Aging, episodic memory feeling-of-knowing, and frontal functioning.

Groups of normal old and young adults made episodic memory feeling-of-knowing (FOK) judgments and took 2 types of episodic memory tests (cued recall and recognition). Neuropsychological tests of executive and memory functions thought to respectively involve the frontal and medial temporal structures were also administered. Age differences were observed on the episodic memory measures and on all neuropsychological tests. Compared with young adults, older adults performed at chance level on FOK accuracy judgments. Partial correlations indicated that a composite measure of frontal functioning and FOK accuracy were closely related. Hierarchical regression analyses showed that the composite frontal functioning score accounted for a large proportion of the age-related variance in FOK accuracy. This finding supports the idea that the age-related decline in episodic memory FOK accuracy is mainly the result of executive or frontal limitations associated with aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit and explicit memory in young and older adults.

In three experiments, young and older adults were compared on both implicit and explicit memory tasks. The size of repetition priming effects in word completion and in perceptual identification tasks did not differ reliably across ages. However, age-related decrements in performance were obtained in free recall, cued recall, and recognition. These results, similar to those observed in amnesics, suggest that older adults are impaired on tasks which require conscious recollection but that memory which depends on automatic activation processes is relatively unaffected by age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging, metamemory, and high-confidence errors: A misrecollection account.

Two experiments showed that older adults were worse than younger adults at judging the accuracy of their responses on source identification (i.e., who said what) and cued-recall tests. It is important to note that this age-related metamonitoring impairment occurred even after older and younger adults were matched on overall source accuracy and cued-recall accuracy. By contrast, older and younger adults showed comparable metamonitoring capacities when assessing the likely accuracy of old-new recognition judgments and responses to questions about general knowledge. These experiments are consistent with the misrecollection account of cognitive aging, which suggests that age-related memory impairments are due to older adults' vulnerability to making high-confidence errors when answering questions that require memory for specific details about recently learned events. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Data-driven and conceptually driven processes in partial-word identification and recognition.

Three experiments examined priming in partial-word identification (Warrington & Weiskrantz, 1968) and its relation to recognition memory. The results showed that changes in modality of presentation between study and test reduced performance on both identification and recognition. In contrast, changes in elaborative processing enhanced recognition but had no effect on identification. Furthermore, when explicit memory instructions were given, identification was changed to a cued recall test and was consequently affected by elaborative processing. We also found that the time course of forgetting in priming was different from that in recognition; priming in identification did not change over a 24-hr interval, whereas recognition declined rapidly during this interval. Overall, these results suggest that identification relies primarily on data-driven processing, whereas recognition can rely on both data-driven and conceptually driven processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and memory for action events: The role of familiarity.

Two experiments with young and elderly adults explored age-related memory differences for performed action events varying in familiarity. Memory for similar items encoded verbally was also assessed. The findings demonstrated that type of encoding and item-familiarity influenced immediate as well as delayed free recall in both age groups. Highest recall performances were found for familiar performed items. Both factors affected memory performance separately and did not compensate for each other, either in immediate or in delayed free recall. These findings held true regardless of age. Performed actions were especially resistant against forgetting, indicating that, besides the amount of items encoded, performing while encoding especially enhances the retention of knowledge. Recognition memory also varied with type of encoding. Age-related memory differences were found in all free recall tests irrespective of item familiarity and type of encoding, favoring young adults. No age-related memory differences were found in the recognition test. Because of possible ceiling effects, this finding must be treated with care. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory for odors and odor names: Modalities of elaboration and imagery.

This study examined memory for common odors and odor names that were encoded with visual, verbal, and olfactory elaborations. In the first experiment, subjects elaborated olfactory stimuli by processing a picture of the odor's source, a name for the odor, or both. Two control groups were also included: One group was presented only with the odors, and another group was presented only with odor names. One week later, all subjects were given both a free recall test of odor names and an olfactory recognition test. In general, the elaboration groups outperformed the control groups, with the visual and verbal elaboration group demonstrating the best performance. In a second experiment, olfactory imaginal encoding of odor names was compared with visual imaginal encoding of the same names to measure the relative efficacy of same versus different modality encoding on later stimulus recognition. The results showed that olfactory imaginal encoding aided later recognition of odors, and visual imaginal encoding aided later picture recognition. It is suggested that different modalities contribute unique and mnemonically independent information to episodic memory performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related deficits in component processes of working memory.

Working memory deficits in normal aging have been well documented, and studies suggest that high memory load plus the presence of distraction negatively impacts successful memory performance to a greater degree in older individuals. However, characterization of the component processes that are impaired by these task manipulations is not clear. In this behavioral study, younger and older subjects were tested with a delayed-recognition and recall task in which the encoding and delay period were both manipulated. During the encoding period, the subjects were presented with either a single letter or multiple letters at their predetermined forward letter span, and the delay period was either uninterrupted or interrupted with a visual distraction. There was an age-related impairment of working memory recognition accuracy only in the combination of high memory load and distraction. These results suggest that when working memory maintenance systems are taxed, faulty recognition processes may underlie cognitive aging deficits in healthy older individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of orienting tasks on the recall and recognition performance of subjects differing in age.

