Aging effects on memory encoding in the frontal lobes.

Functional magnetic resonance imaging (fMRI) was used to compare frontal-lobe activation in younger and older adults during encoding of words into memory. Participants made semantic or nonsemantic judgements about words. Younger adults exhibited greater activation for semantic relative to nonsemantic judgements in several regions, with the largest activation in the left inferior frontal gyrus. Older adults exhibited greater activation for semantic judgments in the same regions, but the extent of activation was reduced in left prefrontal regions. In older adults, there was a significant association between behavioral tests of declarative and working memory and extent of frontal activation. These results suggest that age-associated decreases in memory ability may be due to decreased frontal-lobe contributions to the initial encoding of experience. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory dysfunction in multiple sclerosis: Its relation to working memory, semantic encoding, and implicit learning.

Memory disturbance is common in patients with multiple sclerosis (MS), as previously demonstrated on clinical memory tests of explicit learning using effortful retrieval paradigms. To better understand the mechanisms underlying memory failure, the authors compared the performance of 46 MS patients and 47 demographically matched normal controls on experimental tests of working memory, semantic encoding, and implicit memory. On the working memory task, MS patients demonstrated an exaggerated word length effect, which indicates a deficit in the control process of articulatory rehearsal. In contrast, MS patients demonstrated a normal buildup and release from proactive inhibition, which suggests intact semantic encoding. Finally, on priming and procedural memory tasks, MS patients performed without difficulty. The MS patients' test performance was not correlated with illness duration or course, severity of physical disability, or psychoactive medication use. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging, source memory, and misrecollections.

The authors propose an illusory recollection account of why cognitive aging is associated with episodic memory deficits. After listening to statements presented by either a female or a male speaker, older adults were prone to misrecollecting past events. The authors' illusory recollection account is instantiated in a new illusory recollection signal detection model that provides a better fit of older adults' data than does the standard signal detection model. They observed that age-related differences in source memory (as measured by source d′ scores) virtually disappear after accounting for the occurrence of illusory recollections. These data suggest that age-related source memory impairments are not due to older adults' remembering less diagnostic source information and having to guess more. Instead, older adults appear to misremember past events more often than younger adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging, source memory, and emotion.

In 2 experiments we assessed younger and older adults' ability to remember contextual information about an event. Each experiment examined memory for 3 different types of contextual information: (a) perceptual information (e.g., location of an item); (b) conceptual, nonemotional information (e.g., quality of an item); and (c) conceptual, emotional information (e.g., safety of an item). Consistent with a large literature on aging and source memory, younger adults outperformed older adults when the contextual information was perceptual in nature and when it was conceptual, but not emotional. Age differences in source memory were eliminated, however, when participants recalled emotional source information. These findings suggest that emotional information differentially engages older adults, possibly evoking enhanced elaborations and associations. The data are also consistent with a growing literature, suggesting that emotional processing remains stable with age (e.g., Carstensen & Turk-Charles, 1994, 1998; Isaacowitz, Charles, & Carstensen, 2000). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory and Aging in Context.

Much research has indicated that aging is accompanied by decrements in memory performance across a wide variety of tasks and situations. A dominant perspective is that these age differences reflect normative changes in the integrity and efficiency of the information-processing system. Contextual perspectives of development, however, argue for consideration of a broader constellation of factors as determinants of both intraindividual change and interindividual variation in memory functioning. The validity of the contextual perspective in characterizing the relationship between aging and memory is examined through a review of studies exploring a variety of alternative mechanisms associated with age differences in performance. It is concluded that a more multidimensional approach to the study of aging and memory is warranted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and prospective memory: The influence of increased task demands at encoding and retrieval.

A feature of prospective memory tasks is that they tend to be embedded into other background activities. Two experiments examined how the demands of these background activities affect age differences in prospective memory. The first experiment showed that increasing the demands of the background activities (by adding a digit-monitoring task) significantly reduced prospective memory performance. Planned comparisons revealed that age differences in prospective memory were reliable only in the more demanding background condition. The second experiment revealed significant prospective memory declines when the demands were selectively increased at encoding for both younger and older adults. When the demands were selectively increased at retrieval, older adults were particularly affected. The authors propose a model that relies on both automatic retrieval processes and working memory resources to explain prospective memory remembering. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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 false memory in the DRM paradigm: Effects of amnesia, encoding instructions, and encoding duration.

