Global Similarity Predicts Dissociation of Classification and Recognition: Evidence Questioning the Implicit-Explicit Learning Distinction in Amnesia

• Published in: Journal of experimental psychology. Learning, memory, and cognition memory, and cognition, 2010-11, Vol.36 (6), p.1529-1535
• Main Authors: Jamieson, Randall K, Holmes, Signy, Mewhort, D. J. K
• Format: Article
• Language: English
• Subjects: Adult and adolescent clinical studies; Amnesia; Amnesia - physiopathology; Amnesia - psychology; Biological and medical sciences; Classification; Classification (Cognitive Process); Cognition & reasoning; Disorders of higher nervous function. Focal brain diseases. Central vestibular syndrome and deafness. Brain stem syndromes; Dissociation; Experimental psychology; Explicit Memory; Foreign Countries; Fundamental and applied biological sciences. Psychology; Human; Humans; Implicit Learning; Learning; Learning - physiology; Learning. Memory; Manitoba; Medical sciences; Memory; Nervous system (semeiology, syndromes); Neurological Impairments; Neurology; Neuropsychological Tests; Organic mental disorders. Neuropsychology; Photic Stimulation - methods; Predictive Value of Tests; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psychopathology. Psychiatry; Recognition (Learning); Recognition (Psychology); Recognition (Psychology) - classification; Recognition (Psychology) - physiology; Semantics; Students; Time Factors; Undergraduate Students; Universities
• ISSN: 0278-7393; 1939-1285
• DOI: 10.1037/a0020598

Dissociation of classification and recognition in amnesia is widely taken to imply 2 functional systems: an implicit procedural-learning system that is spared in amnesia and an explicit episodic-learning system that is compromised. We argue that both tasks reflect the global similarity of probes to memory. In classification, subjects sort unstudied grammatical exemplars from lures, whereas in recognition, they sort studied grammatical exemplars from lures. Hence, global similarity is necessarily greater in recognition than in classification. Moreover, a grammatical exemplar's similarity to studied exemplars is a nonlinear function of the integrity of the data in memory. Assuming that data integrity is better for control subjects than for subjects with amnesia, the nonlinear relation combined with the advantage for recognition over classification predicts the dissociation of recognition and classification. To illustrate the dissociation of recognition and classification in healthy undergraduates, we manipulated study time to vary the integrity of the data in memory and brought the dissociation under experimental control. We argue that the dissociation reflects a general cost in memory rather than a selective impairment of separate procedural and episodic systems. (Contains 3 figures and 3 footnotes.)