Nicole Caza

Effect of normal aging on the manipulation of information in working memory

The goal of this study is to examine the central executive of working memory in normal aging, specifically focusing on its capacities to manipulate or modify the format of the to-be-recalled material. The central executive was measured with the alphabetical span procedure, during which subjects were asked to recall a random series of words in their alphabetical order. The storage demand was equalized across subjects by adjusting the list lengths according to individual span. Experiments 1, 2, and 3 showed that elderly subjects were not impaired in manipulating information, relative to young controls, even when the difficulty of the task was increased. In Experiment 4, validity was tested by asking young subjects to perform the task under the conditions of full or divided attention. Alphabetical recall was more impaired than direct recall during the divided attention condition, which suggests a larger involvement of the central executive component in the former. These results are discussed in relation to the hypothesis of a central executive impairment being associated with normal aging.

Chapter 26 The effects of surgery and anesthesia on memory and cognition

This chapter describes current findings from the research into postoperative cognitive dysfunction (POCD) following cardiac and non-cardiac surgery in older adults. The evidence suggests that a significant proportion of patients show POCD in the early weeks following surgery and anesthesia. Specific domains of cognition are affected, especially memory. Much less evidence supports the presence of POCD several months or years after surgery, suggesting that POCD may be transient. However, several methodological issues make it difficult to compare findings across studies. Increasing age is among the most consistently reported patient-related risk factor. Other factors more directly related to the surgery and anesthesia are likely to contribute to the pathogenesis of POCD, including inflammatory processes triggered by the surgical procedure. Animal studies have provided valuable findings otherwise not possible in human studies; these include a correlation between the inflammatory response in the hippocampus and the development of POCD in rodents.

How loss of meaning with preservation of phonological word form affects immediate serial recall performance: a linguistic account.

We present HP, a patient who following the occurrence of herpes simplex encephalitis, lost the ability to understand a subset of words while others remained preserved. Of particular interest is the fact that the meaningless items retained their lexical status. HP’s immediate serial recall of meaningless words was thus compared with that of meaningful words to assess the unique contribution of semantic knowledge without the confounding influence of phonological word (lexical) form. The results revealed a clear recall advantage for meaningful over meaningless words, indicating a specific contribution to recall from the semantic level of representation. Furthermore, an error analysis showed that phonemic errors were most common when semantic information was lacking. Interestingly, the same error pattern was found for pseudo-words that shared phonological elements with meaningless words. These findings support a linguistic and interactive activation account of short-term serial recall, which assumes that all levels of representation, including semantic knowledge about words, contribute to recall performance. In addition, the findings provide preliminary evidence that this view may be extended to the recall of pseudo-words, as there appear to be some influences of semantic representation on pseudo-word recall.

A neuropsychological argument for a processing view of memory

Abstract This study examined the case of a brain-damaged patient, I.R., who exhibits the pattern of performance typical of persons with a selective short-term memory deficit. Part 1 reveals a dissociation in performance between impaired short-term memory and preserved long-term memory. Part 2 examines an alternative explanation of I.R.’s performance under a processing view of memory that rejects the notion of dual stores. The results indicate that the patient’s performance on immediate serial recall of short lists was influenced by the semantic properties of items. In contrast, the patient did not use phonological properties. A similar pattern was found in supraspan tasks, in which I.R. demonstrated excellent recall of lexico-semantic material, but impaired memory for phonological information. These data suggest that there is a disruption of memory for phonological features with preserved memory for lexico-semantic features, irrespective of the short-term/long-term memory distinction.

Deficient relational binding processes in adolescents with psychosis: Evidence from impaired memory for source and temporal context

Introduction. Findings from the literature consistently revealed episodic memory deficits in adolescents with psychosis. However, the nature of the dysfunction remains unclear. Based on a cognitive neuropsychological approach, a theoretically driven paradigm was used to generate valid interpretations about the underlying memory processes impaired in these patients. Methods. A total of 16 inpatient adolescents with psychosis and 19 individually matched controls were assessed using an experimental task designed to measure memory for source and temporal context of studied words. Retrospective confidence judgements for source and temporal context responses were also assessed. Results. On word recognition, patients had more difficulty than controls discriminating target words from neutral distractors. In addition, patients identified both source and temporal context features of recognised items less often than controls. Confidence judgements analyses revealed that the difference between the proportions of correct and incorrect responses made with high confidence was lower in patients than in controls. In addition, the proportion of high-confident responses that were errors was higher in patients compared to controls. Conclusions. These findings suggest impaired relational binding processes in adolescents with psychosis, resulting in a difficulty to create unified memory representations. Our findings on retrospective confidence data point to impaired monitoring of retrieved information that may also impair memory performance in these individuals.

Normative Data for the Rey–Osterrieth and the Taylor Complex Figure Tests in Quebec-French People

The Rey-Osterrieth (ROCF) and Taylor (TCF) complex figure tests are widely used to assess visuospatial and constructional abilities as well as visual/non-verbal memory. Normative data adjusted to the cultural and linguistic reality of older Quebec-French individuals is still nonexistent for these tests. In this article, we report the results of two studies that aimed to establish normative data for Quebec-French people (aged at least 50 years) for the copy, immediate recall, and delayed recall trials of the ROCF (Study 1) and the TCF (Study 2). For both studies, the impact of age, education, and sex on test performance was examined. Moreover, the impact of copy time on test performance, the impact of copy score on immediate and delayed recall score, and the impact of immediate recall score on delayed recall performance were examined. Based on regression models, equations to calculate Z scores for copy and recall scores are provided for both tests.

