Age-related differences in metacognition for memory capacity and selectivity

ABSTRACT

Background: We compared two types of metacognitive monitoring in younger and older adults: metacognitive accuracy for their overall memory performance and their ability to selectively remember high-value information. Method: Participants studied words paired with point values and were asked to maximise their point score. In Experiment 1, they predicted how many words they would remember while in Experiment 2, they predicted how many points they would earn. Results: In Experiment 1, while younger adults were accurate in their predictions, older adults were overconfident in the number of words they would recall throughout the task. In Experiment 2, however, both younger and older adults were equally accurate when predicting the amount of points they would earn after some task experience. Conclusions: While younger adults may have higher metacognitive accuracy for their capacity, older adults can accurately assess their ability to selectively remember information, suggesting potentially separate metacognitive mechanisms that are differentially affected by aging.     

Greater priming for previously distracting information in young than older adults when suppression is ruled out

The use of previously distracting information on memory tests with indirect instructions is usually age-equivalent, while young adults typically show greater explicit memory for such information. This could reflect qualitatively distinct initial processing (encoding) of distracting information by younger and older adults, but could also be caused by greater suppression of such information by younger adults on tasks with indirect instructions. In Experiment 1, young and older adults read stories containing distracting words, which they ignored, before studying a list of words containing previously distracting items for a free recall task. Half the participants were informed of the presence of previously distracting items in the study list prior to recall (direct instruction), and half were not (indirect instruction). Recall of previously distracting words was age-equivalent in the indirect condition, but young adults recalled more distracting words in the direct condition. In Experiment 2, participants performed the continuous identification with recognition task, which captures a measure of perceptual priming and recognition on each trial, and is immune to suppression. Priming and recognition of previously distracting words was greater in younger than older adults, suggesting that the young engage in more successful suppression of previously distracting information on tasks in which its relevance is not overtly signaled.     

Implicit memory for novel conceptual associations in amnesia

In two experiments, we evaluated the status of implicit memory for novel associations in amnesia. Experiment 1 assessed priming in a category exemplar generation task in which contextual information associated with a target could increase the likelihood of target generation. Control participants, but not amnesic patients, showed associative priming. Amnesics’ impairment was not due to the use of explicit memory by control subjects but reflected a genuine impairment in implicit memory for novel conceptual associations. Experiment 2 assessed priming in a relatedness judgment task, in which associative priming was manifest as longer latencies for old than for recombined pairs of unrelated words. Amnesic patients showed intact associative priming in this task. We discuss differences in the status of implicit memory for novel conceptual associations in amnesia, with reference to the nature of the representation that supports priming in the two tasks and the type of processing that is required at test.     

Generation difficulty and memory for source

The role of the word predictability from sentence context for reality monitoring and external source monitoring was examined in two experiments. In a reality-monitoring task, discrimination of an internal source was better in the hard than in the easy condition. It is probable that extra cognitive operations engaged during word generation in the hard condition were effective cues for reality-monitoring judgements. In contrast, in an external source-monitoring task (recognition memory of item's colour), the hard condition resulted in worse source memory for generated words than did the easy condition. This result is consistent both with an item-context trade-off hypothesis and a processing hypothesis. Greater effort involved at the time of generation might limit resources available for encoding of an external source. It is also possible that for generated words, the hard condition promoted conceptual processing instead of perceptual processing; therefore the item's colour was not effectively encoded.     

Does survival processing enhance implicit memory?

Recent research has shown that human memory may have evolved to remember information that has been processed for the purpose of survival, more so than information that has been processed for other purposes, such as home-moving. We investigated this survival-processing advantage using both explicit and implicit memory tests. In Experiment 1, participants rated words in one of three scenarios: survival, pleasantness, and moving, followed by a timed stem-cued recall/stem-cued completion task. Items were completed more quickly in the survival scenario, as compared with the other two for the explicit task, but no differences were found across conditions in the implicit task. In Experiment 2, the implicit task was changed to concreteness judgments to encourage more conceptual processing. Again, the survival-processing advantage occurred in the explicit task (speeded item recognition), but not in the implicit task. These results suggest that a survival-processing advantage may benefit participants’ memory performance only during explicit retrieval.     

