Metamemory in multiple sclerosis.

MS patients and age- and education-matched normal controls were administered several laboratory tests of metamemory and a questionnaire designed to measure subjects' capability to appraise their ability to remember events that might occur in everyday life. On laboratory tasks involving newly acquired information, MS patients with poor recognition memory abilities or poor performance on the Wisconsin Card Sorting Test (WCST) exhibited impairments on one test of metamemory; patients with deficits in both recognition and on the WCST showed more extensive impairments in metamemory. In contrast to their performance on tests involving newly acquired information, all groups of MS patients predicted their ability to recognize answers to general information questions that they could not recall as accurately as controls, and, like controls, they also searched their memories longer for answers to items that they believed they would recognize. In general, the results support the hypothesis that both trace-access and inferential mechanisms, which are thought to involve the prefrontal cortex, contribute to metamemory, but the nature of the memory task importantly influences the accuracy of metamemory, as well. Results from the questionnaire indicated that many MS patients with demonstrable memory deficits do not acknowledge their memory difficulties. Hence, patient self-reports about memory are likely to be unreliable sources of information for clinical purposes.