[DSRP Evidence](https://dsrpevidence.org/)

# Category Learning Selectively Enhances Representations of Boundary-Adjacent Exemplars in Early Visual Cortex

## Details

**Authors** O'Bryan et al.

**Year** 2023

**Publisher** The Journal of Neuroscience

**Discipline** Neuroscience

[Read it at the publisher](https://doi.org/10.1523/JNEUROSCI.1039-23.2023) 
10.1523/JNEUROSCI.1039-23.2023

## In authors' words

### Abstract

Category learning and visual perception are fundamentally interactive processes, such that successful categorization often depends on the ability to make fine visual discriminations between stimuli that vary on continuously valued dimensions. Research suggests that category learning can improve perceptual discrimination along the stimulus dimensions that predict category membership and that these perceptual enhancements are a byproduct of functional plasticity in the visual system. However, the precise mechanisms underlying learning-dependent sensory modulation in categorization are not well understood. We hypothesized that category learning leads to a representational sharpening of underlying sensory populations tuned to values at or near the category boundary. Furthermore, such sharpening should occur largely during active learning of new categories. These hypotheses were tested using fMRI and a theoretically constrained model of vision to quantify changes in the shape of orientation representations while human adult subjects learned to categorize physically identical stimuli based on either an orientation rule ( N = 12) or an orthogonal spatial frequency rule ( N = 13). Consistent with our predictions, modeling results revealed relatively enhanced reconstructed representations of stimulus orientation in visual cortex (V1–V3) only for orientation rule learners. Moreover, these reconstructed representations varied as a function of distance from the category boundary, such that representations for challenging stimuli near the boundary were significantly sharper than those for stimuli at the category centers. These results support an efficient model of plasticity wherein only the sensory populations tuned to the most behaviorally relevant regions of feature space are enhanced during category learning.

### What they set out to do (purpose)

To test whether category learning warps early visual cortex representations and where along the continuum the enhancement concentrates.

### What they found (results)

Using fMRI orientation reconstruction in V1–V3, category learning enhanced sensory representations specifically for exemplars adjacent to the learned category boundary, not across the whole feature space.

## Commentary

### In short

Learning a category sharpens the brain's representation of stimuli right at the identity/other boundary.

### In more detail

Learning a category sharpens the neural representation of stimuli sitting right at the identity/other boundary on a feature continuum. Purpose: To test whether category learning warps early visual cortex representations and where along the continuum the enhancement concentrates. Finding: Using fMRI orientation reconstruction in V1–V3, category learning enhanced sensory representations specifically for exemplars adjacent to the learned category boundary, not across the whole feature space. [Added 2026-07-30 as new evidence beyond the original 109. DSRP structural basis: D (Definition of Distinction): plasticity targeted at the identity/other boundary drawn on a perceptual continuum.]

**Patterns it shows** D

**Added** 2026-07-30

**How to cite this** O'Bryan et al. (2023). Category Learning Selectively Enhances Representations of Boundary-Adjacent Exemplars in Early Visual Cortex. The Journal of Neuroscience.