Word frequency and word stem completion in Korsakoff patients.

Korsakoff patients are generally agreed to be impaired in conscious recollection, but whether their implicit memory performance is also affected is less certain. A deficit in novelty dependent encoding (i.e., elaboration learning) could account for both types of impairments and predicts a reduced implicit word frequency effect in the patients. This effect was examined with word stem completion in nineteen Korsakoff patients and nineteen healthy controls. The word frequency effect was larger in controls than in patients in absolute terms, but not reliably so. It is concluded that elaboration learning may be spared to some degree in Korsakoff amnesia, but, in line with the original reasoning by Korsakoff (1889/1996), it may only be engaged by the patients when they are continuously prompted to do so.