False Memories: Young and Older Adults Think of Semantic Associates at the Same Rate, but Young Adults Are More Successful at Source Monitoring.

Two experiments explored whether the higher vulnerability to false memories in the DRM (J. Deese, 1959; H. L. Roediger & K. B. McDermott, 1995) paradigm in older compared to young adults reflects a deficit in source monitoring. In both experiments, adding together the number of falsely recalled critical lures and the number of critical lures produced on a post-recall test asking participants to report items that they had thought of but did not recall, indicated that the critical lures were activated during the experiment equally often in young and older adults. However, older adults were more likely than young adults to say that they had actually heard the lures. When strongly encouraged to examine the origin of memories (Experiment 2), the warning substantially reduced false recall in young but not older adults. These results are consistent with the idea that older adults have more difficulty later identifying the source of information that was activated as a consequence of intact semantic activation processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of bilingualism, aging, and semantic relatedness on memory under divided attention.

We examined how encoding and retrieval processes were affected by manipulations of attention, and whether the degree of semantic relatedness between words in the memory and distracting task modulated these effects. We also considered age and bilingual status as mediating factors. Monolingual and bilingual younger and older adults studied a list of words from a single semantic category presented auditorily, and later free recalled them aloud. During either study or retrieval, participants concurrently performed a distracting task requiring size decisions to words from either the same or a different semantic category as the words in the memory task. The greatest disruptions of memory from divided attention (DA) were for encoding rather than retrieval. The effect of semantic relatedness was significant only for DA at encoding. Older age and bilingualism were associated with lower recall scores in all conditions, but these factors did not influence the magnitude of memory interference. The results suggest that encoding is more sensitive to semantic similarity in a distracting task than is retrieval. The role of attention at encoding and retrieval is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attention and retrieval from long-term memory.

Conducted 9 experiments with 152 female volunteers (mean age 44.4 yrs) to investigate the disrupting effect of a secondary task on retrieval from long-term memory. Exps I–V studied the influence of concurrent card sorting or digit span on free recall or paired-associate learning of word lists. Exp VI explored recall probability using a recognition paradigm in which accuracy and latency could be measured simultaneously. Exp VII explored the latency effect with a semantic memory paradigm, and Exp VIII required Ss to make semantic category judgments while retaining sequences of 6 digits. Exp IX examined the effect of concurrent digital load on the rate of generating items from semantic categories. Overall findings reveal that a demanding concurrent task did not reduce the probability of retrieving an item from semantic or episodic memory. However, concurrent load during learning substantially effected recall performance. A concurrent task during retrieval did not have a clear effect on latency. The contrast between the pattern shown by errors and by that shown by latencies suggests that attempts to estimate the attentional demands of any task should be interpreted with considerable caution when based on a single measure, such as performance errors, performance latency, or a response to a probe RT signal. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How many memory systems? Evidence from aging.

The present research tested Tulving's (1985) ternary memory theory. Young (ages 19–32) and older (ages 63–80) adults were given procedural, semantic, and episodic memory tasks. Repetition, lag, and codability were manipulated in a picture-naming task, followed by incidental memory tests. Relative to young adults, older adults exhibited lower levels of recall and recognition, but these episodic measures increased similarly as a function of lag and repetition in both age groups. No age-related deficits emerged in either semantic memory (vocabulary, latency slopes, naming errors and tip-of-the-tongue responses) or procedural memory (repetition priming magnitude and rate of decline). In addition to the age by memory task dissociations, the manipulation of codability produced slower naming latencies and more naming errors (semantic memory), yet promoted better recall and recognition (episodic memory). Finally, a factor analysis of 11 memory measures revealed three distinct factors, providing additional support for a tripartite memory model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic activation and episodic memory: Age similarities and differences.

In 2 experiments, 48 19–35 yr olds and 48 59–75 yr olds were engaged in semantic and nonsemantic orienting tasks and were subsequently given incidental or expected recall and recognition tasks. Reaction time (RT) patterns from the orienting tasks suggested that all Ss experienced similar semantic activation during encoding. Under incidental conditions, age differences in memory performance were minimal. When memory tests were expected, younger Ss recalled and recognized more items than did older Ss, suggesting that younger Ss were more effective in their deployment of mnemonic strategies. The age difference was particularly pronounced for unattended items, which suggests an age difference in the capacity to encode all of the episodic information. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory failures in progressive idiopathic dementia.

14 patients with progressive idiopathic dementia (PID) were compared with 14 normal controls (average age 61.2 yrs) on psychometric and laboratory measures of cognitive processes. Patients had significantly lower scores than controls on the Wechsler Memory Scale and the WAIS Performance IQ, but not on WAIS Verbal or Full Scale IQ or Digit Span tests. Patients performed more poorly on learning and memory tasks than controls. Unlike the latter, patients' recall of categorized word lists was no better than their recall of unrelated words, and they did not consistently remember information that had been previously recalled. Patients also were unable to generate as many words that start with a given letter or that belong to a given category as controls did. Data show that while many intellectual functions are preserved, PID patients are unable to access structures in semantic memory and therefore fail to effectively encode episodic events so that they are memorable. Differences in cognitive dysfunction in PID and in depression are discussed. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparing Source-Based and Gist-Based False Recognition in Aging and Alzheimer's Disease.