Recent studies with the Deese/Roediger–McDermott (Deese 1959; Roediger & McDermott, 1995) paradigm have revealed that amnesic patients do not only show impaired veridical memory, but also diminished false memory for semantically related lure words. Due to the typically used explicit retrieval instructions, however, this finding may reflect problems at encoding, at recollection, or both. Therefore, the present experiments examined implicit as well as explicit false memory in patients suffering from Korsakoff’s syndrome and controls. In Experiment 1, encoding instructions either focused on remembering individual list words, or on discovering semantic relationships among the words. In Experiment 2, different presentation durations were used. Results emphasize the distinction between automatic and intentional retrieval: Korsakoff patients’ veridical and false memory scores were diminished when explicit recollection was required, but not when memory was tested implicitly. Encoding manipulations only significantly affected veridical memory: Priming was reduced with thematic encoding, and explicit retrieval was facilitated when given more study time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Levels of processing, encoding specificity, elaboration, and CHARM.

[Correction Notice: An erratum for this article was reported in Vol 92(4) of Psychological Review (see record 2008-10981-001). Equation 5 on page 11 was incorrect. The correct equation is given in the erratum.] A model of cued recall called CHARM (composite holographic associative recall model) is applied to several issues that have been investigated within the depth-of-processing framework. It is shown that, given some straightforward, empirically testable assumptions about the representations of the to-be-remembered items themselves, CHARM can account for the main effect of depth of processing, the problem of the negatives, encoding–specificity interactions, and both facilitative and inhibitory effects of elaboration. The CHARM model is extended to encompass some depth-of-processing effects found in recognition memory. The highly interactive associative, storage, and retrieval mechanisms in the CHARM model are discussed. (90 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory for the Rey-Osterrieth Figure: Perceptual clustering, encoding, and storage.

Administered copy, immediate recall, and delayed recall conditions of the Rey-Osterrieth Complex Figure (ROCF) test to 50 neuropsychiatric patients (aged 23–83 yrs). Measures of copy accuracy, perceptual clustering, encoding, and savings were computed. Perceptual clustering in the copy condition was a better predictor of memory performance than was copy accuracy. An absence of association between the encoding score and the savings score suggests that these indices reflect different cognitive processes. The need to assess both immediate and delayed recall of the ROCF is emphasized. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging, memory load, and resource allocation during reading.

To test the notion that aging brings an inability to self-initiate processing, the authors investigated the effects of memory load on online sentence understanding. Younger and older adults read a series of short passages with or without a simultaneous updating task, which would be expected to deplete resources by consuming memory capacity. Regression analyses of word-by-word reading times onto text variables within each condition were used to decompose reading times into resources allocated to the array of word-level and textbase-level processes needed for comprehension. Among neither the young nor the old were word-level processes disrupted by a simultaneous memory load. However, older readers showed relatively greater levels of resource allocation to conceptual integration than the younger adults when under load, regardless of working-memory span or task priority. These results suggest that the ability to self-initiate the allocation of processing resources during reading is preserved among older readers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging Effects in Copper-Based Shape Memory Alloys

Aging of three copper-based shape memory alloys was studied by measuring the time dependence of hardness, martensitic transformation temperatures, lattice parameters, and shape memory capability at temperatures in the range 200 to 450°C. The ultimate loss of the shape memory effect in each alloy was preceded by changes in the other properties which resulted from thermally activated processes having activation energies in the range 60 to 80 kJ mol^-1. At temperatures above about 300°C the aging process involved the eventual formation of α and γ₂ phases. Although the activation energy appears to be insensitive to temperature and alloy composition, at lower temperatures other thermally activated processes, such as change in the type or degree of order, may, at least in the initial stages, be significant aging phenomena.     

Memory, amnesia, and the issue of recovered memory: neurobiological aspects

The main thesis of this article is that the debate about the credibility of "recovered memories"--reports by adults of recovered memories of childhood sexual abuse and trauma that were allegedly repressed for many years--can be usefully informed by considering the biological and behavioral facts and ideas about how memory works. Accordingly, the first section of this review describes current facts and ideas about the neurobiology and neuropsychology of memory and amnesia, including what parts of the brain are important for memory, distinctions between different memory systems in the brain, and the phenomena of infantile amnesia and source amnesia. The second section takes into account the information about the biological and behavioral bases of memory and addresses two questions about memory that have become a focus of debate in the recovered memory controversy, that is, whether memories for traumatic events change over time, and whether memories can be created for traumatic events that did not actually happen.     

The effects of perceptual interference at encoding on implicit memory, explicit memory, and memory for source.

lnterfering with stimulus identification can enhance later explicit memory performance. This counterintuitive (and theoretically unexpected) phenomenon was investigated in 5 exps. Perceptual interference enhanced category-cued recall (a conceptually driven explicit test) but had no effect on a comparable implicit memory test, category-exemplar production. This dissociation was obtained across higher levels of priming and with high-frequency as well as low-frequency exemplars. Furthermore, although perceptual interference enhanced old-new recognition memory, it did not enhance rhyme recognition (a data-driven explicit test) or source discriminability. Explanations based on enhanced semantic elaboration or enhanced encoding of spatio-temporal context do not account for the perceptual-interference effect. An account based on compensatory processing of higher level perceptual representations remains viable and is discussed in terms of the transfer-appropriate processing framework and the item-specific-relational distinction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Subjective memory complaints, psychological distress, and longitudinal change in objective memory performance.