Memory for instances and categories in children and adults

College subjects and 7-year-olds were trained in sorting 16 words into two conceptual categories. Training consisted of either three list presentations (Experiment I) or training to solution (Experiment II). Then either immediately or after a 3 to 4 week delay subjects received a recognition test which assessed memory for the instance vs categorical properties of the task stimuli by embedding words from the original list and from the list categories with confusion items from either the same or different categories as those on the original list. The data indicated that learning and memory were controlled primarily by categorical properties of the task items in adults and by specific instance properties in children. However, there was evidence that children had learned the categorical attributes of the task and may have differed from adults chiefly in their failure to utilize these attributes to assist learning and memory performance. The age differences in learning and memory were independent of the degree of initial training.     

The role of vocabulary ability during visual word recognition in younger and older adults

The role that vocabulary ability plays in adult age differences in word recognition was investigated. In Experiment 1, 44 older adults (ages 61-93 years) were compared with 44 younger adults (ages 18-39 years) on a standard lexical-decision task, with ambiguous words, unambiguous words, and pseudowords serving as stimuli. In Experiment 1, the Wechsler Adult Intelligence Scale-Revised (WAIS-R; D. Wechsler, 1981) vocabulary performance was uncontrolled across the younger and older adults, and the older adults had higher WAIS-R scores. There was no Group x Stimulus interaction. In Experiment 2, the data from the same 44 older adults were compared with data from a new sample of 44 younger adults (ages 18-44). Both groups were then matched on WAIS-R performance. Results revealed a significant Group x Stimulus interaction. Reaction time differences between the younger and older groups on the ambiguous words and unambiguous words were identical. The differences in reaction times for words and pseudowords were greater in the older adults. The importance of vocabulary ability during word recognition and lexical processing is discussed.     

Generation difficulty and memory for source

The role of the word predictability from sentence context for reality monitoring and external source monitoring was examined in two experiments. In a reality-monitoring task, discrimination of an internal source was better in the hard than in the easy condition. It is probable that extra cognitive operations engaged during word generation in the hard condition were effective cues for reality-monitoring judgements. In contrast, in an external source-monitoring task (recognition memory of item's colour), the hard condition resulted in worse source memory for generated words than did the easy condition. This result is consistent both with an item–context trade-off hypothesis and a processing hypothesis. Greater effort involved at the time of generation might limit resources available for encoding of an external source. It is also possible that for generated words, the hard condition promoted conceptual processing instead of perceptual processing; therefore the item's colour was not effectively encoded.     

Illusory recollection of voices

We investigated source misattributions in the DRM false memory paradigm (Deese, 1959, Roediger & McDermott, 1995). Subjects studied words in one of two voices, manipulated between‐lists (pure‐voice lists) or within‐list (mixed‐voice lists), and were subsequently given a recognition test with voice‐attribution judgements. Experiments 1 and 2 used visual tests. With pure‐voice lists (Experiment 1), subjects frequently attributed related lures to the corresponding study voice, despite having the option to not respond. Further, these erroneous attributions remained high with mixed‐voice lists (Experiment 2). Thus, even when their related lists were not associated with a particular voice, subjects misattributed the lures to one of the voices. Attributions for studied items were fairly accurate in both cases. Experiments 3 and 4 used auditory tests. With pure‐voice lists (Experiment 3), subjects frequently attributed related lures and studied items to the corresponding study voice, regardless of the test voice. In contrast, with mixed‐voice lists (Experiment 4), subjects frequently attributed related lures and studied items to the corresponding test voice, regardless of the study voice. These findings indicate that source attributions can be sensitive to voice information provided either at study or at test, even though this information is irrelevant for related lures.     

How does encoding context affect memory in younger and older adults?

How does encoding context affect memory? Participants studied visually presented words viewed concurrently with a rich (intact face) or weak (scrambled face) image as context and subsequently made "Remember", "Know", or "New" judgements to words presented alone. In Experiment 1a, younger, but not older, adults showed higher recollection accuracy to words from rich- than from weak-context encoding trials. The age-related deficit in recollection occurred, in Experiment 1b, even when encoding and retrieval time was doubled in older adults, suggesting that insufficient processing time cannot account for this age-related deficit. In Experiment 1c, dividing attention in young, during encoding, reduced overall memory, though the recollection boost from rich encoding contexts remained, suggesting that reduced attention resources cannot explain this age-related deficit. Experiment 2 showed that an own-age bias, to face images as context, could not explain the age-related differences either. Results suggest that age deficits in recollection stem from a lack of spontaneous binding, or elaboration, of context to target information during encoding.     

