Autobiographical elaboration reduces memory distortion: Cognitive operations and the distinctiveness heuristic.

Retrieval monitoring enhances episodic memory accuracy. For instance, false recognition is reduced when participants base their decisions on more distinctive recollections, a retrieval monitoring process called the distinctiveness heuristic. The experiments reported here tested the hypothesis that autobiographical elaboration during study (i.e., generating autobiographical memories in response to cue words) would lead to more distinctive recollections than other item-specific encoding tasks, enhancing retrieval monitoring accuracy at test. Consistent with this hypothesis, false recognition was less likely when participants had to search their memory for previous autobiographical elaborations, compared to previous semantic judgments. These false recognition effects were dissociated from true recognition effects across four experiments, implicating a recollection-based monitoring process that was independent from familiarity-based processes. Separately obtained subjective measures provided converging evidence for this conclusion. The cognitive operations engaged during autobiographical elaboration can lead to distinctive recollections, making them less prone to memory distortion than other types of deep or semantic encoding. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Failing to Get the Gist: Reduced False Recognition of Semantic Associates in Semantic Dementia.

In 2 experiments involving patients with semantic dementia, the authors investigated the impact of semantic memory loss on both true and false recognition. Experiment 1 involved recognition memory for categories of everyday objects that shared a predominantly semantic relationship. The patients showed preserved item-specific recollection for the pictorial stimuli but, compared with control participants, exhibited significantly reduced utilization of gist information regarding the categories of objects. The latter result is consistent with the patients' degraded semantic knowledge. Experiment 2 involved categories of abstract objects that were related to one another perceptually rather than semantically. Patients with semantic dementia obtained item-specific recollection and gist memory scores that were indistinguishable from those of control participants. These results suggest that the reduction in gist memory in semantic dementia is largely specific to semantic representations and cannot be attributed to general difficulty with abstracting and/or utilizing gistlike commonalities between stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

False recognition of pictures versus words in Alzheimer's disease: The distinctiveness heuristic.

False recognition of semantic associates can be reduced when older adults also study pictures representing each associate. D. L. Schacter, L. Israel, and C. Racine (1999) attributed this reduction to the operation of a distinctiveness heuristic: a response mode in which participants demand access to detailed recollections to support a positive recognition decision. The authors examined patients with probable Alzheimer's disease (AD) and older adults with this paradigm. Half of the participants studied pictures and auditory words; the other half studied visual and auditory words. Older adults who studied pictures were able to reduce their false alarms compared with those who studied words only. AD patients who studied pictures were unable to reduce their false alarms compared with those who studied words only and, in fact, exhibited trends toward greater false recognition. Implications for understanding semantic memory in AD patients are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual false recognition in Alzheimer's disease.

Previous research has found that patients with probable Alzheimer's disease (AD) show lower levels of false recognition of semantic associates than do healthy older adults. To investigate whether this finding is attributable to semantic impairments in patients with AD, the authors examined false recognition of perceptually related novel objects with little semantic content in patients with AD and healthy older adults. By using corrected recognition scores to control for unrelated false alarms, it was found that patients with AD showed lower levels of both true and false recognition of novel objects than did older adults. These results suggest that the previous difference in false recognition of semantic associates observed between patients with AD and older adults is not entirely attributable to semantic memory deficits in patients with AD but may also involve poorly developed gist information in these patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Elevated False Recognition in Patients With Frontal Lobe Damage Is Neither a General Nor a Unitary Phenomenon.

This study examined verbal recognition memory in amnesic patients with frontal lesions (AF), nonamnesic patients with frontal lesions (NAF), and amnesic patients with medial temporal lesions (MT). To examine susceptibility to false alarms, the number of studied words drawn from various categories was varied. The AF and MT groups demonstrated reduced hits and increased false alarms. False alarms were especially elevated when item-specific recollection was strongest in control participants. The NAF group performed indistinguishably from control participants, but several patients showed excessive false alarms in the context of normal hit rates. These patients exhibited impaired monitoring and verification processes. The findings demonstrate that elevated false recognition is not characteristic of all frontal patients and may result from more than 1 underlying mechanism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When false recognition is unopposed by true recognition: Gist-based memory distortion in Alzheimer's disease.