Between 1992 and 1993, the Memory Function Questionnaire General Frequency of Forgetting Scale (MFQ-GEN), the Symptom Checklist-90—Revised General Severity Index (GSI), and Mayo Cognitive Factor Scales Learning and Retention (MCFS-LRN and MCFS-RET) current and change scores were obtained for 294 of 397 (74% ) participants, ages 55–97 years, originally assessed in a 1988–1990 normative study. In multiple regression modeling, the GSI and MCFS-LRN current score contributed 20% and 3%, respectively, to MFQ-GEN variance. Thus, emotional status was a better predictor of subjective memory ratings than either absolute objective memory performance or objective longitudinal memory change. Persons who developed cognitive impairment over the longitudinal interval reported greater memory problems, but memory complaints had little sensitivity in identifying these persons. In an approximate census sample of these older people, minor memory problems were reported to be frequent but not serious. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and interference in verbal working memory.

According to inhibitory views of working memory, old adults should have particular problems deleting irrelevant information from working memory, leading to greater interference effects compared with young adults. The authors investigated this hypothesis by using variations of an A-B, C-D retroactive interference paradigm in working memory with young and old adults. They used a recognition measure of memory, assessing both accuracy and reaction time. The primary finding was that senior adults consistently exhibited proportionally greater retroactive interference effects compared with young adults when interfering word pairs that had been read aloud had to be rejected. Patterns of recognition and reaction time data suggested that old adults' activation of target material is similar to young adults, but they experience sustained activation of irrelevation material that has entered working memory. Theoretical implications of these findings for inhibitory deficit (R.T. Zacks & L. Hasher, 1998) and source memory deficit accounts of cognitive aging are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging and fluency-based illusions in recognition memory.

We examined age-related differences in susceptibility to fluency-based memory illusions. The results from 2 experiments, in which 2 different methods were used to enhance the fluency of recognition test items, revealed that older and young adults did not differ significantly in terms of their overall susceptibility to this type of memory illusion. Older and young adults were also similar in that perceptual fluency did not influence recognition memory responses when there was a mismatch in the sensory modality of the study and test phases. Likewise, a more conceptual fluency manipulation influenced recognition memory responses in both older and young adults regardless of the match in modality. Overall, the results indicate that older adults may not be more vulnerable than young adults to fluency-based illusions of recognition memory. Moreover, young and older adults appear to be comparable in their sensitivity to factors that modulate the influence of fluency on recognition decisions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory integration and memory interference.

S. D. Moesser (see PA, Vol 56:3437; 1977) found that Ss presented with a nonsequential order of interrelating sentences did not show any evidence of having integrated these sentences into composite units. This type of presentation procedure also produces an interference effect that lessens the probability of retrieving information from the presented sentences. However, J. Bransford and J. Franks (see record 1972-24191-001) reported that Ss presented with a nonsequential order of interrelating sentences automatically integrate the partial ideas into holistic units. Bransford and Franks based their conclusions on the facts that (1) Ss were unable to identify the exact exemplars that were presented, and (2) Ss showed a bias in choosing more complex sentences as having been part of the acquisition corpus. Two experiments are reported here, which were conducted with 124 Newfoundland college students who participated in 1 of 2 encoding conditions while performing forced-choice or confidence recognition tasks. Results show that both the failure to identify presented exemplars and the tendency to choose more complex sentences in the test corpus were products of the retrieval interference effect. Findings fail to support the proposal that Ss will automatically integrate related ideas into composite units. (French abstract) (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory complaint and memory performance in the depressed elderly.

Compared depressed and nondepressed elderly Ss recruited in the context of a large epidemiological study of health on measures of self-reported memory disturbance and an objective index of memory performance (free recall). Three groups were studied: (a) 26 Ss (mean age 71.56 yrs) meeting Research Diagnostic Criteria (RDC) for major depression, (b) 25 Ss (mean age 72.16 yrs) with high levels of self-reported depressive symptoms who did not meet RDC for major depression, and (c) 26 Ss (mean age 71.81 yrs) with low levels of self-reported depressive symptoms. Ss with high depression symptom levels reported significantly higher levels of memory complaint than did Ss with low symptom levels, but there were no differences in self-reported memory disturbance as a function of depression diagnosis. There were no significant differences between groups on the free-recall measure, either as a function of symptom level or diagnosis. It is argued that symptom severity rather than diagnosis of depression is important in determining impairment in depressed elderly people. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)