Search

Recollecting past experiences and imagining future experiences activate a common set of brain regions that includes the hippocampus (Schacter, Addis, & Buckner, 2007), and both functions are impaired in people with compromised hippocampal function (Klein, Loftus, & Kihlstrom, 2002; Tulving, 1985). These findings indicate a role for the hippocampus that extends beyond declarative memory. However, a case study revealed that a person with extensive medial temporal lobe (MTL) damage and episodic amnesia was able to forgo smaller, immediate rewards for a larger future payoff to a degree similar to control participants (Kwan et al., 2012). This finding suggests that typical regard for the future does not depend on hippocampal integrity. To test this hypothesis, the current study examined the nature and limits of the role of the hippocampus in future thinking and decision making in amnesic individuals with hippocampal damage and associated impairments in episodic memory and future imagining. The amnesic individuals were administered a delay discounting task to assess valuation of future rewards, a probability discounting task to assess risk taking, and the Zimbardo Time Perspective Inventory to assess personal orientation toward the past, present, and future. Comparisons with demographically matched controls indicated that aspects of temporal thought and future-oriented decision making are preserved in individuals with hippocampal amnesia despite their inability to imagine themselves in detailed future events. Thus, even extensive MTL damage and the resulting episodic amnesia do not preclude prudent decision making, including consideration of future financial outcomes and personal identification with the past and future., (PsycINFO Database Record (c) 2013 APA, all rights reserved.)

Two experiments compared the effects of depth of processing on working memory (WM) and long-term memory (LTM) using a levels-of-processing (LOP) span task, a newly developed WM span procedure that involves processing to-be-remembered words based on their visual, phonological, or semantic characteristics. Depth of processing had minimal effect on WM tests, yet subsequent memory for the same items on delayed tests showed the typical benefits of semantic processing. Although the difference in LOP effects demonstrates a dissociation between WM and LTM, we also found that the retrieval practice provided by recalling words on the WM task benefited long-term retention, especially for words initially recalled from supraspan lists. The latter result is consistent with the hypothesis that WM span tasks involve retrieval from secondary memory, but the LOP dissociation suggests the processes engaged by WM and LTM tests may differ. Therefore, similarities and differences between WM and LTM depend on the extent to which retrieval from secondary memory is involved and whether there is a match (or mismatch) between initial processing and subsequent retrieval, consistent with transfer-appropriate-processing theory.

The relations between higher cognitive abilities and immediate and delayed recall were studied in 57 children (6-16 years of age). The participants were tested repeatedly on free recall of a supraspan list (Children's Memory Scale), and their fluid ability was also assessed (Woodcock-Johnson III Spatial Relations). Consistent with Unsworth and Engle's (2007) account of the relation between memory and higher order cognition, the children's fluid ability was significantly correlated with retrieval from secondary memory, regardless of whether it was measured using immediate or delayed recall. Multiple regression analyses provided further support for this view, revealing that measures of immediate and delayed retrieval from secondary memory accounted for the same variance in the children's fluid ability.

It has been hypothesized that older adults are especially susceptible to proactive interference (PI) and that this may contribute to age differences in working memory performance. In young adults, individual differences in PI affect both working memory and reasoning ability, but the relations between PI, working memory, and reasoning in older adults have not been examined. In the current study, young, old, and very old adults performed a modified operation span task that induced several cycles of PI buildup and release as well as two tests of abstract reasoning ability. Age differences in working memory scores increased as PI built up, consistent with the hypothesis that older adults are more susceptible to PI, but both young and older adults showed complete release from PI. Young adults' reasoning ability was best predicted by working memory performance under high PI conditions, replicating M. Bunting (2006). In contrast, older adults' reasoning ability was best predicted by their working memory performance under low PI conditions, thereby raising questions regarding the general role of susceptibility to PI in differences in higher cognitive function among older adults., ((c) 2008 APA, all rights reserved)

The authors report 2 experiments in which they examined age differences in working memory tasks involving complex item manipulation (i.e., letter-number sequencing). In Experiment 1, age differences on tasks involving item manipulation were not greater than age differences on tasks requiring recall of items in the order in which they appeared, suggesting that older adults do not have difficulty with item manipulation per se. In Experiment 2, slower presentation rates increased age differences in item manipulation spans, although age differences at the fastest rate may be attributed to differences in strategy use. In both experiments, age differences were largest when participants were most likely to be remembering familiar sequences, suggesting that older adults may have difficulties dampening the representations of such sequences once they are activated., (((c) 2007 APA, all rights reserved).)

