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If memory serves, will language? Later verbal accessibility of early memories.

Of major interest to those concerned with early mnemonic process and function is the question of whether early memories likely encoded without the benefit of language later are accessible to verbal report. In the context of a controlled laboratory study, we examined this question in children who were 16 and 20 months at the time of exposure to specific target events and who subsequently were tested for their memories of the events after a delay of either 6 or 12 months (at 22-32 months) and then again at 3 years. At the first delayed-recall test, children evidenced memory both nonverbally and verbally. Nonverbal mnemonic expression was related to age at the time of test; verbal mnemonic expression was related to verbal fluency at the time of test. At the second delayed-recall test, children evidenced continued accessibility of their early memories. Verbal mnemonic expression was related to previous mnemonic expression, both nonverbal and verbal, each of which contributed unique variance. The relevance of these findings on memory for controlled laboratory events for issues of memory for traumatic experiences is discussed.

Child, Preschool↗

Autobiographical memory in advanced multiple sclerosis: assessment of episodic and personal semantic memory across three time spans.

In order to investigate the status of remote memory the Autobiographical Memory Interview (AMI) was administered to 30 individuals with advanced multiple sclerosis (MS). In contrast to earlier studies which have shown only mild deficits in autobiographical memory in those with less physical progression of the disease, about two-thirds (60%) of the present MS sample had a deficit in autobiographical memory. The presence of such a deficit was not related to age, age of onset, duration of illness, or level of physical disability, but was related to level of general cognitive ability. Memory for episodic autobiographical incidents was more affected than for personal semantic information; a temporal gradient typical of some dementing conditions but not before demonstrated in MS, was also observed with memory for more recent events showing a significant decline.

Adult↗

Affect and memory: effects of pleasant and unpleasant odors on retrieval of happy and unhappy memories.

Interpretation of studies of induced mood and memory is complicated by the fact that mood induction procedures may elicit mood-related cognition in addition to mood per se. We used odors to produce positive and negative experiences with minimal cognitive involvement. College women recalled memories cued by neutral words while exposed to a pleasant odor, unpleasant odor, or no odor. Subjects then rated their memories as to how happy or unhappy the events recalled were at the time they occurred. Subjects in the pleasant odor condition produced a significantly greater percentage of happy memories than did subjects in the unpleasant odor condition. When subjects who did not find the odors at least moderately pleasant or unpleasant were removed from the analysis, more pronounced effects on memory were found. The results suggest that congruence between the general hedonic tone of current experience and that of material in long-term memory is sufficient to bias retrieval.

Adult↗

Memory in naturalistic and laboratory contexts: distinguishing the accuracy-oriented and quantity-oriented approaches to memory assessment.

A distinction is drawn between the quantity-oriented approach to memory that has dominated traditional laboratory research, and the accuracy-oriented approach that is emerging in the study of everyday memory. This distinction is shown to underlie some troubling confusions in the interpretation of empirical findings. In particular, the recall-recognition paradox, which involves the claimed superiority of recall over recognition memory in naturalistic settings, is shown to stem from the common confounding between memory property (quantity vs. accuracy) and 2 other variables that have not generally been distinguished--test format (production vs. selection) and report option (free vs. forced reporting). Three laboratory experiments reveal the fundamentally different roles played by report option and test format in accuracy-based and quantity-based memory research. Implications for memory assessment, metamemory, and the everyday-laboratory controversy are discussed.

Female↗

Cold shock before associative conditioning blocks memory retrieval, but cold shock after conditioning blocks memory retention in Caenorhabditis elegans.

The effects of cooling on associative learning and memory processes in Caenorhabditis elegans were investigated by giving the worms cold shock at various times before or after conditioning. A pretraining cold shock in the 30 min immediately before conditioning and a posttraining cold shock in the 30 min immediately after conditioning both disrupted learning and memory processes tested a short time after conditioning. However, if tested 3 hr after conditioning, worms given a pretraining cold shock demonstrated learned preferences, whereas worms given a posttraining cold shock still had memory deficits. These results suggest that the effects of cold shock on associative learning and memory can be dissociated into effects on memory retrieval and memory retention.

Animals↗

Emotionally charged autobiographical memories across the life span: the recall of happy, sad, traumatic, and involuntary memories.

A sample of 1,241 respondents between 20 and 93 years old were asked their age in their happiest, saddest, most traumatic, most important memory, and most recent involuntary memory. For older respondents, there was a clear bump in the 20s for the most important and happiest memories. In contrast, saddest and most traumatic memories showed a monotonically decreasing retention function. Happy involuntary memories were over twice as common as unhappy ones, and only happy involuntary memories showed a bump in the 20s. Life scripts favoring positive events in young adulthood can account for the findings. Standard accounts of the bump need to be modified, for example, by repression or reduced rehearsal of negative events due to life change or social censure.