Investigated the recall and recognition performance of 498 adults in 3 age groups (20–39, 40–59, and 60–80 yrs) following different orienting-task requirements. It was demonstrated that young and old adults are differentially affected by task requirements. The youngest group was disproportionately benefited by an orienting task that involved semantic processing. Results support the notion of an age-related processing deficit. (3 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Odor identification in normal aging and early Alzheimer's disease: Effects of retrieval support.

Odor sensitivity and identification were examined in normal aging and early Alzheimer's disease (AD). The aims were to investigate AD as associated with lower odor sensitivity, odor identification as a function of retrieval support, and the relationship between global cognitive functioning (Mini-Mental State Exam [MMSE]; M. R Folstein, S. E. Folstein, & P. R. McHugh, 1975) and olfactory performance. Results indicated intact odor sensitivity but deficient odor identification in AD. Both groups benefited from cues in identification, and the size of the gains was equally large in AD patients and controls. The finding of no selective benefit from retrieval support in AD suggests that a degradation of olfactory knowledge contributes to the odor identification deficits in these patients. MMSE and identification were positively related, whereas MMSE and olfactory sensitivity were unrelated. These findings suggest that the AD-related olfactory impairment stems from lesions in cortical rather than peripheral structures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An application of prefrontal cortex function theory to cognitive aging.

The purpose of this review is to extend the existing application of the frontal lobe hypothesis of cognitive aging beyond the limited work on inhibitory control (F. N. Dempster, see record 1992-22951-001) to include memory processes supported by the prefrontal cortex. To establish a background for this analysis, I review existing models of prefrontal cortex function and present a synthesized model that includes a general function of temporal integration, supported by 4 specific processes: prospective memory, retrospective memory, interference control, and inhibition of prepotent responses. I found the frontal lobe hypothesis to perform well, with the exception of an inability to account for age-related declines in item recall and recognition memory, possibly a result of age-related declines in medial temporal function. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of aging and IQ on item and associative memory.

The effects of aging and IQ on performance were examined in 4 memory tasks: item recognition, associative recognition, cued recall, and free recall. For item and associative recognition, accuracy and the response time (RT) distributions for correct and error responses were explained by Ratcliff's (1978) diffusion model at the level of individual participants. The values of the components of processing identified by the model for the recognition tasks, as well as accuracy for cued and free recall, were compared across levels of IQ (ranging from 85 to 140) and age (college age, 60–74 years old, and 75–90 years old). IQ had large effects on drift rate in recognition and recall performance, except for the oldest participants with some measures near floor. Drift rates in the recognition tasks, accuracy in recall, and IQ all correlated strongly. However, there was a small decline in drift rates for item recognition and a large decline for associative recognition and cued recall accuracy (70%). In contrast, there were large effects of age on boundary separation and nondecision time (which correlated across tasks) but small effects of IQ. The implications of these results for single- and dual-process models of item recognition are discussed, and it is concluded that models that deal with both RTs and accuracy are subject to many more constraints than are models that deal with only one of these measures. Overall, the results of the study show a complicated but interpretable pattern of interactions that present important targets for modeling. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Associative interference effects in recognition and recall.

The results of 3 studies testing whether associative interference occurs in recognition as it does in recall are reported. Associative interference was found as expected in cued recall, but it did not occur in recognition. Rather, in recognition, both the hit rate and the false alarm rate increased under interference conditions so that there was no net change in discrimination. The design of the recognition studies enabled the rejection of displaced backward rehearsals and variance differences in the matching strengths of interference and noninterference pairs as artifactual explanations of the results. The presence of associative interference in recall, but not in recognition, supports the distinction put forward by the global matching models of recognition that there is a fundamental difference between the memory access processes underlying recognition and recall. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differential effects of normal aging on recollection of concrete and abstract words.

Verbal memory is known to be affected by word features. Concrete words are remembered better than abstract words (concreteness effect), presumably due to the concurrent activation of image-based and/or semantic associations. Vivid remembering during recognition (recollection) has been linked to the hippocampus and is thought to be more affected by healthy aging than familiarity-based recognition. Recent evidence also implicated the hippocampus in the processing of concrete words. Based on these observations, we hypothesized age-related changes in recollection to affect concrete words more than abstract words. This prediction was tested in a cross-sectional design with three consecutive age groups (mean ages 21 years, 42 years, and 61 years). Changes in recollection, but not familiarity, across ages were significantly modulated by word concreteness. Recollection of concrete words showed a steady decline across age, while recollection of abstract words decreased only from young to middle age, leading to a reduced concreteness effect in the oldest group. These findings are consistent with the idea that changes in hippocampally mediated recollective processes during aging affect concrete words more than abstract words. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The premature aging hypothesis: Old before its time?