Dual-modality monitoring in a classification task: the effects of bilingualism and ageing

Two experiments are reported in which monolingual and bilingual participants who were younger (Experiment 1) or older (Experiment 2) adults performed in a dual-task classification paradigm. Visually (primary task) and auditorily (secondary task) presented stimuli were classified into two categories. The stimuli belonged to two domains, letters or numbers (LN) and animals or musical instruments (AM), and the two task modalities used stimuli from the same (related) or opposite (unrelated) domains. For both age groups, bilinguals were less disrupted than monolinguals in visual sorting in the LN domain, and relatedness affected performance only in the AM domain. The results indicate different processing demands for the two domains, with the simpler domain (LN) favouring bilinguals and the more semantically complex domain (AM) favouring related judgements for the two task modalities.     

Dual-modality monitoring in a classification task: The effects of bilingualism and ageing

Two experiments are reported in which monolingual and bilingual participants who were younger (Experiment 1) or older (Experiment 2) adults performed in a dual-task classification paradigm. Visually (primary task) and auditorily (secondary task) presented stimuli were classified into two categories. The stimuli belonged to two domains, letters or numbers (LN) and animals or musical instruments (AM), and the two task modalities used stimuli from the same (related) or opposite (unrelated) domains. For both age groups, bilinguals were less disrupted than monolinguals in visual sorting in the LN domain, and relatedness affected performance only in the AM domain. The results indicate different processing demands for the two domains, with the simpler domain (LN) favouring bilinguals and the more semantically complex domain (AM) favouring related judgements for the two task modalities.     

Illusory recollection of voices

We investigated source misattributions in the DRM false memory paradigm (Deese, 1959, Roediger & McDermott, 1995). Subjects studied words in one of two voices, manipulated between-lists (pure-voice lists) or within-list (mixed-voice lists), and were subsequently given a recognition test with voice-attribution judgements. Experiments 1 and 2 used visual tests. With pure-voice lists (Experiment 1), subjects frequently attributed related lures to the corresponding study voice, despite having the option to not respond. Further, these erroneous attributions remained high with mixed-voice lists (Experiment 2). Thus, even when their related lists were not associated with a particular voice, subjects misattributed the lures to one of the voices. Attributions for studied items were fairly accurate in both cases. Experiments 3 and 4 used auditory tests. With pure-voice lists (Experiment 3), subjects frequently attributed related lures and studied items to the corresponding study voice, regardless of the test voice. In contrast, with mixed-voice lists (Experiment 4), subjects frequently attributed related lures and studied items to the corresponding test voice, regardless of the study voice. These findings indicate that source attributions can be sensitive to voice information provided either at study or at test, even though this information is irrelevant for related lures.     

Capturing conceptual implicit memory: The time it takes to produce an association

Conceptual implicit memory is demonstrated when, in the absence of explicit retrieval, performance on a task requiring conceptual processing benefits more from prior conceptual encoding than from prior nonconceptual encoding. In the present study, we sought to provide an improved measure of conceptual implicit memory by minimizing contamination from explicit retrieval. On a modified word association test, participants free-associated to the actually studied items, with response time to produce any associate serving as the dependent measure. Experiment 1 varied whether words were read or generated at study and showed that generated words were associated to more quickly than were read words. Experiment 2 varied level of processing at study and showed that words processed semantically were associated to more quickly than were words processed nonsemantically. With modifications to ensure its implicit nature, a conceptual implicit test can be consistently affected by the same encoding manipulations as those that affect conceptual explicit memory tests.     

Perceptual specificity and implicit auditory priming in older and younger adults.

Age differences in perceptual specificity for implicit auditory priming were examined in 3 experiments. All 3 experiments began with a study phase during which participants rated words based on perceptual (shallow encoding) or semantic (deep encoding) attributes. After the study phase, participants were asked to identify filtered versions of repeated and new words (implicit test) and then to make old/new recognition judgments (explicit test). In contrast to earlier findings (D. L. Schacter, B. Church, & D. M. Osowiecki, 1994), older and younger adults were equally sensitive to study-to-test changes in speaking rate (Experiment 1), fundamental frequency (Experiment 2), and voice (Experiment 3). Explicit memory, in contrast, was significantly poorer for older adults but was minimally affected by changes in surface features. Findings from the study are discussed with respect to their implications for establishing the mechanisms mediating perceptual specificity and for their importance in understanding age-related changes in implicit memory.     

