Long-term memory loss in senescent rats: neuropsychological analysis of interference and context effects

Four experiments are reported in which normal, senescent (25-27 months) and young adult (6 months) rats were tested for recall of a passive avoidance response 1 hr or several weeks after conditioning. There were no age differences at the 1-hr test, but a decrement was observed in old rats tested under standard conditions after long delays. The age-related impairment was exaggerated when additional approach training was administered in an identical apparatus between avoidance conditioning and testing. When the approach training was administered in an apparatus that contrasted markedly from the original, no age differences were observed. It was concluded that increased susceptibility to interference and contextual factors contributed to rapid forgetting in old rats, a pattern very similar to that observed previously in young adult rats with selective lesions to the hippocampus.     

Emotion's influence on memory for spatial and temporal context

Individuals report remembering emotional items vividly. It is debated whether this report reflects enhanced memory accuracy or a bias to believe emotional memories are vivid. We hypothesised emotion would enhance memory accuracy, improving memory for contextual details. The hallmark of episodic memory is that items are remembered in a spatial and temporal context, so we examined whether an item's valence (positive, negative) or arousal (high, low) would influence its ability to be remembered with those contextual details. Across two experiments, high-arousal items were remembered with spatial and temporal context more often than low-arousal items. Item valence did not influence memory for those details, although positive high-arousal items were recognised or recalled more often than negative items. These data suggest that emotion does not just bias participants to believe they have a vivid memory; rather, the arousal elicited by an event can benefit memory for some types of contextual details.     

Emotion's influence on memory for spatial and temporal context

Individuals report remembering emotional items vividly. It is debated whether this report reflects enhanced memory accuracy or a bias to believe emotional memories are vivid. We hypothesized emotion would enhance memory accuracy, improving memory for contextual details. The hallmark of episodic memory is that items are remembered in a spatial and temporal context, so we examined whether an item's valence (positive, negative) or arousal (high, low) would influence its ability to be remembered with those contextual details. Across two experiments, high-arousal items were remembered with spatial and temporal context more often than low-arousal items. Item valence did not influence memory for those details, although positive high-arousal items were recognized or recalled more often than negative items. These data suggest that emotion does not just bias participants to believe they have a vivid memory; rather, the arousal elicited by an event can benefit memory for some types of contextual details.     

Age-related differences in spatial memory: effects of structural and organizational context

The authors examined effects of structural and organizational spatial context on younger and older adults' memory for an arrangement of dollhouse furniture pieces. For half of the participants, landmark objects (Experiment 1) and a floor plan beneath the array (Experiment 2) served as structural context during study and replacement. Organizational context was varied by grouping items randomly or as 6 rooms in a prototypical house. Two study and replacement trials were given. In Experiment 1, landmark structural cues improved younger adults' performance, whereas both age groups benefited from the floor plan in Experiment 2. In both experiments, positive effects of organizational context and trial occurred. Higher order interactions further revealed that structural and organizational context effects varied in size across trials, suggesting that both age groups used spatial contextual cues more effectively with practice. Implications of these results for current views on cognitive compensation in adulthood are discussed.     

Young and older adults' use of context in spatial memory

We evaluated the hypothesis that older adults remember spatial information less well than younger adults because they use contextual information less effectively. Young and older adults studied schematic town maps on which structures were presented either simultaneously or successively and on which a network of streets was either present or absent. However, age did not interact with either contextual variable. Thus, we conclude that age differences in spatial memory do not arise from differences in the use of context.     

Age differences in prospective memory for everyday life intentions: A diary approach

The age benefit found in many naturalistic prospective memory (PM) tasks has been taken as evidence that PM performance in real life may be spared from aging. However, this conclusion lacks empirical confirmation. Hence, the aim of the present study was to examine possible age differences in the content of everyday PM intentions and their performance. Everyday PM was assessed in young and older adults using a diary approach. Results confirmed a general age benefit for real-life PM tasks. Importantly, this finding was qualified by revealing that the benefit only held true for specific types of intentions such as health and social intentions. Further, moderation analyses showed that the relationships between cognitive functioning and everyday PM were different for young and older adults. While better inhibition, short-term and long-term memory were related with successful PM performance in the young, this was not the case in the older adults. The present findings suggest that the age benefit found in naturalistic experimenter-given tasks extends to real-life PM performance, but may differ depending on the type of intention. Furthermore, cognitive functioning predicts performance in the young, but not in the older adults.     

