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Memory for context and its use in item memory: comparisons of younger and older persons.

This study compared memory for words and the font in which they appeared (or the voice speaking them) in young and old participants, to explore whether age-related differences in episodic word memory are due to age-related differences in memory for perceptual-contextual information. In each of 3 experiments, young and older participants were presented with words to learn. The words were presented in either 1 of 2 font types, or in 1 of 2 male voices, and participants paid attention either to the fonts or voices or to the meaning of the words. Participants were then tested on both word and font or voice memory. Results showed that younger participants had better explicit memory for font and voice memory and for the words themselves but that older participants benefited at least as much as younger people when perceptual characteristics of the words were reinstated. There was no evidence of an age-related impairment in the encoding of perceptual-contextual information.

Adult↗

The association of memory complaint with computer-simulated everyday memory performance.

The relationship of memory self-report to self-rated depression and to actual performance on computer-simulated everyday memory tasks was investigated in 125 normal adults. Canonical correlation analyses demonstrated that self-rated memory performance and objective computer-simulated everyday memory performance shared from 27.9% to 29.4% of common variance. These data provide initial concurrent validity for a new memory self-report scale, the MAC-S. Results are discussed in relation to psychometric factors important in the design and validation of self-report memory scales.

Adolescent↗

Working memory for sign language: a window into the architecture of the working memory system.

Traditionally, working memory has been divided into two major domains: verbal and visuo-spatial. The verbal domain of working memory can be characterized either by its relationship to language or by its grounding in auditory processing. Because of this ambiguity, languages that are not auditory and vocal (i.e., signed languages) pose a challenge to this conception of working memory. We describe several experiments with deaf users of American Sign Language (ASL) that explore the extent to which the architecture of working memory is determined by the constraints of auditory and visual processing and the extent to which it is determined by the characteristics of language. Various working memory effects were investigated: phonological similarity, word length, and articulatory suppression. The pattern of evidence strongly supports the existence of a sign-based 'rehearsal loop' mechanism parallel to the speech-based rehearsal loop. However, we also discuss evidence pointing to differences between the speech loop and the sign loop from forward and backward digit span tasks with deaf and hearing subjects. Despite their similarities based on linguistic properties, the speech loop and the sign loop appear to diverge due to the differing processing demands of audition and vision. Overall, the results suggest that the architecture of working memory is shaped both by the properties of language structure and by the constraints imposed by sensorimotor modality.

Journal Article↗

Mismaking memories: neural precursors of memory illusions in electrical brain activity.

Memory illusions--vivid experiences of events that never occurred--could result from inaccuracies either in retrieving memories or in initially storing them. In two experiments, people studied lists of associated words that either did or did not induce later illusory (false) memories of associated but nonpresented lure words. The amplitude of the electrical brain activity during study of words (approximately 500-1,300 ms) that were themselves later correctly remembered reliably distinguished list words that led to such illusory memories from those that did not. This encoding difference associated with subsequent illusory memory (referred to as a DIM)--presumably reflecting item-specific encoding differences--is a neural precursor of memory illusions.

Brain↗

Recovered memory and the Daubert criteria: recovered memory as professionally tested, peer reviewed, and accepted in the relevant scientific community.

Research during the past two decades has firmly established the reliability of the phenomenon of recovered memory. This review first highlights the strongest evidence for the phenomenon itself and discusses the survey, experimental, and biological evidence for the varying mechanisms that may underlie the phenomenon. Routes to traumatic amnesia from dissociative detachment (loss of emotional content leading to loss of factual content) and from dissociative compartmentalization (failure in integration) are discussed. Next, an argument is made that false memory is a largely orthogonal concept to recovered memory; the possibility of one phenomena is largely irrelevant to the potential for the other. Furthermore, some aspects of the false memory research offer supportive data for the recovered memory researcher. Finally, the issue of error rates in making the Daubert case is explored. It is concluded that the weight of the evidence should allow the recovered memory victim to come before the court.

Amnesia↗

The early memories procedure: a projective test of autobiographical memory, Part 1.

