title: Smooth versus Textured Surfaces: Feature-Based Category Selectivity in Human Visual Cortex.
abstract: In fMRI studies, human lateral occipital (LO) cortex is thought to respond selectively to images of objects, compared with nonobjects. However, it remains unresolved whether all objects evoke equivalent levels of activity in LO, and, if not, which image features produce stronger activation. Here, we used an unbiased parametric texture model to predict preferred versus nonpreferred stimuli in LO. Observation and psychophysical results showed that predicted preferred stimuli (both objects and nonobjects) had smooth (rather than textured) surfaces. These predictions were confirmed using fMRI, for objects and nonobjects. Similar preferences were also found in the fusiform face area (FFA). Consistent with this: (1) FFA and LO responded more strongly to nonfreckled (smooth) faces, compared with otherwise identical freckled (textured) faces; and (2) strong functional connections were found between LO and FFA. Thus, LO and FFA may be part of an information-processing stream distinguished by feature-based category selectivity (smooth > textured).
authors.affiliation: Athinioula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital , Charlestown, Massachusetts 02129.
authors.forename: Cesar
authors.identifier: 0000-0003-2470-5606
authors.initials: C
authors.lastname: Echavarria
authors.affiliation: Athinioula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129; Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115.
authors.forename: Shahin
authors.identifier: 0000-0002-7546-9976
authors.initials: S
authors.lastname: Nasr
authors.affiliation: Athinioula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129; Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115.
authors.forename: Roger
authors.initials: R
authors.lastname: Tootell
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000502:physiology; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D021641:Recognition, Psychology / Q000502:physiology; D014793:Visual Cortex / Q000000981:diagnostic imaging / Q000502:physiology*; D055815:Young Adult
keywords: FFA; LO; fMRI; functional connectivity; texture