Inactivation of primate area V4 reveals inductive biases in visual learning

In primates, visual object recognition is supported in part by cortical area V4. This area is organized into millimeter-scale domains that represent specific stimulus features, such as shape, motion, and color. However, little is known about how the brain reads out this information to support behavior. We therefore trained non-human primates to perform a shape discrimination task and reversibly inactivated small patches of V4. We found that inactivation primarily impaired performance for the stimuli that yielded the strongest neural responses in the targeted domain. Effects on non-preferred stimuli were minimal, even though the identity of these stimuli could be readily decoded from neural activity. This suggested a suboptimal readout of stimulus information, and indeed, training the animals on different tasks revealed a strong inductive bias for simple readouts that could be learned efficiently. Thus, V4 domains shape the learning of perceptual tasks that involve their preferred stimuli.