This article introduces the Early Memories Procedure (EMP), the first projective test of autobiographical memory. The EMP requires minimal one-on-one professional time, because it is a self-administered pencil-and-paper test. Part 1 of the EMP includes five spontaneous early childhood memories (EMs) and one particularly clear or important memory (lifetime); Part 2 contains 15 directed memories, including both EMs and more recent memories. The procedure is intended to be used after intake by new clients, because it provides the clinician with an opportunity to explore client problem areas with a minimum of face-to-face time. The experiential aspect of the procedure helps to reduce the initial anxiety and confusion experienced by novice therapy clients by providing a lesson regarding what some of the more important aspects of therapy are about: understanding the self and its needs, taking responsibility, and making changes consistent with one's needs and goals. Due to its length, the article is divided in half, and each half is published separately. Part 1 introduces the EMP and provides a rationale for its use. Part 2 illustrates how EMs can be interpreted with the cognitive-perceptual model and presents a full EMP protocol and interpretation.

Affective Symptoms↗

Memory for to-be-performed tasks versus memory for performed tasks.

Memory for subject-performed tasks-that is, for simple actions such as lifting a pen, which subjects perform overtly-is better than memory for verbal tasks-that is, when subjects only listen to the action phrases. Here I investigated whether this effect depends on actual performance or whether it also shows up when there is only an intention to perform the task. Koriat, Ben-Zur, and Nussbaum (1990) found that the intention to perform items at test enhanced free recall more than did verbal tasks. Brooks and Gardiner (1994), however, were not able to replicate this finding. In four experiments, I attempted to reconcile this discrepancy by comparing subject-performed tasks, to-be-performed tasks, and verbal tasks under different conditions. The outcome depended on whether a within-subjects design or a between-subjects design was used. In the between-subjects design, memory for subject-performed tasks was better than memory for to-be-performed tasks, and both of these led to better recall performance than did verbal tasks. In a within-subjects design, in contrast, memory for to-be-performed tasks was no different from memory for verbal tasks. These results were independent of whether the test mode was congruent or incongruent. Thus, the discrepant findings of Koriat et al and of Brooks and Gardiner seem to be due to the design used, pointing to encoding processes as the critical variable. The present results are interpreted to show that actual performance of actions at study provides more information than does only the intention to perform actions at test.

Adult↗

Memory for musical tempo: additional evidence that auditory memory is absolute.

We report evidence that long-term memory retains absolute (accurate) features of perceptual events. Specifically, we show that memory for music seems to preserve the absolute tempo of the musical performance. In Experiment 1, 46 subjects sang two different popular songs from memory, and their tempos were compared with recorded versions of the songs. Seventy-two percent of the productions on two consecutive trials came within 8% of the actual tempo, demonstrating accuracy near the perceptual threshold (JND) for tempo. In Experiment 2, a control experiment, we found that folk songs lacking a tempo standard generally have a large variability in tempo; this counters arguments that memory for the tempo of remembered songs is driven by articulatory constraints. The relevance of the present findings to theories of perceptual memory and memory for music is discussed.

Adolescent↗

[Memory advantage of performed actions: comments on multimodal memory theory].

Based on the integration of the memory advantage for subject-performed actions into the multimodal theory of episodic memory by J. Engelkamp (1997), three issues referring to the so-called enactment effect are discussed and addressed by statistical r-analyses. Firstly, the empirical basis of the functional distinction between motor and non-motor memory resources by means of dual-task experiments is questioned. Secondly, a multinomial modeling analysis is presented which aims at the contributions of automatic and controlled memory processes to the enactment effect in the process-dissociation paradigm. Finally, the effect of enactment on memory for serial order information is discussed with respect to recent accounts of serial memory.

Attention↗

[False memories: an interface between normal memory and pathology].

One of the most unexpected aspects of our memory is the existence of false memories. This phenomenon concerns the recall or recognition of events that never took place. Since a few years, the study of false memories became a field of research particularly active in psychology and neuropsychology. The objective of this review is to examine the various studies undertaken on false memories, while being interested more specifically by the influence of age and Alzheimer's disease on their production. We discuss then the mechanisms of production of false memories reviewing the assumptions related to the organization of semantic memory and to executive functions.