This study examined 2 factors contributing to false recognition of semantic associates: errors based on confusion of source and errors based on general similarity information or gist. The authors investigated these errors in patients with Alzheimer's disease (AD), age-matched control participants, and younger adults, focusing on each group's ability to use recollection of source information to suppress false recognition. The authors used a paradigm consisting of both deep and shallow incidental encoding tasks, followed by study of a series of categorized lists in which several typical exemplars were omitted. Results showed that healthy older adults were able to use recollection from the deep processing task to some extent but less than that used by younger adults. In contrast, false recognition in AD patients actually increased following the deep processing task, suggesting that they were unable to use recollection to oppose familiarity arising from incidental presentation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Big" versus "little" science: comparative analysis of program projects and individual research grants

The verbal fluency task requires generation of category exemplars and appears to be an example of what M. Moscovitch (1995) calls a strategic test of memory retrieval. Four experiments explored the role of individual differences in working memory (WM) capacity on verbal fluency under various secondary load conditions. High WM participants consistently recalled more exemplars. However, load conditions caused a decline in recall only for high WM participants. Low WM participants showed no effect of secondary workload on exemplar generation. WM group differences and load effects were observed even in the 1st min of retrieval, which suggests that differences were not due to differences in knowledge. A model of retrieval is supported that relies on cue-based-automatic activation, monitoring of output for errors, controlled suppression of previously recalled items, and controlled strategic search.     

Feeling of knowing in episodic memory following moderate to severe closed-head injury.

The ability to accurately monitor one's memory is a metacognitive process that is important in everyday life. The authors examined episodic memory feeling-of-knowing (FOK) ratings in 21 moderate to severe closed-head injury (CHI) participants (more than 1 year postinjury) and 21 controls. Participants studied 36 critical cue-target word pairs. Following a brief delay, they were asked to recall the target that corresponded to a given cue. Confidence ratings were made for recalled words, and FOK judgments were made for nonrecalled words in terms of the likelihood of recognizing the target word on a subsequent recognition test. CHI participants demonstrated less accurate recall but accurate ability to judge their recall performance (retrospective memory monitoring). They also demonstrated intact FOK judgments when providing binary judgments but demonstrated difficulties making finer discriminations on an ordinal scale (prospective memory monitoring). These findings suggest that memory monitoring is not a unitary construct. It is proposed that CHI participants may display intact memory monitoring when predictions are based on familiarity assessment but not when continued probing for additional episodic information is required. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in incidental learning.

Examined the effects of age and of incidental-learning tasks on recall of a categorized word list. Ss were 50 18-30 yr old college students and 50 55-65 yr old teachers. The control groups were instructed to remember the words; incidental-learning groups performed orienting tasks, but were not informed that they would have to recall the words. 2 orienting tasks required that Ss process the meaning of the words; the other 2 orienting tasks did not involve semantic processing. Analysis of the free-recall data indicates that the semantic processing tasks led to much greater recall and organization of recall than the nonsemantic orienting tasks. In recall, there was a significant interaction between age and orienting task, with old Ss only manifesting incidental learning that was inferior to young Ss, whose orienting task involved semantic processing. The findings indicate that the presence or absence of an age-related decrement in incidental learning is predictable from the depth of processing of the incidentally acquired material. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative relatedness enhances recall and produces false memories in immediate serial recall.

The influence of permanent lexical network in immediate serial recall is well established. The corresponding influence of permanent semantic networks is less clear, although such networks are known to both facilitate memory in long-term memory tasks and to produce false memories in those same tasks. The current experiment involves the study of Deese-Roediger-McDermott (DRM) lists for immediate serial recall. The trials in the experiment involved presenting the six strongest items from the DRM lists either in intact associatively related lists or where those items had been randomly mixed to produce unrelated lists. The results of the experiment indicated that the associatively related lists were better recalled in order than unrelated lists and the nonpresented critical lure was falsely recalled relatively frequently. The results of the experiment confirm the importance of associative semantic networks in short-term memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of working memory capacity in retrieval.