Earwitness Testimony: Never Mind the Variety,Hear the Length

Three aspects of voice recognition were investigated in the study reported here: memory for familiar voices, memory for the words spoken, and the relative effects of length and variation in a voice extract on long- and short-term memory. In Experiment 1, recognition memory for the briefly heard voice of a stranger was superior with longer extracts (p<0.01), but increasing vowel variety did not improve performance. This pattern was repeated for short-term memory (p<0.01) in Experiment 2. Scores for the above task correlated significantly (p<0.05) with scores for recognizing well-known voices. In a further test of well-known voice memory in Experiment 3, a weak and non-significant positive correlation (r=0.29) was found between memory for well-known voices and memory for a once-heard voice. Memory for the words spoken did not correlate significantly with memory for the unknown voice itself. The possibilities of a memory-for-voices general ability, and forensic applications of the findings are discussed. © 1997 by John Wiley & Sons, Ltd.     

How does encoding context affect memory in younger and older adults?

How does encoding context affect memory? Participants studied visually presented words viewed concurrently with a rich (intact face) or weak (scrambled face) image as context and subsequently made “Remember”, “Know”, or “New” judgements to words presented alone. In Experiment 1a, younger, but not older, adults showed higher recollection accuracy to words from rich- than from weak-context encoding trials. The age-related deficit in recollection occurred, in Experiment 1b, even when encoding and retrieval time was doubled in older adults, suggesting that insufficient processing time cannot account for this age-related deficit. In Experiment 1c, dividing attention in young, during encoding, reduced overall memory, though the recollection boost from rich encoding contexts remained, suggesting that reduced attention resources cannot explain this age-related deficit. Experiment 2 showed that an own-age bias, to face images as context, could not explain the age-related differences either. Results suggest that age deficits in recollection stem from a lack of spontaneous binding, or elaboration, of context to target information during encoding.     

Use of relational and item-specific information in remembering by older and younger adults

The applicability to older adults of predictions from the integrated memory model, that optimal memory results from concurrent availability of relational and item-specific information, was assessed. In Experiment 1, older adults (M = 69 years) encoded related or unrelated words using rating, sorting, or both tasks. Using both tasks produced better recall than either separate task. Rating facilitated recall for related items, but sorting did not facilitate unrelated items. In Experiment 2, younger (M = 20) and older (M = 74) adults sorted or rated lists comprising categories of varying sizes. Young adults' free recall conformed to predictions, but older adults again showed facilitation mainly from rating larger categories. The stronger effects for younger adults imply that specific combinations of encoding and retrieval manipulations and materials must be considered in predicting older adults' performance.     

Causal attributions and strategy use in relation to memory performance differences in younger and older adults

A metacognitive hypothesis to explain age differences in adult memory is explored here–that younger and older adults differ in beliefs about memory and strategic processing. The motivational beliefs that adults make for their own memory performances were examined across tests of recall, recognition, face–name learning, and appointment-keeping. Forty-eight older and 48 younger community-living adults were required to report the factors they believed influenced their performance and the memory strategies used for each task. A final questionnaire required subjects to rank order the importance of a list of causal factors. There were significantly more younger adults as compared to older adults who attributed performance to controllable factors (i.e. strategy use), although age differences in beliefs on a more familiar memory task were smaller than on other tasks. Moreover, within age groups, attributions to controllable factors were associated with increased memory performance compared to when memory was attributed to uncontrollable factors (i.e. ability, age). Believing that memory is uncontrollable may undermine the efficient use of effort in cognition, consistent with current metacognitive theory.     

提取干扰对知觉和概念启动的影响

通过学习—测验范式,分别以词汇判断、语义分类任务为测验,探讨提取干扰对不同识别式记忆的影响差异。结果发现,实验1验证了识别式知觉内隐记忆的提取干扰效应,实验2发现识别式概念内隐记忆在提取干扰下也明显降低;两个实验启动量联合分析发现,相比无干扰条件,概念启动比知觉启动受到提取干扰的破坏更大。上述结果说明识别式内隐记忆的提取干扰具有普遍性,提取干扰产生了不同识别式内隐记忆之间的分离,识别式概念内隐记忆更容易受到提取干扰的影响。