Aged↗

6-OHDA lesions of the nucleus accumbens accentuate memory deficits in animals with lesions to the forebrain cholinergic projection system: effects of nicotine administration on learning and memory in the water maze.

The separate and combined effects of lesions to the forebrain cholinergic projections system (FCPS) and to dopamine (DA) terminals in the nucleus accumbens (n.acc) were assessed in two water maze tasks: (1) standard acquisition using two trials/day with a 10 min intertrial interval (ITI) for 15 days with the platform in the same position and (2) a working memory task requiring matching to a platform position located by chance on Trial 1, with four trials/day separated by a 30-s ITI and a different platform position on each of 4 days. Effects of nicotine (0.1 mg/kg) were also examined in animals with FCPS, n.acc, and combined lesions in order to determine whether facilatory effects of nicotine in FCPS lesioned animals are mediated by dopamine release in the n.acc. The FCPS and combined lesion groups were impaired in both tasks, but the combined lesion group was substantially worse than animals with FCPS lesions alone. The n.acc lesion group did not differ from controls. Nicotine did not affect acquisition in either the FCPS or combined lesion group, but impaired learning in animals with n.acc lesions. In the working memory task nicotine exerted a nonspecific facilatory effect in the FCPS and combined lesion groups, by reducing latency to find the platform both on the first trial and on the subsequent matching to position trials. Choline acetyltransferase (ChAT) activity was reduced in hippocampus and cortex in the FCPS lesion group, whereas DA levels in n.acc were increased. Conversely, in the n.acc lesion group accumbal DA levels were reduced, while cortical and hippocampal ChAT activity was increased, suggesting that reciprocal changes were induced by the separate lesions. However the combined lesion group showed mixed and more widespread effects; ChAT activity was unaltered in cortex and substantially reduced in hippocampus, and DA levels were reduced in both n.acc and caudate. The results indicate that combined FCPS and n.acc lesions impair spatial learning and working memory far more severely than FCPS lesions alone, although this does not reflect simple additive reductions in DA and ChAT activity. Nicotine improved spatial search strategy, and effect detected in the in the working memory task with daily changes in platform position, rather than in the standard acquistion task, but did not appear specifically to improve working memory. Since the facilitatory effect of nicotine was seen in both FCPS and combined lesion groups, the findings suggest that nicotine-induced improvements do not depend on accumbal DA release.

Animals↗

Short-term and long-term memory deficit following intracarotid Amytal injection: further support for the memory consolidation hypothesis.

To test the three main hypotheses of the human amnesic syndrome (encoding, consolidation, retrieval), we designed an original protocol for memory assessment under Amytal that included, in addition to a retrograde memory measure, both short-term and long-term anterograde memory measures. Twenty epileptic patients with SEEG-confirmed unilateral temporal lobe foci were given right and left injections on successive days. Only the long-term memory measure for material presented under Amytal was significantly related to the presence of a temporal contralateral epileptogenic focus, even if it was assessed when the hemisphere had completely recovered from the effect of Amytal. Short-term memory deficits were observed equally often after injections ipsilateral and contralateral to the epileptogenic focus, and no retrograde amnesia was observed. These results are consistent with the consolidation hypothesis.

Adolescent↗

Temporal lobe epilepsy as a model to understand human memory: the distinction between explicit and implicit memory.

Decades of research have provided substantial evidence of memory impairments in patients with temporal lobe epilepsy (TLE), including deficits in the encoding, storage, and retrieval of new information. These findings are not surprising, given the associated underlying neuroanatomy, including the hippocampus and surrounding medial temporal lobe structures. Because of its associated anatomic and cognitive characteristics, TLE has provided an excellent model by which to examine specific aspects of human memory functioning, including classic distinctions such as that between explicit and implicit memory. Various clinical and experimental research studies have supported the idea that both conscious and unconscious processes support memory functioning, but the role of relevant brain structures has been the subject of debate. This review is concerned with a discussion of the current status of this research and, importantly, how TLE can inform future studies of memory distinctions.

Epilepsy, Temporal Lobe↗

Memory disorders in Alzheimer's disease and the organization of human memory.