Reduced short-term memory capacity in Alzheimer's disease: the role of phonological, lexical, and semantic processing.

Individuals with Alzheimers disease (AD) are often reported to have reduced verbal short-term memory capacity, typically attributed to their attention/executive deficits. However, these individuals also tend to show progressive impairment of semantic, lexical, and phonological processing which may underlie their low short-term memory capacity. The goals of this study were to assess the contribution of each level of representation (phonological, lexical, and semantic) to immediate serial recall performance in 18 individuals with AD, and to examine how these linguistic effects on short-term memory were modulated by their reduced capacity to manipulate information in short-term memory associated with executive dysfunction. Results showed that individuals with AD had difficulty recalling items that relied on phonological representations, which led to increased lexicality effects relative to the control group. This finding suggests that patients have a greater reliance on lexical/semantic information than controls, possibly to make up for deficits in retention and processing of phonological material. This lexical/semantic effect was not found to be significantly correlated with patients’ capacity to manipulate verbal material in short-term memory, indicating that language processing and executive deficits may independently contribute to reducing verbal short-term memory capacity in AD.

The role of articulatory suppression in immediate false recognition

False memory for critical lures has been widely documented in long-term memory using the Deese/Roediger-McDermott paradigm. Recent evidence suggests that false memory effects can also be found in short-term memory (STM), supporting models that assume a strong relationship between short-term and long-term memory processes. However, no study has examined the role of articulatory suppression on immediate false memory, even though phono-articulatory factors are critically involved in STM performance and are an intrinsic part of all STM accounts. The current study proposes a novel paradigm to assess false memory effects in a STM task under both silent and articulatory suppression conditions. Using immediate serial recognition, in which participants had to judge whether two successive mixed lists of six associated and non-associated words were matched, we examined true recognition of matching lists and false recognition of mismatching lists comprising a critical lure or unrelated distractor in two experiments. Results from both experiments indicated reduced true recognition of matching lists and greater false serial recognition of mismatching lists comprising a critical lure under articulatory suppression relative to silence. These findings provide further support for some current models of verbal short-term memory, which posit a strong relationship between short-term and long-term memory processes.

True and false memories in adolescents with psychosis: Evidence for impaired recollection and familiarity

Introduction. Psychotic patients are impaired on recall and recognition of studied items (true memory) and typically make more false recall (intrusions) and false recognition than controls, reflecting greater susceptibility to false memory. The functional mechanisms underlying these deficits are poorly understood. The aim of this study was to examine recollection and familiarity in true and false memory in psychotic adolescents without long-term exposure to medication and repeated hospitalisations. Methods. Seventeen adolescents with psychosis and 17 matched controls were tested on a DRM false memory paradigm combined with a remember (R)/know (K)/guess (G) procedure. Recall and recognition of targets (studied words), critical lures (associated words) and unrelated distractors were measured. Between-group comparisons were made using t-tests and mixed ANOVAs. Independent estimates for recollection and familiarity were also calculated. Results. True memory was impaired in patients. Similar rates of false memory for critical lures were found in both groups. False memory for unrelated distractors was increased in patients. Contrary to controls, who attributed more R and K responses to targets than lures, patients attributed similar proportions of R and K responses to targets and lures. Furthermore, patients attributed more K responses than controls to all distractors. Conclusions. These findings suggest a deficit in recollection- and familiarity-based memory in psychotic adolescents as well as reliance on preserved gist or meaning-based memory to support poor item-specific memory.

A Validation Study of Memory and Executive Functions Indexes in French-Speaking Healthy Young and Older Adults

Des scores composites mesurant les fonctions temporales médianes (FTM)/la mémoire et les fonctions frontales (FF)/exécutives sont utilisés pour indexer les changements cognitifs reliés au vieillissement. L’utilisation de ces scores en recherche gagne en popularité, mais s’appuie essentiellement sur les résultats de tests neuropsychologiques auprès des populations anglophones. Cette étude visait à valider les scores composites des FTM/la mémoire et FF/exécutives auprès d’adultes francophones. Quatre-vingt-dix-huit participants sains (32 jeunes et 66 âgés) ont été évalués à l’aide de trois tests neuropsychologiques associés aux FTM et cinq tests associés aux FF. Une analyse factorielle effectuée sur les scores résiduels indépendants de l’âge indique que les tests associés aux FTM et ceux associés aux FF se regroupent en deux facteurs distincts. Une analyse de type « bootstrapping » impliquant 1 000 rééchantillons indique que sept tests sont stables. Cette étude valide pour la première fois en français, des scores composites mesurant les FTM et FF. Medial temporal lobe (MTL)/memory and frontal lobe (FL)/executive functions indexes are used to measure changes related to cognitive aging. These indexes are based on composite scores of neuropsychological tests validated in English-speaking populations, and their use in aging research is growing in popularity. This study aimed at validating the MTL/memory and FL/executive functions indexes in French-speaking adults. Ninety-eight healthy participants (32 young and 66 older adults) were tested on eight neuropsychological tests, three associated with MTL/memory functions and five associated with FL/executive functions. Factor analysis indicated that residual scores independent of age and associated with MTL/memory functions grouped under one factor, and residual scores associated with FL/executive functions grouped under another factor. Bootstrapping analysis with 1,000 resamples confirmed stability for seven neuropsychological tests. This study provides the first validation of the MTL/memory and FL/executive functions composite scores in French-speaking adults, which may be used to assess cognitive changes in aging research.