Understanding the neural correlates of visual perception: a survey of our toolbox.

One of the central goals of neuroscience is to elucidate the link between behavior and neuronal activity at both single neuron level and the level of neuronal ensembles. New analytical approaches and techniques constantly emerge that correlate neural activity with perception and behavior with ever finer temporal and spatial scales. In this article I review some of these approaches employed in studies of visual perception in which perceptual reports were required from subjects. I divide these methods into 'correlational' methods and 'perturbation' methods; the former measures normal neural activity and correlates it with behavior, the latter perturbs normal neural activity to cause behavioral alterations. I compare such approaches applied to primates with those applied to human subjects, and discuss how these approaches could be combined and made more powerful in the future.