The verbal fluency task that requires generation of category exemplars and appears to be an example of what M. Moscovitch (1995) calls a strategic test of memory retrieval. Four experiments explored the role of individual differences in working memory (WM) capacity on verbal fluency under various secondary load conditions. High WM participants consistently recalled more exemplars. However, load conditions caused a decline in recall only for high WM participants. Low WM participants showed no effect of secondary workload on exemplar generation. WM group differences and load effects were observed even in the 1st min of retrieval, which suggests that differences were not due to differences in knowledge. A model of retrieval is supported that relies on cue-based-automatic activation, monitoring of output for errors, controlled suppression of previously recalled items, and controlled strategic search. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Confidence level and feeling of knowing for episodic and semantic memory: an investigation of lorazepam effects on metamemory

The effects of lorazepam (0.026 or 0.038 mg/kg), a benzodiazepine, and of a placebo on metamemory, i.e. knowledge about one's own memory capabilities, were investigated in 36 healthy volunteers. Accuracy of confidence levels (CL) in the correctness of recalled answers and accuracy of feeling of knowing (FOK) the answers when recall fails were measured using a sentence memory task assessing episodic memory and a task consisting of general information questions and assessing semantic memory. Lorazepam impaired episodic memory. Unexpectedly, it also impaired performance in both the recall and recognition phases of the task assessing semantic memory, suggesting that it decreased the ability to distinguish between correct and incorrect information. In episodic memory, lorazepam 0.038 mg/kg-treated subjects exhibited an impaired CL accuracy, compared to placebo-treated subjects, and their FOK accuracy was at chance. In semantic memory, their overall CL and FOK accuracy was apparently spared. However, these subjects selectively overestimated their CL judgements for incorrect answers; moreover, secondary analyses showed that FOK accuracy for a subset of low-accuracy items was virtually nil. These results suggest that lorazepam impairs metamemory for both episodic and semantic memory.     

Neural correlates of cued recall with and without retrieval of source memory

A source memory procedure was used to investigate whether event-related potentials (ERPs) reflect the retrieval of episodic information (recollection) on tests of word-stem cued recall. 'Cued recall ERP effects' for recalled items were found to differ only in their magnitudes, and not their scalp distributions, according to the accuracy of source memory. This finding strongly supports the hypothesis that cued recall ERP effects reflect quantitative variation in the amount or quality of information which can be retrieved about recently experienced events. Topographic analyses also revealed that the distribution of the cued recall ERP effects changed over time, reflecting the activity of at least two temporally and neuroanatomically dissociable neural populations contributing to recollection on this task.     

Effects of aging on source monitoring: Differences in susceptibility to false fame.

Older adults were less likely than young adults to spontaneously recollect the source of familiarity for previously read nonfamous names. Older adults were more likely to call old nonfamous names famous when subsequently encountered in a fame judgment task. Poor source monitoring by the elderly could not be accounted for by inability to recognize earlier read nonfamous names when specifically asked to do so. Both source-monitoring errors and recognition memory performance were based on attributions made about the experience of familiarity. Elderly subjects most prone to making familiarity errors recalled fewer items on a verbal learning task and were less likely to chunk information into semantic categories as it was recalled. This finding suggests that a decline in the tendency to spontaneously organize and integrate information underlies the poor source monitoring observed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Concreteness and semantic repetition effects in free recall: Evidence for dual-coding theory.

Tested the prediction of A. Paivio's (1971, 1976) dual-coding model, which states that semantic-repetition effects will be obtained for concrete but not abstract words. Dual-coding theory also asserts that semantic equivalents are encoded as a combination of separate verbal representations for all words and common imaginal representations for concrete equivalents. 96 undergraduates recalled a list that contained no-repetition, synonym-repetition, and identical-repetition items, half of which were concrete and half of which were abstract. Results show that, for concrete words, recall of synonym- and identical-repetition items did not differ significantly, and both conditions facilitated recall relative to no-repetition items. For abstract words, however, recall of synonym- and no-repetition items did not differ significantly, whereas identical-repetition items facilitated recall relative to both of these conditions. Findings support the prediction and demonstrate the importance of concreteness in semantic-repetition effects. (French abstract) (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Maximizing the benefits and minimizing the costs of repeated memory tests for older adults.

Repeatedly trying to remember information can help people remember more but can also lead to inaccuracies. Two experiments examined whether the costs of repeated recall efforts can be minimized for older adults by using memory tests that require specification of the source of recalled items. Participants saw and imagined pictures and then took 3 successive recall tests in which they either indicated the source of each remembered item (source recall) or simply recalled the items without specification of their source (free recall). Results showed that recall increased systematically from Test 1 to Test 3, although the rate of increase was less marked for older adults, and older adults recalled less overall. After the free recall tests, older adults made more source misattributions (claiming to have seen imagined items) than did young adults, but after the source recall tests, age differences were not significant. Thus, repeatedly recalling items while considering their source was associated with benefits in terms of increased recall and fewer costs in terms of source errors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic and episodic relations are experimentally dissociable and stochastically independent.

In 2 experiments with 407 undergraduates, Ss who studied DOG-BEER and WINE-SWEATER were more likely to recall BEER cued by DOG if they used interactive imagery rather than separate imagery, but the groups showed no difference in recall of BEER cued by WINE. Recall of BEER cued by WINE was enhanced if BEER and alcoholic beverages had been presented before the list was studied, but recall of BEER cued by DOG was unaffected. It is concluded that there are 2 independent types of relation. An episodic relation records the joint occurrence of previously unrelated words; a semantic relation reflects events in one's prior life. The value of a semantic relation is enhanced if the target item is primed in its family; the value of an episodic cue is enhanced by processes that directly encode the occurrence of the 2 items as a unique event in the S's life. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)