The authors examined false recognition of semantic associates in patients with probable Alzheimer's disease (AD), older adults, and young adults using a paradigm that provided rates of false recognition after single and multiple exposures to word lists. Using corrected false recognition scores to control for unrelated false alarms, the authors found that (a) the level of false recognition after a single list exposure was lower in AD patients than in controls; (b) across 5 trials, false recognition increased in AD patients, decreased in young adults, and showed a fluctuating pattern in older adults; and (c) all groups showed an increase in true recognition over the 5 trials. Analyses suggested that AD patients built up semantic gist across trials, whereas both control groups were able to use increased item-specific recollection and more conservative response criteria to suppress gist-based false alarms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory for gist and detail information in Alzheimer's disease and mild cognitive impairment.

Two experiments examined different forms of gist and detail memory in people with Alzheimer's disease (AD) and those with amnestic mild cognitive impairment (MCI). In Experiment 1, 14 AD, 14 MCI, and 22 control participants were assessed with the Deese-Roediger-McDermott paradigm. Results indicated that false recognition of nonstudied critical lures (gist memory) was diminished in the AD compared with the MCI and control groups; the two latter cohorts performed similarly. In Experiment 2, 14 AD, 20 MCI, and 26 control participants were tested on a text memory task. Results revealed that recall of both macropropositions (gist information) and micropropositions (detail information) decreased significantly in AD and in MCI as compared with control participants. This experiment also revealed that the impairment was comparable between gist and detail memory. In summary, the results were consistent across experiments in the AD but not in the MCI participants. The discrepancy in MCI participants might be explained by differences in the degree of sensitivity of the experimental procedures and/or by the differences in the cognitive processes these procedures assessed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative Recognition in Alzheimer's Disease: Evidence for Impaired Recall-to-Reject.

Patients with mild Alzheimer's disease (AD) were compared with age-matched control subjects on an associative recognition task. Subjects studied pairs of unrelated words and were later asked to distinguish between these same studied pairs (intact) and new pairs that contained either rearranged studied words (rearranged) or nonstudied words (nonstudied). Studied pairs were presented either once or 3 times. Repetition increased hits to intact pairs in both groups, but repetition increased false alarms to rearranged pairs only in patients. This latter pattern indicates that repetition increased familiarity of the rearranged pairs, but only the control subjects were able to counter this familiarity by recalling the originally studied pairs (a recall-to-reject process). AD impaired this recall-to-reject process, leading to more familiaritybased false alarms. These data support the idea that recollection-based monitoring processes are impaired in mild (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Retrieval monitoring and anosognosia in Alzheimer's disease.

This study explored the relationship between episodic memory and anosognosia (a lack of deficit awareness) among patients with mild Alzheimer's disease (AD). Participants studied words and pictures for subsequent memory tests. Healthy older adults made fewer false recognition errors when trying to remember pictures compared with words, suggesting that the perceptual distinctiveness of picture memories enhanced retrieval monitoring (the distinctiveness heuristic). In contrast, although participants with AD could discriminate between studied and nonstudied items, they had difficulty recollecting the specific presentation formats (words or pictures), and they had limited use of the distinctiveness heuristic. Critically, the demands of the memory test modulated the relationship between memory accuracy and anosognosia. Greater anosognosia was associated with impaired memory accuracy when participants with AD tried to remember words but not when they tried to remember pictures. These data further delineate the retrieval monitoring difficulties among individuals with AD and suggest that anosognosia measures are most likely to correlate with memory tests that require the effortful retrieval of nondistinctive information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using what we know: Consequences of intentionally retrieving gist versus item-specific information.

The effect of a prior gist-based versus item-specific retrieval orientation on recognition of objects and words was examined. Prior item-specific retrieval increased item-specific recognition of episodically related but not previously tested objects relative to both conceptual- and perceptual-gist retrieval. An item-specific retrieval advantage also was found when the stimuli were words (synonyms) rather than objects but not when participants overtly named objects during gist-based recognition testing, which suggests that they did not always label objects under general gist-retrieval instructions. Unlike verbal overshadowing, labeling objects during recognition attenuated (but did not eliminate) test- and interference-related forgetting. A full understanding of how retrieval affects subsequent memory, even for events or facts that are not themselves retrieved, must take into account the specificity with which that retrieval occurs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

