Basic level category structure emerges gradually across human ventral visual cortex

J Cogn Neurosci. 2015 Jul;27(7):1427-46. doi: 10.1162/jocn_a_00790. Epub 2015 Mar 26.

Abstract

Objects can be simultaneously categorized at multiple levels of specificity ranging from very broad ("natural object") to very distinct ("Mr. Woof"), with a mid-level of generality (basic level: "dog") often providing the most cognitively useful distinction between categories. It is unknown, however, how this hierarchical representation is achieved in the brain. Using multivoxel pattern analyses, we examined how well each taxonomic level (superordinate, basic, and subordinate) of real-world object categories is represented across occipitotemporal cortex. We found that, although in early visual cortex objects are best represented at the subordinate level (an effect mostly driven by low-level feature overlap between objects in the same category), this advantage diminishes compared to the basic level as we move up the visual hierarchy, disappearing in object-selective regions of occipitotemporal cortex. This pattern stems from a combined increase in within-category similarity (category cohesion) and between-category dissimilarity (category distinctiveness) of neural activity patterns at the basic level, relative to both subordinate and superordinate levels, suggesting that successive visual areas may be optimizing basic level representations.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Brain Mapping
  • Cerebral Cortex / physiology*
  • Female
  • Humans
  • Judgment / physiology
  • Magnetic Resonance Imaging
  • Male
  • Models, Neurological*
  • Neuropsychological Tests
  • Pattern Recognition, Visual / physiology*
  • Photic Stimulation
  • Reaction Time
  • Visual Cortex / physiology*
  • Young Adult