ABSTRACT
T he concept of qualitatively different memory systems underlying human behavior has a long history (Schacter, 1987; Squire, 1987). One impetus to these ideas has been our common subjective experience: Although we can easily recollect past experiences in a conscious manner, many learned behaviors seem to occur “automatically” whenever the right set of circumstances occurs, without any need to consciously remember past instances of the same behavior. Such a distinction between “memories” and “habits” has received substantial support from neuroscience and neuropsychology since the 1960s. Studies of patients with memory disorders due to brain damage have demonstrated that these different forms of memory can be dissociated from one another, such that damage to particular brain regions can impair one form of memory while leaving the other intact.