False recognition and the right frontal lobe: a case study

We described a patient, BG, who exhibited a striking pattern of false recognition after an infarction of the right frontal lobe. Seven experiments document the existence of the phenomenon, explore its characteristics, and demonstrate how it can be eliminated. BG showed pathologically high false alarm rates when stimuli were visual words (experiments 1 and 4), auditory words (experiment 2), environmental sounds (experiment 3), pseudowords (experiment 5), and pictures (experiment 7). His false alarms were not merely attributable to the semantic or physical similarity of studied and non-studied items (experiments 4 and 5). However, BG's false recognitions were virtually eliminated by presenting him with categorized stimuli and testing him with new stimuli from non-studied categories (experiments 6 and 7). The results suggest that BG's false alarms may be attributable to an over-reliance on memory for general characteristics of the study episode, along with impaired memory for specific items. The damaged right frontal lobe mechanisms may normally support the monitoring and/or retrieval processes that are necessary for item-specific recognition.     

Metacognition and False Recognition in Alzheimer's Disease: Further Exploration of the Distinctiveness Heuristic.

The distinctiveness heuristic is a response mode in which participants expect to remember vivid details of an experience and make recognition decisions on the basis of this metacognitive expectation. The authors examined whether the distinctiveness heuristic could be engaged to reduce false recognition in a repetition-lag paradigm in patients with Alzheimer's disease (AD). Patients with AD were able to use the distinctiveness heuristic--though not selectively--and thus they showed reduction of both true and false recognition. The authors suggest that patients with AD can engage in decision strategies on the basis of the metacognitive expectation associated with use of the distinctiveness heuristic, but the patients' episodic memory impairment limits both the scope and effectiveness of such strategies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

False memories in children and adults: Age, distinctiveness, and subjective experience.

This study investigated developmental trends associated with the Deese/Roediger-McDermott false-memory effect, the role of distinctive information in false-memory formation, and participants' subjective experience of true and false memories. Children (5- and 7-year-olds) and adults studied lists of semantically associated words. Half of the participants studied words alone, and half studied words accompanied by pictures. There were significant age differences in recall (5-year-olds evinced more false memories than did adults) but not in recognition of critical lures. Distinctive information reduced false memory for all age groups. Younger children provided with distinctive information, and older children and adults regardless of whether they viewed distinctive information, expressed higher levels of confidence in true than in false memories. Source attributions did not significantly differ between true and false memories. Implications for theories of false memory and memory development are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impaired Implicit Memory for Gist Information in Amnesia.

In 2 experiments using a converging associates paradigm, the authors evaluated implicit memory for gist information in amnesic patients. In Experiment 1, participants saw multiple sets of associates, each converging on a nonpresented theme word, and were then tested using an implicit word stem completion test and an explicit cued recall test. Amnesic patients showed intact implicit and impaired explicit memory for studied words, but memory for nonpresented lures was impaired, regardless of retrieval instructions. To evaluate whether impaired implicit memory for lures was due to accelerated forgetting of gist information, short study lists were used in Experiment 2, each consisting of a single set of associates. Amnesics' implicit memory for lures was again impaired. These results point to an inability to encode robust gist representations as the cause of impaired gist memory in amnesia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

False memories seconds later: The rapid and compelling onset of illusory recognition.

Distortions of long-term memory (LTM) in the converging associates task are thought to arise from semantic associative processes and monitoring failures due to degraded verbatim and/or contextual memory. Sensory-based coding is traditionally considered more prevalent than meaning-based coding in short-term memory (STM), whereas the converse is true of LTM, leading to the expectation that false memory phenomena should be less robust in a canonical STM task. These expectations were violated in 2 experiments in which participants were shown lists of 4 semantically related words and were probed immediately following a filled 3- to 4-s retention interval or approximately 20 min later in a surprise recognition test. Corrected false recognition rates, confidence ratings, and Remember/Know judgments reveal similar false memory effects across STM and LTM conditions. These results indicate that compelling false memory illusions can be rapidly instantiated and that, consistent with unitary models of memory, they originate from processes that are not specific to LTM tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Item and associative memory in amnestic mild cognitive impairment: Performance on standardized memory tests.

