Structural similarity exerts opposing effects on perceptual differentiation and categorization: an FMRI study.
We manipulated the degree of structural similarity between objects that had to be matched either according to whether they represented the same object (perceptual matching) or belonged to the same category (conceptual matching). Behaviorally, performance improved as a linear function of increased structural similarity during conceptual matching but deteriorated as a linear function of increased structural similarity during perceptual matching. These effects were mirrored in fMRI recordings where activation in several ventral posterior areas exhibited a similar interaction between match type and structural similarity. Our findings provide direct support for the notion that structural similarity exerts opposing effects on classification depending on whether objects are to be perceptually differentiated or categorized-a notion that has been based on rather circumstantial evidence. In particular, the finding that structural similarity plays a major role in categorization of instances according to taxonomy challenges the view that the organization of superordinate categories is not driven by shared structural features.
University of Southern Denmark.
Christian
C
Gerlach
Xun
X
Zhu
Jane E
JE
Joseph
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping; D003210:Concept Formation / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D011930:Reaction Time / Q000502:physiology; D021641:Recognition, Psychology / Q000502:physiology*; D014793:Visual Cortex / Q000098:blood supply / Q000502:physiology*; D014795:Visual Pathways / Q000098:blood supply / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
D010100:Oxygen