Metamemory and frontal lobe function in the elderly.

Several measures were used to investigate age differences in metamemory, and to examine the relation between metamemory and frontal lobe function in the elderly. Three age groups were included in the study to address these issues: a Young Control group (18-30 yrs); a Young-Old group (60-75 yrs); and an Old-Old group (76-90 yrs). Metamemory was assessed in two ways. Subjects completed the Metamemory in Adulthood questionnaire (MIA; Dixon, Hultsch, & Hertzog, 1988), and subjects were asked to predict their performance on a variety of memory tasks that provided information both about awareness of their own memory functioning and knowledge of general memory processes. The relation between frontal lobe function and metamemory was assessed by administering a number of neuropsychological tests of frontal lobe abilities, and performing statistical analyses to determine how well these frontal measures predict metamemory performance. Results of the MIA questionnaire revealed that elderly subjects view their memory abilities as declining with age, whereas young subjects perceive their memory abilities to be relatively stable. On most other questionnaire dimensions, the three age groups did not differ. Age differences in metamemory were observed on the task performance predictions component of the study. Although no age differences in predictions were found for the majority of memory tasks, the elderly subjects demonstrated a significant decline in actual memory performance, particularly on the recall tasks. Significant differences in prediction-performance relations were only found between the Old-Old group and the Young Control group, reflecting a tendency for the Old-Old to overestimate their memory abilities and the Young Controls to underestimate their abilities. All subjects appeared sensitive to the effects of various manipulations on memory, indicating equivalent knowledge of general memory processes. Regression analyses demonstrated a significant relationship between frontal lobe measures and prediction-performance relations on most of the memory tasks, suggesting that a degradation in frontal lobe function with age may play a role in altered metamemory performance. The results of this study are discussed in terms of a breakdown in metacognition associated with frontal lobe dysfunction in the elderly that prevents them from updating knowledge about their own memory functioning