The Squire and Zola-Morgan parallel organization model of the memory and the Tulving hierarchical model were developed mainly through the study of amnesic patients. The predictions of these two models are different, the first being more open to double dissociations and less restrictive than the second. Alzheimer's Disease is characterized by a differential impairment of the memory systems and by an interindividual variability which may take the form of dissociations between preserved and disturbed abilities in some patients. The objective of this study was to use the memory dysfunctions of patients with AD to test the validity of the two models. Analysis of the group data provided an average profile of memory disturbance consistent both with much of the data given in AD literature and with the two models. Using a multiple single-case strategy, we demonstrated several simple dissociations which are for the greater part compatible with the two models. Two of the dissociations underline the limits of the Tulving model, which otherwise accounts for a lot of results. The study supports the relevance of AD for the understanding of the cognitive architecture of the human memory.

Aged↗

Delayed recognition memory in Parkinson's disease: a role for working memory?

Immediate and delayed recognition memory for words was examined in a sample of 16 non-demented patients with Parkinson's disease and 16 normal control participants of equivalent age and educational attainment. The patients, relative to control participants, had intact immediate but impaired delayed recognition memory performance. Patients were also impaired on tests of free and cued recall, working memory and a measure of psychomotor processing speed. Processing speed was a significant covariate for delayed recognition, free and cued recall and working memory performance, but not for immediate recognition performance. These results suggest that the same cognitive processes which support performance on tests of recall and working memory also support performance on tests of delayed recognition.

Aged↗

Mecamylamine blocks enhancement of reference memory but not working memory produced by post-training injection of nicotine in rats tested on the radial arm maze.

The focus of this study was to analyze whether the psychostimulant nicotine would enhance reference and working memory consolidation in rats tested on the 8-arm radial arm maze. Mecamylamine, a nicotine antagonist, was used to attempt to block the enhancement of memory consolidation. All rats were given one training trial/day for 12 consecutive days, and 4 arms were baited. Rats were separated into five groups: the saline-nicotine group received an intraperitoneal (i.p.) injection of saline immediately after each trial followed 15 min later by an subcutaneous (s.c.) injection of nicotine (0.6 mg/kg free base); the nicotine-delay group received an s.c. injection of nicotine 2 h after each training trial, two groups received an i. p. injection of one of two different doses of mecamylamine (2.5 and 6.0 mg/kg) immediately after each trial, which was followed 15 min later by an s.c. nicotine injection, and a control group received an i.p. injection of saline immediately and 15 min after each training trial. Results showed that the saline-nicotine group made fewer reference and working memory errors than the saline- or nicotine-delay groups, but only the effect of nicotine on reference memory was blocked by the higher dose of mecamylamine. It appears from these results that nicotine's effects on reference and working memory may be mediated through different mechanisms.

Animals↗

A brain model with the circuit to convert short-term memory into long-term memory.

Assuming the existence of encoding synapses which record presynaptic axonal 'on-off' patterns as the contents of memory, and the existence of modulating synapses which help encoding synapses develop long-term potentiation and depression so as to convert short-term memory into long-term memory, it is possible to outline a brain model according to neuroanatomy. The loop of memory-conversion consists of the axons connecting the perceptive cortices, mesotemporal lobes, dorsomedial nuclei of thalamus (which also receive axons from septohippocampal complex and, indirectly, fornices), and prefrontal lobes. The contents of thought, feeling, dreaming, hallucination, and delusion all result from activation of different axonal 'on-off' patterns in many sets of synapses, and retrieval of memory, reactivation of the presynaptic axonal 'on-off' patterns in the correlating sets of synapses. In this model, degenerated synapses may be responsible for the thought disorder of schizophrenia.

Animals↗

Memory, abuse, and science. Questioning claims about the false memory syndrome epidemic.

Careful assessment of purported scientific discoveries and the resulting interpretations is a responsibility of every scientist. The area of memory, particularly memory for abuse, has recently seen new, highly publicized claims. These include the proposal of a new diagnostic category, the false memory syndrome; claims about the ease with which extensive autobiographical memories can be implanted; and estimates of the extent therapists use risky practices likely to cause false memory syndrome. This article suggests questions to evaluate these claims and the methods used to promote them. Implications for clinical standards and malpractice are discussed.

Humans↗