What visual perception tells us about mind and brain

Recent studies of visual perception have begun to reveal the connection bet ween neuronal activity in the brain and conscious visual experience. Transc ranial magnetic stimulation of the human occipital lobe disrupts the normal perception of objects in ways suggesting that important aspects of visual perception are based on activity in early visual cortical areas. Recordings made with microelectrodes In animals suggest that the perception of the li ghtness and depth of visual surfaces develops through computations performe d across multiple brain areas. Activity in earlier areas is more tightly co rrelated with the physical properties of objects whereas neurons in later a reas respond in a manner more similar to visual perception.