title: A single-system model predicts recognition memory and repetition priming in amnesia.
abstract: We challenge the claim that there are distinct neural systems for explicit and implicit memory by demonstrating that a formal single-system model predicts the pattern of recognition memory (explicit) and repetition priming (implicit) in amnesia. In the current investigation, human participants with amnesia categorized pictures of objects at study and then, at test, identified fragmented versions of studied (old) and nonstudied (new) objects (providing a measure of priming), and made a recognition memory judgment (old vs new) for each object. Numerous results in the amnesic patients were predicted in advance by the single-system model, as follows: (1) deficits in recognition memory and priming were evident relative to a control group; (2) items judged as old were identified at greater levels of fragmentation than items judged new, regardless of whether the items were actually old or new; and (3) the magnitude of the priming effect (the identification advantage for old vs new items) overall was greater than that of items judged new. Model evidence measures also favored the single-system model over two formal multiple-systems models. The findings support the single-system model, which explains the pattern of recognition and priming in amnesia primarily as a reduction in the strength of a single dimension of memory strength, rather than a selective explicit memory system deficit.
authors.affiliation: School of Psychology, Plymouth University, Plymouth PL4 8AA, United Kingdom, christopher.berry@plymouth.ac.uk.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Berry
authors.affiliation: Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, 6500 HE Nijmegen, The Netherlands, Centre of Excellence for Korsakoff and Alcohol-Related Cognitive Disorders, Vincent van Gogh Institute for Psychiatry, 5803 DN Venray, The Netherlands, Department of Medical Psychology, Radboud University Medical Center, 6500 HB Nijmegen, The Netherlands, and.
authors.forename: Roy P C
authors.initials: RP
authors.lastname: Kessels
authors.affiliation: Centre of Excellence for Korsakoff and Alcohol-Related Cognitive Disorders, Vincent van Gogh Institute for Psychiatry, 5803 DN Venray, The Netherlands.
authors.forename: Arie J
authors.initials: AJ
authors.lastname: Wester
authors.affiliation: Division of Psychology and Language Sciences, University College London, London WC1H 0AP, United Kingdom.
authors.forename: David R
authors.initials: DR
authors.lastname: Shanks
mesh_terms: D000328:Adult; D000647:Amnesia / Q000503:physiopathology / Q000523:psychology*; D005260:Female; D006801:Humans; D020915:Korsakoff Syndrome / Q000503:physiopathology / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D011930:Reaction Time; D021641:Recognition, Psychology / Q000502:physiology*; D060865:Repetition Priming / Q000502:physiology*
keywords: amnesia; computational model; long-term memory; memory systems; recognition memory; repetition priming