Reduced memory for the spatial and temporal context of unpleasant words

Emotional stimuli are consistently better remembered than neutral stimuli. However, the reported effects of emotional stimuli on source memory are less consistent. In four experiments, we examined spatial and temporal source memory and free recall for emotional words previously studied in an fMRI experiment. In the fMRI experiment, the unpleasant but not the pleasant words were shown to activate the amygdala. In the experiments reported here, spatial and temporal source memory were reduced for the unpleasant words compared to pleasant and neutral words. Reduced spatial memory for unpleasant words was observed across studies that varied the specific stimuli, task conditions, and incidental versus intentional encoding instructions. Free recall was enhanced for the pleasant and unpleasant words compared to neutral words. The results demonstrate reduced source memory for unpleasant words even when item recall is enhanced. Our findings are consistent with prior reports of amygdala-mediated amnestic effects evoked by unpleasant stimuli.     

Obsessive compulsive disorder,checking, and non-verbal memory: a neuropsychological investigation

There is considerable evidence in the literature for the presence of non-verbal and praxic memory deficits in OCD. Such deficits may represent the cognitive substrate of doubt-related phenomenon such as checking. Neuropsychological tests of non-verbal memory functioning and memory for actions were administered to patients with OCD (whose predominant symptom was checking) and a group of matched healthy controls. Significant differences were found between the experimental and control groups, suggesting some memory impairment in the OCD group; however, no significant relationship was found linking neuropsychological test indices with checking. Significant relationships were found linking recognition memory problems and immediate memory for actions with general symptom severity.     

A neuropsychological study of fact memory and source amnesia

We investigated the ability of amnesic patients to learn new facts (e.g., Angel Falls is located in Venezuela) and also to remember where and when the facts were learned (i.e., source memory). To assess the susceptibility of fact and source memory to retrograde amnesia, patients prescribed electroconvulsive therapy were presented facts prior to the first treatment and were tested after their second treatment. All amnesic patients exhibited marked fact memory impairment. In addition, some amnesic patients exhibited source amnesia (i.e., they recalled a few facts but then could not remember where or when those facts had been learned). Source amnesia was unrelated to the severity of the memory deficit itself, because patients who exhibited source amnesia recalled as many facts as the patients who did not. These results show that the deficit in amnesia includes an impairment in acquiring and retaining new facts. Source amnesia can also occur, but it is dissociable from impaired recall and recognition and appears to reflect difficulty in remembering the specific context in which information is acquired. The findings are discussed in terms of their significance for how memory is organized.     

Subjective memory loss in age-associated memory impairment: Family history and neuropsychological correlates

Abstract

Empiricist and rationalist approaches to data-quality control in meta-analyses are discussed, and a compromise approach advocated by Strube and Hartmann (1983) for theoretically driven meta-analyses is applied to Laver and Burke's (1993) data sets. When older adults' response times (RTs) and semantic priming effects (SPEs) are regressed on young adults' RTs and SPEs, the slopes of the regression lines are approximately 1.5 as long as the age difference is held constant and performance is reasonably accurate. Both increases and decreases in RTs following unrelated and related primes, relative to RTs following baseline primes, were analyzed. The results, like those regarding RTs and SPEs, support the hypothesis that, compared with young adults who are 50 years younger, older adults take approximately 50% longer to process lexical information     

Analysis of the elements of attention: A neuropsychological approach

A model for conceptualizing the components or elements of attention is presented. The model substitutes for the diffuse and global concept of attention a group of four processes and links them to a putative system of cerebral structures. Data in support of the model are presented; they are derived from neuropsychological test scores obtained from two samples, the first consisting of 203 adult neuropsychiatric patients and normal control subjects, and the second, an epidemiologically-based sample of 435 elementary school children. Principal components analyses of test scores from these two populations yielded similar results: a set of independent elements of attention that are assayed by different tests. This work presents a heuristic for clinical research in which the measurement of attention is essential.     

