PT  - JOURNAL ARTICLE
AU  - Steven Raiguel
AU  - Rufin Vogels
AU  - Santosh G. Mysore
AU  - Guy A. Orban
TI  - Learning to See the Difference Specifically Alters the Most Informative V4 Neurons
AID  - 10.1523/JNEUROSCI.0457-06.2006
DP  - 2006 Jun 14
TA  - The Journal of Neuroscience
PG  - 6589--6602
VI  - 26
IP  - 24
4099  - http://www.jneurosci.org/content/26/24/6589.short
4100  - http://www.jneurosci.org/content/26/24/6589.full
SO  - J. Neurosci.2006 Jun 14; 26
AB  - Perceptual learning is an instance of adult plasticity whereby training in a sensory (e.g., a visual task) results in neuronal changes leading to an improved ability to perform the task. Yet studies in primary visual cortex have found that changes in neuronal response properties were relatively modest. The present study examines the effects of training in an orientation discrimination task on the response properties of V4 neurons in awake rhesus monkeys. Results indicate that the changes induced in V4 are indeed larger than those in V1. Nonspecific effects of training included a decrease in response variance, and an increase in overall orientation selectivity in V4. The orientation-specific changes involved a local steepening in the orientation tuning curve around the trained orientation that selectively improved orientation discriminability at the trained orientation. Moreover, these changes were largely confined to the population of neurons whose orientation tuning was optimal for signaling small differences in orientation at the trained orientation. Finally, the modifications were restricted to the part of the tuning curve close to the trained orientation. Thus, we conclude that it is the most informative V4 neurons, those most directly involved in the discrimination, that are specifically modified by perceptual learning.