The earliest neuroanatomical changes in amnestic mild cognitive impairment (aMCI) involve the hippocampus and entorhinal cortex, structures implicated in the integration and learning of associative information. The authors hypothesized that individuals with aMCI would have impairments in associative memory above and beyond the known impairments in item memory. A group of 29 individuals with aMCI and 30 matched control participants were administered standardized tests of object-location recall and symbol-symbol recall, from which both item and associative recall scores were derived. As expected, item recall was impaired in the aMCI group relative to controls. Associative recall in the aMCI group was even more impaired than was item recall. The best group discriminators were measures of associative recall, with which the sensitivity and specificity for detecting aMCI were 76% and 90% for symbol-symbol recall and were 86% and 97% for object-location recall. Associative recall may be particularly sensitive to early cognitive change in aMCI, because this ability relies heavily on the medial temporal lobe structures that are affected earliest in aMCI. Incorporating measures of associative recall into clinical evaluations of individuals with memory change may be useful for detecting aMCI. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gist memory in Alzheimer's disease: Evidence from categorized pictures.

The authors investigated gist memory (the general meaning, idea, or gist conveyed by a collection of items) for categorized color photographs in patients with Alzheimer's disease (AD) using an experimental paradigm in which participants are instructed to respond "yes" when a test item fits with a previously studied category, regardless of whether the specific item was actually studied. Compared with controls, the patients endorsed fewer studied items and similar numbers of nonstudied lure items. After the authors corrected for the baseline false-alarm rate, the patients showed a lower level of endorsements for nonstudied lure items compared with that of controls, suggesting that their gist memory is impaired. Implications of these findings for understanding gist memory and response bias in patients with AD are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What is the connection between true and false memories? The differential roles of interitem associations in recall and recognition.

Veridical memory for presented list words and false memory for nonpresented but related items were tested using the Deese/Roediger and McDermott paradigm. The strength and density of preexisting connections among the list words, and from the list words to the critical items, were manipulated. The likelihood of producing false memories in free recall varied with the strength of connections from the list words to the critical items but was inversely related to the density of the interconnections among the list words. In contrast, veridical recall of list words was positively related to the density of the interconnections. A final recognition test showed that both false and veridical memories were more likely when the list words were more densely interconnected. The results are discussed in terms of an associative model of memory, Processing Implicit and Explicit Representations (PIER 2) that describes the influence of implicitly activated preexisting information on memory performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental reversals in false memory: Now you see them, now you don't!

A developmental reversal in false memory is the counterintuitive phenomenon of higher levels of false memory in older children, adolescents, and adults than in younger children. The ability of verbatim memory to suppress this age trend in false memory was evaluated using the Deese-Roediger-McDermott (DRM) paradigm. Seven and 11-year-old children studied DRM lists either in a standard condition (whole words) that normally produces high levels of false memory or in an alternative condition that should enhance verbatim memory (word fragments). Half the children took 1 recognition test, and the other half took 3 recognition tests. In the single-test condition, the typical age difference in false memory was found for the word condition (higher false memory for 11-year-olds than for 7-year-olds), but in the word fragment condition false memory was lower in the older children. In the word condition, false memory increased over successive recognition tests. Our findings are consistent with 2 principles of fuzzy-trace theory's explanation of false memories: (a) reliance on verbatim rather than gist memory causes such errors to decline with age, and (b) repeated testing increases reliance on gist memory in older children and adults who spontaneously connect meaning across events. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Impairment of memory for spatial context in schizophrenia.

A group of 33 patients with schizophrenia were compared with control participants using a spatial memory task in which words were presented on locations of a grid. In the first part of the experiment, recognition of target information (words) was tested. In the second, 2 tasks of spatial location (contextual information) were given involving different sets of words placed in different locations: A location memory task (determining which word was in a particular spatial location) explored an associative form of spatial memory, and a relocation task (determining where a particular word was located) explored an associative and a nonassociative form of spatial memory. Patients were more impaired with regard to the location memory task than to the target recognition and relocation tasks. The impairment was negatively correlated with Stroop task performance. The results suggest that schizophrenia is associated with a spatial context memory deficit, which could be due to defective associations between target and spatial information. This deficit seemed to be related to frontal dysfunction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)