It has been suggested, primarily based on response time (RT) data, that there is an age-related increase in intraindividual variability. To determine whether older adults show more intraindividual variability in working memory (WM) performance, we had younger and older adults perform three verbal WM tasks of varying complexity as well as a same-different judgment RT task. For both groups, individual performance tended to be more variable on the two complex span tasks than on the simple span task. Although older adults showed greater variability on the RT task, consistent with previous studies, they did not show greater variability on any of the WM tasks. These findings fail to support theories of frontal lobe aging that predict greater moment-to-moment fluctuations in the performance of older adults.

In the present experiments, we examined whether shifts of attention selectively interfere with the maintenance of both verbal and spatial information in working memory and whether the interference produced by eye movements is due to the attention shifts that accompany them. In Experiment 1, subjects performed either a spatial or a verbal working memory task, along with a secondary task requiring fixation or a secondary task requiring shifts of attention. The results indicated that attention shifts interfered with spatial, but not with verbal, working memory, suggesting that the interference is specific to processes within the visuospatial sketchpad. In Experiment 2, subjects performed a primary spatial working memory task, along with a secondary task requiring fixation, an eye movement, or an attention shift executed in the absence of an eye movement. The results indicated that both eye movements and attention shifts interfered with spatial working memory. Eye movements interfered to a much greater extent than shifts of attention, however, suggesting that eye movements may contribute a unique source of interference, over and above the interference produced by the attention shifts that accompany them.

We investigated whether individuals who are good at recognizing previously presented items are also good at recognizing the context in which items were presented. We focused specifically on whether the relation between item recognition and context recognition abilities differs in younger and older adults. It has been hypothesized that context memory declines more rapidly in older adults due to an age-related deficit in associative binding or recollection. To test this hypothesis, younger and older adults were asked to remember lists of names and objects, as well as the context (i.e. their size, location, and color) that accompanied those items. Following presentation of each list, recognition tests for items and context were administered. Confirmatory factor analysis (CFA) models analyzing both item and context scores together provided no evidence of separate factors for item and context memory. Instead, the best-fitting model separated performance by item-type, regardless of context, and no differences were found in the structure of these abilities in younger and older adults. These findings are consistent with the limited previous latent variable research on context memory in aging suggesting that there is no context recognition memory ability separable from item memory in younger nor older adults. Instead, individual differences in recognition memory abilities may be specific to the domain of the studied stimulus. [ABSTRACT FROM AUTHOR]

In the present experiments, we examined the effects of environmental support on participants' ability to rehearse locations and the role of such support in the effects of secondary tasks on memory span. In Experiment 1, the duration of interitem intervals and the presence of environmental support for visuospatial rehearsal (i.e., the array of possible memory locations) during the interitem intervals were both manipulated across four tasks. When support was provided, memory spans increased as the interitem interval durations increased, consistent with the hypothesis that environmental support facilitates rehearsal. In contrast, when environmental support was not provided, spans decreased as the duration of the interitem intervals increased, consistent with the hypothesis that visuospatial memory representations decay when rehearsal is impeded. In Experiment 2, the ratio of interitem interval duration to intertrial interval duration was kept the same on all four tasks, in order to hold temporal distinctiveness constant, yet forgetting was still observed in the absence of environmental support, consistent with the decay hypothesis. In Experiment 3, the effects of impeding rehearsal were compared to the effects of verbal and visuospatial secondary processing tasks. Forgetting of locations was greater when presentation of to-be-remembered locations alternated with the performance of a secondary task than when rehearsal was impeded by the absence of environmental support. The greatest forgetting occurred when a secondary task required the processing visuospatial information, suggesting that in addition to decay, both domain-specific and domain-general effects contribute to forgetting on visuospatial working memory tasks. [ABSTRACT FROM AUTHOR]

