From inefficient to pop-out visual search in one week

Abstract

We investigated changes in brain activity while participants learned to perform a visual conjunction search task over eight successive days. In an event- related functional magnetic resonance imaging (fMRI) experiment, subjects searched for a red-green disk amongst many mirror-symmetric green-red distractors. Over sessions, accuracy increased and search-time decreased, indicative of perceptual learning and pop- out. This behavioral change was correlated with a decrease in neuronal activation in frontal and parietal cortex and an increase in activity in early visual areas during search. Training was specific to the target- distractor stimuli and did not transfer to other configurations. Our findings suggest that difficult visual search can be learned within a few days and that the trained skill is associated with distinct changes in activation in occipital, parietal and frontal cortex.