TY - JOUR
T1 - Typicality sharpens category representations in object-selective cortex
AU - Iordan, Marius Cătălin
AU - Greene, Michelle R.
AU - Beck, Diane M.
AU - Fei-Fei, Li
N1 - Publisher Copyright:
© 2016 Elsevier Inc.
PY - 2016/7/1
Y1 - 2016/7/1
N2 - The purpose of categorization is to identify generalizable classes of objects whose members can be treated equivalently. Within a category, however, some exemplars are more representative of that concept than others. Despite long-standing behavioral effects, little is known about how typicality influences the neural representation of real-world objects from the same category. Using fMRI, we showed participants 64 subordinate object categories (exemplars) grouped into 8 basic categories. Typicality for each exemplar was assessed behaviorally and we used several multi-voxel pattern analyses to characterize how typicality affects the pattern of responses elicited in early visual and object-selective areas: V1, V2, V3v, hV4, LOC. We found that in LOC, but not in early areas, typical exemplars elicited activity more similar to the central category tendency and created sharper category boundaries than less typical exemplars, suggesting that typicality enhances within-category similarity and between-category dissimilarity. Additionally, we uncovered a brain region (cIPL) where category boundaries favor less typical categories. Our results suggest that typicality may constitute a previously unexplored principle of organization for intra-category neural structure and, furthermore, that this representation is not directly reflected in image features describing natural input, but rather built by the visual system at an intermediate processing stage.
AB - The purpose of categorization is to identify generalizable classes of objects whose members can be treated equivalently. Within a category, however, some exemplars are more representative of that concept than others. Despite long-standing behavioral effects, little is known about how typicality influences the neural representation of real-world objects from the same category. Using fMRI, we showed participants 64 subordinate object categories (exemplars) grouped into 8 basic categories. Typicality for each exemplar was assessed behaviorally and we used several multi-voxel pattern analyses to characterize how typicality affects the pattern of responses elicited in early visual and object-selective areas: V1, V2, V3v, hV4, LOC. We found that in LOC, but not in early areas, typical exemplars elicited activity more similar to the central category tendency and created sharper category boundaries than less typical exemplars, suggesting that typicality enhances within-category similarity and between-category dissimilarity. Additionally, we uncovered a brain region (cIPL) where category boundaries favor less typical categories. Our results suggest that typicality may constitute a previously unexplored principle of organization for intra-category neural structure and, furthermore, that this representation is not directly reflected in image features describing natural input, but rather built by the visual system at an intermediate processing stage.
KW - Categorization
KW - Object
KW - Typicality
KW - fMRI
UR - http://www.scopus.com/inward/record.url?scp=84963976229&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84963976229&partnerID=8YFLogxK
U2 - 10.1016/j.neuroimage.2016.04.012
DO - 10.1016/j.neuroimage.2016.04.012
M3 - Article
C2 - 27079531
AN - SCOPUS:84963976229
SN - 1053-8119
VL - 134
SP - 170
EP - 179
JO - NeuroImage
JF - NeuroImage
ER -