Perceptual representations depend on distributed neural codes for relaying the parts and properties of objects. Some mechanism is needed to 'bind' the information relating to each object and to distinguish it from others. Possible candidates include cells tuned to conjunctions of features, spatial attention, and synchronized firing across separate but interconnected areas of the brain. Deficits in neurological patients suggest a role for the parietal cortex in the binding process. Several current models combine these ideas.