Generation and context memory

Generation enhances memory for occurrence but may not enhance other aspects of memory. The present study further delineates the negative generation effect in context memory reported in N. W. Mulligan (2004). First, the negative generation effect occurred for perceptual attributes of the target item (its color and font) but not for extratarget aspects of context (location and background color). Second, nonvisual generation tasks with either semantic or nonsemantic generation rules (antonym and rhyme generation, respectively) produced the same pattern of results. In contrast, a visual (or data-driven) generation task (letter transposition) did not disrupt context memory for color. Third, generating nonwords produced no effect on item memory but persisted in producing a negative effect on context memory for target attributes, implying that (a) the negative generation effect in context memory is not mediated by semantic encoding, and (b) the negative effect on context memory can be dissociated from the positive effect on item memory. The results are interpreted in terms of the processing account of generation. The original, perceptual-conceptual version of this account is too narrow, but a modified processing account, based on a more generic visual versus nonvisual processing distinction, accommodates the results.     

Residential mobility and the family context: A developmental approach

The goal of this study was to examine the links between residential mobility and the family context, whether these links varied across developmental periods (early childhood, middle childhood, or adolescence), and how they were associated with children's achievement and behavioral outcomes. Longitudinal data from a diverse sample of over 1000 U.S. children were used to explore family structure (marital and employment change), process (quality of the home and maternal sensitivity and depression), and residential mobility. Results of structural equation models indicated that associations between residential mobility and family structure and process varied across developmental periods, with significant links found for family process in early childhood and structure in middle childhood and adolescence. We found evidence of indirect associations between residential mobility and children's outcomes through family process in early childhood and of a direct association with internalizing behaviors in adolescence. We provide implications for programs and policies for residentially mobile children.     

Auditory processing measures: correlation with neuropsychological measures of attention, memory, and behavior.

It has been suggested that measures of auditory processing (AP) are sensitive measures of attention resulting in the high comorbidity of auditory processing disorder (APD) and attention deficit/hyperactivity disorder (ADHD). Others have found that selected AP measures share significant variance with memory tasks. The current study investigated the relation between AP measures and various neuropsychological measures presumed to measure attention and memory in 36 children with a mean age of 7.78 years (SD=1.61) referred to an outpatient facility. Results indicate that AP measures significantly correlated with each other as well as with some measures of attention, memory, and behavior ratings. Results suggest that although AP measures include elements of both attention and memory, these measures also appear to assess processes not tapped by other measures of attention and memory. The correlation of AP measures with parent-and teacher-rated withdrawal, parent-rated somatization, conduct, and depression, as well as teacher-rated attention, anxiety, learning problems, social skills, and leadership suggest that auditory processing problems may manifest in myriad behaviors across settings. Implications for practice and future research are presented.     

Age,memory type,and the phenomenology of autobiographical memory: Findings from an Italian sample

The present research explored differences in phenomenology between two types of memories, a general self-defining memory and an earliest childhood memory. A sample of 76 Italian participants were selected and categorised into two age groups: 20–30 years and 31–40 years. The Memory Experiences Questionnaire (MEQ) was administered, taking note of latency and duration times of the narratives. Consistent with the literature, the self-defining memory differed significantly from the earliest childhood memory in terms of phenomenology, with the recency of the memory associated with more intense phenomenological experience. The self-defining memory took longer to retrieve and narrate than the earliest childhood memory. Meaningful differences also emerged between the two age groups: Participants in their 30s rated their self-defining memory as more vivid, coherent, and accessible than participants in their 20s. According to latency findings, these differences suggest an expanded period of identity consolidation for younger adults. Further applications of the MEQ should be carried out to replicate these results with other samples of young adults.     