Abstract: Based on early findings showing low correlations between intelligence test scores and learning on laboratory tasks, psychologists typically have dismissed the role of learning in intelligence and emphasized the role of working memory instead. In 2006, however, B.A. Williams developed a verbal learning task inspired by three-term reinforcement contingencies and reported unexpectedly high correlations between this task and Raven''s Advanced Progressive Matrices (RAPM) scores [Williams, B.A., Pearlberg, S.L., 2006. Learning of three-term contingencies correlates with Raven scores, but not with measures of cognitive processing. Intelligence 34, 177–191]. The present study replicated this finding: Performance on the three-term learning task explained almost 25% of the variance in RAPM scores. Adding complex verbal working memory span, measured using the operation span task, did not improve prediction. Notably, this was not due to a lack of correlation between complex working memory span and RAPM scores. Rather, it occurred because most of the variance captured by the complex working memory span was already accounted for by the three-term learning task. Taken together with the findings of Williams and Pearlberg, the present results make a strong case for the role of learning in performance on intelligence tests. [Copyright &y& Elsevier]

Cites the effects of domain, retention interval and information load on young and older adults' visuospatial working memory. Age-related differences in visuospatial working memory; Use of information about item locations; Number of sequentially presented items.

Studies the effects of age, domain and processing demands on memory span. Analysis of cross-sectional data from the normative sample of the Wechsler Memory Scale--Third Edition; Regression of memory span on age; Slopes for Spatial and Digit Span; Mechanisms involved in age-related differences in memory span.

In 3 separate experiments, the same samples of young and older adults were tested on verbal and visuospatial processing speed tasks, verbal and visuospatial working memory tasks, and verbal and visuospatial paired-associates learning tasks. In Experiment 1, older adults were generally slower than young adults on all speeded tasks, but age-related slowing was much more pronounced on visuospatial tasks than on verbal tasks. In Experiment 2, older adults showed smaller memory spans than young adults in general, but memory for locations showed a greater age difference than memory for letters. In Experiment 3, older adults had greater difficulty learning novel information than young adults overall, but older adults showed greater deficits learning visuospatial than verbal information. Taken together, the differential deficits observed on both speeded and unspeeded tasks strongly suggest that visuospatial cognition is generally more affected by aging than verbal cognition. [ABSTRACT FROM AUTHOR]

We examined whether the type of response used to report items recalled from short-term memory affects the age difference in verbal and spatial memory spans. Younger and older adults viewed either a series of letters or a series of locations in a grid, and then they reported their memory for the items either vocally or by using a touch screen. Overall, age differences were larger for spatial memory spans than for verbal memory spans, replicating previous results. Changing the response modality affected only older adults' verbal spans, which were approximately one item higher with a vocal response than with a manual response. This resulted in a smaller age difference for verbal items reported vocally than for any other condition. The results can best be explained by age-related difficulties in both spatial processing and in dealing with stimulus-response incongruity. [ABSTRACT FROM AUTHOR]

The present study investigated whether older adults' visuospatial working memory shows effects of environmental support for rehearsal similar to those observed in young adults (Lilienthal, Hale, & Myerson, 2014). When the duration of interitem intervals was 4 s and participants had sufficient time to rehearse, location memory spans were larger in both age groups when environmental support was present than when support was absent. Critically, however, the age-related difference in memory was actually larger when support was provided, suggesting that young and older adults may differ in their rehearsal of to-be-remembered locations. (PsycINFO Database Record [ABSTRACT FROM AUTHOR]

The present study addresses three questions regarding age differences in working memory: (1) whether performance on complex span tasks decreases as a function of age at a faster rate than performance on simple span tasks; (2) whether spatial working memory decreases at a faster rate than verbal working memory; and (3) whether the structure of working memory abilities is different for different age groups. Adults, ages 20-89 (n = 388), performed three simple and three complex verbal span tasks and three simple and three complex spatial memory tasks. Performance on the spatial tasks decreased at faster rates as a function of age than performance on the verbal tasks, but within each domain, performance on complex and simple span tasks decreased at the same rates. Confirmatory factor analyses revealed that domain-differentiated models yielded better fits than models involving domain-general constructs, providing further evidence of the need to distinguish verbal and spatial working memory abilities. Regardless of which domain-differentiated model was examined, and despite the faster rates of decrease in the spatial domain, age group comparisons revealed that the factor structure of working memory abilities was highly similar in younger and older adults and showed no evidence of age-related dedifferentiation. [ABSTRACT FROM AUTHOR]