Adult↗

Age differences in memory performance and memory ratings as measured in a sample survey.

Age differences in memory performance were studied in a probability sample of a cross-section of 1,491 adults living in the Detroit metropolitan area, with an oversample of those age 60 and older. Both a recall and a recognition measure were adapted to the survey context by querying respondents about the nature of the questions asked in an immediately preceding interview. Subjective memory assessment was also measured, using global memory ratings performed by the respondent, his or her spouse, and the interviewer. A clear, age-related decline in memory performance was found in this population sample. Subjective memory assessment also declined across age groups, but the relation was weaker. On the basis of multiple regression analyses of the recognition measure and the respondent's self-rated memory, which were judged to have the best measurement qualities, a substantial part of these age differences can be accounted for by differences in sociodemographic composition between age groups, by cognitive functioning and physical health.

Adult↗

The construction of autobiographical memories in the self-memory system.

The authors describe a model of autobiographical memory in which memories are transitory mental constructions within a self-memory system (SMS). The SMS contains an autobiographical knowledge base and current goals of the working self. Within the SMS, control processes modulate access to the knowledge base by successively shaping cues used to activate autobiographical memory knowledge structures and, in this way, form specific memories. The relation of the knowledge base to active goals is reciprocal, and the knowledge base "grounds" the goals of the working self. It is shown how this model can be used to draw together a wide range of diverse data from cognitive, social, developmental, personality, clinical, and neuropsychological autobiographical memory research.

Age Factors↗

Latent change models of adult cognition: are changes in processing speed and working memory associated with changes in episodic memory?

The authors used 6-year longitudinal data from the Victoria Longitudinal Study (VLS) to investigate individual differences in amount of episodic memory change. Latent change models revealed reliable individual differences in cognitive change. Changes in episodic memory were significantly correlated with changes in other cognitive variables, including speed and working memory. A structural equation model for the latent change scores showed that changes in speed and working memory predicted changes in episodic memory, as expected by processing resource theory. However, these effects were best modeled as being mediated by changes in induction and fact retrieval. Dissociations were detected between cross-sectional ability correlations and longitudinal changes. Shuffling the tasks used to define the Working Memory latent variable altered patterns of change correlations.

Aged↗

Goal-directed memory: the role of cognitive control in older adults' emotional memory.

The present study revealed that older adults recruit cognitive control processes to strengthen positive and diminish negative information in memory. In Experiment 1, older adults engaged in more elaborative processing when retrieving positive memories than they did when retrieving negative memories. In Experiment 2, older adults who did well on tasks involving cognitive control were more likely than those doing poorly to favor positive pictures in memory. In Experiment 3, older adults who were distracted during memory encoding no longer favored positive over negative pictures in their later recall, revealing that older adults use cognitive resources to implement emotional goals during encoding. In contrast, younger adults showed no signs of using cognitive control to make their memories more positive, indicating that, for them, emotion regulation goals are not chronically activated.

Affect↗

Models of immune memory: on the role of cross-reactive stimulation, competition, and homeostasis in maintaining immune memory.

There has been much debate on the contribution of processes such as the persistence of antigens, cross-reactive stimulation, homeostasis, competition between different lineages of lymphocytes, and the rate of cell turnover on the duration of immune memory and the maintenance of the immune repertoire. We use simple mathematical models to investigate the contributions of these various processes to the longevity of immune memory (defined as the rate of decline of the population of antigen-specific memory cells). The models we develop incorporate a large repertoire of immune cells, each lineage having distinct antigenic specificities, and describe the dynamics of the individual lineages and total population of cells. Our results suggest that, if homeostatic control regulates the total population of memory cells, then, for a wide range of parameters, immune memory will be long-lived in the absence of persistent antigen (T1/2 > 1 year). We also show that the longevity of memory in this situation will be insensitive to the relative rates of cross-reactive stimulation, the rate of turnover of immune cells, and the functional form of the term for the maintenance of homeostasis.

Animals↗

The roles of prefrontal brain regions in components of working memory: effects of memory load and individual differences.

