate analyses were then performed over ventral stream voxels, relating 'category-preferences' to 'functional connectivity preferences'. We show that the relation of those two measures doubly dissociates 'tools' and 'places', within what is ostensibly 'place' selective cortex (parahippocampal gyrus). Specifically, in the parahippocampal gyrus, functional connectivity to the left inferior parietal lobule is selectively related to stimulus preferences for tools (and not places), while functional connectivity to retrosplenial cortex is selectively related to place preferences (and not tools preferences). These findings indicate that functional connectivity can be used to index representational content rather than just provide an understanding of 'which regions are talking to which regions'. We suggest that the connectivity of the brain is what drives category-specificity in the ventral stream, and that if this is correct, then understanding the connectivity of the ventral stream will be key to understanding the causes and function of category-specific neural organization.
authors.affiliation: Department of Brain and Cognitive Sciences, University of Rochester, 14627, United States.
authors.forename: Quanjing
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Brain and Cognitive Sciences, University of Rochester, 14627, United States; Center for Visual Science, University of Rochester, 14627, United States.
authors.forename: Frank E
authors.initials: FE
authors.lastname: Garcea
authors.affiliation: Proaction Laboratory, Faculty of Psychology and Education Sciences, University of Coimbra, 3001-802, Portugal; Faculty of Psychology and Education Sciences, University of Coimbra, 3001-802, Portugal.
authors.forename: Jorge
authors.initials: J
authors.lastname: Almeida
authors.affiliation: Department of Brain and Cognitive Sciences, University of Rochester, 14627, United States; Center for Visual Science, University of Rochester, 14627, United States; Department of Neurosurgery, University of Rochester, 14627, United States. Electronic address: mahon@rcbi.rochester.edu.
authors.forename: Bradford Z
authors.initials: BZ
authors.lastname: Mahon
mesh_terms: D001931:Brain Mapping; D003210:Concept Formation / Q000502:physiology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D010296:Parietal Lobe / Q000000981:diagnostic imaging / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D014795:Visual Pathways / Q000000981:diagnostic imaging / Q000502:physiology*; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: Category specificity; Functional connectivity; Mvpa; Resting-state fmri; Ventral stream