Memory and awareness in a patient with multiple personality disorder

Procedural memory in dissociative identity disorder: When can inter-identity amnesia be truly established?

“…The Nissen et al (1988) study has some limitations. Similar to the Dick-Barnes et al (1987) study, only 1 patient was tested.…”

“…Six experimental studies have examined implicit memory transfer between identities, most of them focusing on inter-identity priming (Dick-Barnes, Nelson, & Aine, 1987;Eich, Macaulay, Loewenstein, & Dihle, 1997a, Eich, Macaulay, Loewenstein, & Dihle, 1997bHuntjens et al, 2002;Nissen, Ross, Willingham, Mackenzie, & Schacter, 1988;Peters et al, 1998; for a review see Dorahy, 2001). Priming studies have yielded mixed results, which Eich et al (1997a) and Nissen et al (1988) ascribed to the influence of what they called identity-specific factors at the time of encoding and retrieval.…”

“…Priming studies have yielded mixed results, which Eich et al (1997a) and Nissen et al (1988) ascribed to the influence of what they called identity-specific factors at the time of encoding and retrieval. In terms of encoding, evidence of amnesia in DID was obtained on conceptually driven tasks that make use of semantically rich materials that they argued was interpreted in different ways by different identities.…”

“…In this study, however, no information was given about the a priori reported amnesia between the participating identities, making the results inapt as a case against inter-identity amnesia. Nissen et al (1988) performed the second study on procedural memory in DID. Two identities were tested, both reporting amnesia for experiences of the other identity.…”

“…In the Nissen et al (1988) study, first one identity was given three blocks of trials in a randomsequence condition. Then, the other identity was given four blocks of trials in a 10-trial repeating sequence and a fifth block consisting of a random sequence instead of the repeating sequence.…”