The flexible contribution of cortical area V4 to visual perception

Cortical area V4 is thought to be critical for visual object recognition. It contains millimeter-scale domains in which neurons are highly selective for stimulus features such as shape, motion, and color. In theory, many different stimuli can be decoded from neural activity in each of these domains, but whether the brain actually makes use of this information is unknown. Here we have tested this hypothesis, using reversible inactivation of V4 in non-human primates performing a shape discrimination task. We find that training with the stimuli preferred by a particular domain causes the brain to develop a simple readout that ignores much of the information in the V4 neural population. In contrast, training with other stimuli leads to a more distributed readout of the V4 population. Thus, specialized cortical domains do not necessarily have a fixed behavioral function, but they can powerfully influence the learning of new perceptual tasks.