Age and prospective memory

This paper reports an investigation into the effects of age, intelligence, and retrospective memory on performance in a prospective memory task in which subjects aged between 52 and 95 were required to telephone once a day either between two times or at an exact time. The most important influence on performance was how subjects chose to remember to make the telephone calls. The best performance was from subjects who telephoned either in conjunction with another routine event or engaged in some form of advanced planning of the daily schedule. The worst performance was from those who relied on internal cues from their own memory. Performance was intermediate from those who used external cues such as notes or diary entries. Subjects in the between condition were less likely to choose internal cues than those in the exact condition, possibly because the task appeared more difficult, and this resulted in their showing superior performance. The effect of age was influenced by the cue used. For subjects using internal cues, those who forgot were older than those who remembered, whereas for subjects using the other cues, those who forgot were younger than those who remembered. Regardless of cue, self-ratings of cognitive failures were related to performance such that those who reported more minor everyday mistakes were indeed more likely to forget to telephone. While there was some indirect effect of general intelligence on performance in the task, there was no relationship between retrospective memory scores and whether or not subjects remembered to telephone.     

Environmental context and human memory

Five experiments examined the effects of environmental context on recall and recognition. In Experiment 1, variability of input environments produced higher free recall performance than unchanged input environments. Experiment 2 showed improvements in cued recall when storage and test contexts matched, using a paradigm that unconfounded the variables of context mismatching and context change. In Experiment 3, recall of categories and recall of words within a category were better for same-context than different-context recall. In Experiment 4, subjects given identical input conditions showed strong effects of environmental context when given a free recall test, yet showed no main effects of context on a recognition test. The absence of an environmental context effect on recognition was replicated in Experiment 5, using a cued recognition task to control the semantic encodings of test words. In the discussion of these experiments, environmental context is compared with other types of context, and an attempt is made to identify the memory processes influenced by environmental context.     

A functionalistic approach to memory: theory and data

The purpose of this article is to propose a conceptual frame of reference for memory research on the basis of two recent lines of development. One such key development is that of a functional orientation of memory research focusing on processing and function rather than structure and memory entities. The other line of development concerns information storage as distributed rather than localized. A functionalistic frame of reference involving a notion of distributed storage is proposed. According to this view remembering is seen as an interaction between available cognitive capabilities and demands of the task in which the individual is remembering something. Encoding is conceived of as an interaction between "affordances" of the environment and "functional dispositions" of the individual. Retrieval is seen as a re-activation of functional dispositions. The formation of unique combinations of functional dispositions plays a crucial role in obtaining perfect recall performance. The viability of the overall conceptual framework is demonstrated in three experimental studies. The development of the design and procedure for these experiments was a second purpose of this paper, namely to outline an experimental setting which could serve as a complement to computer simulations in studying notions of distributed storage.     

Raven's matrices and working memory: A dual-task approach

The cognitive system does not just act as a mirror from the sensory input; instead, it tends to normalize this information. Given that letter processing seems to be much more specialized than digit processing in the cortex, we examined whether the regularization process occurs differently from digits to letters than from letters to digits: We employed a masked priming same/different experiment (e.g., probe, VESZED; prime, V35Z3D ; and target, VESZED). When embedded in letter strings, digits that resemble letters (e.g., 3 and 5 in V35Z3D -VESZED) tend to be encoded in a letter-like manner, whereas when embedded in digit strings, letters that resemble digits (e.g., E and S in 9ES7E2–935732) tend not to be encoded in a digit-like manner.     

Implicit,long-term spatial contextual memory

Learning and memory of novel spatial configurations aids behaviors such as visual search through an implicit process called contextual cuing (M. M. Chun & Y. Jiang, 1998). The present study provides rigorous tests of the implicit nature ofcontextual cuing. Experiment 1 used a recognition test that closely matched the learning task, confirming that memory traces of predictive spatial context were not accessible to conscious retrieval. Experiment 2 gave explicit instructions to encode visual context during learning, but learning was not improved and conscious memory remained undetectable. Experiment 3 illustrates that memory traces for spatial context may persist for at least 1 week, suggesting along-term component of contextual cuing. These experiments indicate that the learning and memory of spatial context in the contextual cuing task are indeed implicit. The results have implications for understanding the neural substrate of spatial contextual learning, which may depend on an intact medial temporal lobe system that includes the hippocampus (Mi. M. Chun & E. A. Phelps, 1999).