We investigated age-related reductions in episodic metamemory accuracy. Participants studied pictures and words in different colors, and then took forced-choice recollection tests. These tests required recollection of the earlier presentation color, holding familiarity of the response options constant. Metamemory accuracy was assessed for each participant by comparing recollection test accuracy to corresponding confidence judgments. We found that recollection test accuracy was greater in younger than older adults, and also for pictures than font color. Metamemory accuracy tracked each of these recollection differences, as well as individual differences in recollection test accuracy within each age group, suggesting that recollection ability affects metamemory accuracy. Critically, the age-related impairment in metamemory accuracy persisted even when the groups were matched on recollection test accuracy, suggesting that metamemory declines were not entirely due to differences in recollection frequency or quantity, but that differences in recollection quality and/or monitoring also played a role. We also found that age-related impairments in recollection and metamemory accuracy were equivalent for pictures and font colors. This result contrasted with previous false recognition findings, which predicted that older adults would be differentially impaired when monitoring memory for less distinctive memories. These and other results suggest that age-related reductions in metamemory accuracy are not entirely attributable to false recognition effects, but also depend heavily on deficient recollection and/or monitoring of specific details associated with studied stimuli.

Current theories of cognitive aging emphasize that the prefrontal cortex might not only be a major source of dysfunction but also a source of compensation. We evaluated neural activity associated with retrieval monitoring--or the selection and evaluation of recollected information during memory retrieval--for evidence of dysfunction or compensation. Younger and older adults studied pictures and words and were subsequently given criterial recollection tests during event-related functional magnetic resonance imaging. Although memory accuracy was greater on the picture test than the word test in both groups, activity in right dorsolateral prefrontal cortex (DLPFC) was associated with greater retrieval monitoring demands (word test > picture test) only in younger adults. Similarly, DLPFC activity was consistently associated with greater item difficulty (studied > nonstudied) only in younger adults. Older adults instead exhibited high levels of DLPFC activity for all of these conditions, and activity was greater than younger adults even when test performance was naturally matched across the groups (picture test). Correlations also differed between DLPFC activity and test performance across the groups. Collectively, these findings are more consistent with accounts of DLPFC dysfunction than compensation, suggesting that aging disrupts the otherwise beneficial coupling between DLPFC recruitment and retrieval monitoring demands.

Alzheimer’s Disease (AD) can impair metacognition in addition to more basic cognitive functions like memory. However, while global metacognitive inaccuracies are well documented (i.e., low deficit awareness, or anosognosia), the evidence is mixed regarding the effects of AD on local or task-based metacognitive judgments. Here we investigated local metacognition with respect to the confidence-accuracy relationship in episodic memory (i.e., metamemory). AD and control participants studied pictures of common objects and their verbal labels, and then took forced-choice picture recollection tests using the verbal labels as retrieval cues. We found that item-based confidence judgments discriminated between accurate and inaccurate recollection responses in both groups, implicating relatively spared metamemory in AD. By contrast, there was evidence for global metacognitive deficiencies, as AD participants underestimated the severity of their everyday problems compared to an informant’s assessment. Within the AD group, individual differences in global metacognition were related to recollection accuracy, and global metacognition for everyday memory problems was related to task-based metacognitive accuracy. These findings suggest that AD can spare the confidence-accuracy relationship in recollection tasks, and that global and local metacognition measures tap overlapping neuropsychological processes.

Alzheimer's Disease (AD) can reduce the effects of emotional content on memory for studied pictures, but less is known about false memory. In healthy adults, emotionally arousing pictures can be more susceptible to false memory effects than neutral pictures, potentially because emotional pictures share conceptual similarities that cause memory confusions. We investigatedthese effects in AD patients and healthy controls. Participants studied pictures and their verbal labels, and then picture recollection was tested using verbal labels as retrieval cues. Some of the test labels had been associated with a picture at study, whereas other had not. On this picture recollection test, we found that both AD patients and controlsincorrectly endorsed some of the test labels that had not been studiedwith pictures. These errors were associated with medium to high levels of confidence, indicating some degree of false recollection. Critically, these false recollection judgments were greater for emotionalcompared to neutral items, especially for positively valenced items, in both AD patients and controls. Dysfunction of the amygdala and hippocampusin early AD may impairrecollection, but ADdid not disrupt the effect of emotion on false recollection judgments.

Exposing older adults to ageing stereotypes can reduce their memory for studied information--a phenomenon attributed to stereotype threat--but little is known about stereotype effects on false memory. Here, we assessed ageing stereotype effects on the Deese-Roediger-McDermott false memory illusion. Older adults studied lists of semantically associated words, and then read a passage about age-related memory decline (threat condition) or an age-neutral passage (control condition). They then took a surprise memory test with a warning to avoid false recognition of non-studied associates. Relative to the control condition, activating stereotype threat reduced the recognition of both studied and non-studied words, implicating a conservative criterion shift for associated test words. These results indicate that stereotype threat can reduce false memory, and they help to clarify mixed results from prior ageing research. Consistent with the regulatory focus hypothesis, threat motivates older adults to respond more conservatively when error-prevention is emphasised at retrieval.