Using an event-related functional MRI design, we explored the relative roles of dorsal and ventral prefrontal cortex (PFC) regions during specific components (Encoding, Delay, Response) of a working memory task under different memory-load conditions. In a group analysis, effects of increased memory load were observed only in dorsal PFC in the encoding period. Activity was lateralized to the right hemisphere in the high but not the low memory-load condition. Individual analyses revealed variability in activation patterns across subjects. Regression analyses indicated that one source of variability was subjects' memory retrieval rate. It was observed that dorsal PFC plays a differentially greater role in information retrieval for slower subjects, possibly because of inefficient retrieval processes or a reduced quality of mnemonic representations. This study supports the idea that dorsal and ventral PFC play different roles in component processes of working memory.

Adult↗

Acute stress enhances memory for emotional words, but impairs memory for neutral words.

This article examined effects of acute stress on memory for neutral and emotional words. Participants (n = 40) were exposed to either a psychosocial stressor or a control task, followed by a memory test. The stress hormone cortisol was measured in saliva before and after stress induction and after the memory test. Acute stress had a differential effect on memory such that recall of neutral words was impaired, whereas that of emotional words was enhanced. These effects on memory performance were not mediated by cortisol. The authors conclude that it makes little sense to speculate about memory effects and elevated levels of cortisol because such effects might depend on the valence of the material that is learned.

Adult↗

Utility of a microcomputer as an external memory aid for a memory-impaired head injury patient during in-patient rehabilitation.

Memory deficit is one of the most frequent cognitive complications encountered after brain injury. It is recognized as difficult to treat. Over the past decades, various strategies of memory remediation have been used. Among them, prosthetic devices, such as notebooks and alarms, have shown some benefit. This study describes the case of a 22-year-old man who demonstrated deficits in memory and executive function. In an in-patient rehabilitation setting, a microcomputer was introduced as an external memory aid. With this intervention, the patient demonstrated an immediate improvement in the ability to attend every therapy and ask for every medication on his schedule. This case study demonstrates the usefulness of a microcomputer as an external memory aid for a memory-impaired head injury survivor.

Adult↗

Effects of organization and working memory on age differences in memory for scene information.

We examined the effects of organization and working memory on young and older adults' scene memory. Subjects discriminated transformed pictures from unchanged study items in organized or unorganized scenes. Memory was tested independently for two types of scene transformations: (a) relocations (two objects rearranged and one moved) and (b) substitutions (one object replaced by another). Organization had similar effects on young and older adults, improving memory for relocations but not substitutions. Working memory significantly predicted scene memory, except for relocations in organized scenes, and partially mediated the observed age effects. The results are discussed in relation to the resource and environmental support views of cognitive aging.

Adult↗

Varying the importance of a prospective memory task: differential effects across time- and event-based prospective memory.

Only few studies have addressed the issue of task importance in prospective memory. Most of them, but not all, have shown that perceived task importance does improve prospective memory performance. However, there is little understanding of (1) the conditions under which importance of the prospective memory task makes a difference in performance and (2) the mechanisms by which perceived task importance has an effect on prospective memory performance. The present study reports two experiments that manipulate task importance in a time-based and an event-based prospective memory paradigm. Results show that importance has an effect on the time-based but not on the event-based task. Further analyses of the performance in the cover tasks as well as the monitoring behaviour indicate that importance improves prospective memory to the degree the task requires the strategic allocation of attentional resources.

Adult↗

Working memory and inferences: evidence from eye fixations during reading.

Eye fixations during reading were monitored to examine the relationship between individual differences in working memory capacity-as assessed by the reading span task-and inferences about predictable events. Context sentences predicting likely events, or non-predicting control sentences, were presented. They were followed by continuation sentences in which a target word represented an event to be inferred (inferential word) or an unlikely event (non-predictable word). A main effect of reading span showed that high working memory capacity was related to shorter gaze durations across sentence regions. More specific findings involved an interaction between context, target, and reading span on late processing measures and regions. Thus, for high- but not for low-span readers, the predicting condition, relative to the control condition, facilitated reanalysis of the continuation sentence that represented the inference concept. This effect was revealed by a reduction in regression-path reading time in the last region of the sentence, involving less time reading that region and fewer regressions from it. These results indicate that working memory facilitates elaborative inferences during reading, but that this occurs at late text-integration processes, rather than at early lexical-access processes.

Cognition↗

The development of visuo-spatial working memory.

Children's performance on tests of visuo-spatial working memory improves with age, although relatively little is known about why this happens. One explanation concerns the development of the ability to recode visually presented information into phonological form. This process appears to be used from around 8 years of age and is a major contributor to tasks in which stimuli can be verbally labelled. However, evidence suggests that phonological recoding cannot account for all of the age-related change in performance on visuo-spatial working memory tasks. In this review, four other mechanisms (knowledge, processing strategies, processing speed, and attentional capacity) are considered in terms of their contribution to children's visuo-spatial working memory development.

Child↗