Unaware learning versus preserved learning in pharmacologic amnesia: similarities and differences.
The differences between learning in lorazepam (LOR)--or scopolamine (SCOP)--induced amnesia and learning in unaware drug-free normal subjects were examined. The drugs produced impairment in free recall, but did not affect digit span or word retrieval. In a verbal version, but not a motor version, of the serial reaction time task, the subjects who received SCOP or higher dose LOR showed impairment of sequence-specific learning. Subjects who received placebo had no such impairment. In the stem completion paradigm, higher dose LOR, but not SCOP, impaired performance. In a tachistoscopic word identification task, neither drug interfered with repetition priming. Unaware learning and drug-induced amnesic learning were thus dissociable. These findings disconfirm the hypothesis that unaware learning and drug-induced amnesic learning are analogous.
Knopman
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Department of Neurology, University of Minnesota, Minneapolis.
D000293:Adolescent; D000328:Adult; D000647:Amnesia / Q000139:chemically induced / Q000523:psychology*; D005260:Female; D006801:Humans; D007858:Learning / Q000187:drug effects / Q000502:physiology*; D008140:Lorazepam / Q000097:blood / Q000494:pharmacology; D008297:Male; D011594:Psychometrics; D011930:Reaction Time; D012601:Scopolamine / Q000097:blood / Q000494:pharmacology; D013647:Task Performance and Analysis
D012601:Scopolamine; D008140:Lorazepam