Studies of the cognitive abnormalities that underlie positive symptoms in acute schizophrenia, and animal experiments that attempt to model similar cognitive abnormalities and to elucidate the brain mechanisms underlying them, suggest that the release of dopamine from A 10 terminals in the nucleus (n.) accumbens, in interaction with the projection to n. accumbens from the retrohippocampal region, is closely related to stimulus salience and perhaps to the heightened states of awareness reported by schizophrenics.