This study tested the hypothesis that alcoholism results in premature aging of memory functioning. It was proposed that support for the premature aging hypothesis must come from qualitative as well as quantitative similarities between younger alcoholics and older controls. The California Verbal Learning Test (CVLT) was administered to young and old alcoholics and to young and old controls. The CVLT provides measures of recall, recognition, learning strategies, and error types. Alcoholism and aging produced similar levels of immediate and delayed free recall. However, poor recognition memory and more frequent intrusion and false positive errors were associated with alcoholism but not with aging. Qualitative differences in error types between alcoholism and aging were also found. Results indicated that alcoholism and aging produce independent verbal learning decrements. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Investigating the structure and age invariance of episodic memory across the adult lifespan.

The structure of episodic memory was investigated by assessing different modalities of material (verbal, figural, and spatial) and different types of tests (recall, cued recall, and recognition). A 3-factor model that distinguished among modalities of material was found to be the best representation of memory and the verbal, figural, and spatial memory factors exhibiting construct validity. This 3-factor modality of material model also demonstrated configural, metric, and structural age invariance across a sample of adults (N = 327) between the ages of 18 and 94. There was evidence that latent constructs corresponding to recall, cued recall, and recognition could be distinguished from one another within the verbal domain but not within the figural and spatial domains. A mediation model examining the retrieval constructs was examined within the verbal domain, and there were unique age-related influences on cued recall and recall performance. This result is consistent with findings that increased age is associated with increased difficulty in retrieving information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The attentional demands of encoding and retrieval in younger and older adults: I. Evidence from divided attention costs.

Four studies examined the effects of divided attention in younger and older adults. Attention was divided at encoding or retrieval in free recall (Experiment 1), cued recall (Experiments 2 and 3), and recognition (Experiment 4). Dividing attention at encoding disrupted memory performance equally for the two age groups; by contrast, for both age groups, dividing attention at retrieval had little or no effect on memory performance. Secondary task reaction times (RTs) were slowed to a greater extent for the older adults than for the younger adults, especially at retrieval. Age-related differences in RTs costs at retrieval were largest in free recall, smaller in cued recall, and smallest in recognition. These results provide evidence for an age-related increase in the attentional demands of encoding and retrieval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differential age-related processing limitations in recall and recognition tasks.

The degree to which processing resources are responsible for age differences in performance on recall and recognition tasks was examined in this study. To examine this, a secondary task incorporating a memory component (digit preloads) was implemented during retrieval. Results revealed that older adults, relative to younger adults, exhibited greater decrements in secondary task performance as the difficulty of the secondary task increased. These age differences were greater in the recall task than in the recognition task. Hierarchical regression analyses indicated that speed accounted for the largest proportion of age-related variance in the recall task while both speed and working memory contributed to much of the secondary task variance. Results confirm the hypothesis that recall requires greater processing capacity than recognition and that older adults have greater processing-capacity limitations than younger adults. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

State-dependent learning in older and younger adults.

In this study state-dependent learning in younger and older adults was compared. State was manipulated by having participants rest or exercise for 5 min, followed by exposure to 3 learning trials of a 20-item word list. After a 20-min delay, participants engaged either in the congruent or in the incongruent activity followed by free-recall trial, cued-recall, and recognition tests. Heart rate, blood pressure, and self-report of distress measures verified that the experimental conditions influenced the participants' physiologic state, but the distracter tasks did not. There was no difference in learning that was due to initial exercise condition, but both age groups showed greater recall when state was congruent before learning and delayed recall. This replicates previous research in which consistent state-dependent learning effects in younger adults were found and supports research suggesting that older adults spontaneously use contextual information to facilitate recall. The demonstration of state-dependent learning in older adults is discussed as an example of implicit memory not affected by aging. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Normal aging and prospective memory.

We develop a laboratory paradigm for studying prospective memory and examine whether or not this type of memory is especially difficult for the elderly. In two experiments, young and old subjects were given a prospective memory test (they were asked to perform an action when a target event occurred) and three tests of retrospective memory (short-term memory, free recall, and recognition). From the perspective that aging disrupts mainly self-initiated retrieval processes, large age-related decrements in prospective memory were anticipated. However, despite showing reliable age differences on retrospective memory tests, both experiments showed no age deficits in prospective memory. Moreover, regression analyses produced no reliable relation between the prospective and retrospective memory tasks. Also, the experiments showed that external aids and unfamiliar target events benefit prospective memory performance. These results suggest some basic differences between prospective and retrospective memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impaired sensory and cognitive olfactory function in questionable Alzheimer's disease.

The possibility of olfactory function being affected at a very early stage of Alzheimer's disease (AD) was investigated by comparing patients with questionable AD with normal controls on odor and taste detection and short-term odor- and visual-recognition memory, including familiarity ratings. Taste and vision were studied for comparison. The questionable AD patients compared with the controls had higher thresholds for odor but not for taste, performed significantly poorer on recognition memory for odors and visual stimuli, and tended to be less familiar with odors but not with visual stimuli. The poor odor recognition memory was not found to be explained by poor odor sensitivity but may partly be due to poor long-term memory reflected by the familiarity ratings. Although further research is required, the findings indicate that performance on olfactory mediated tasks may contribute to early diagnosis of AD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)