Biomedical subjects

Jaap M J Murre

Publications and source records attributed to Jaap M J Murre.

6 recordsLinked to original sources

PubMed2006

A retrospective controlled study into memory complaints reported by depressed patients after treatment with electroconvulsive therapy and pharmacotherapy or pharmacotherapy only.

Few studies have been conducted comparing complaints of memory problems using objective and subjective memory scales in depressed patients who received electroconvulsive therapy (ECT) + pharmacotherapy or treatment with pharmacotherapy only. Patients who suffer from depression according to the Diagnostic and Statistical Manual of Mental Disorder (Fourth Edition) criteria and who were admitted within the past 5 years before this study in a general psychiatric hospital were screened for inclusion. Objective retrograde amnesia was assessed using the Autobiographical Memory Interview and the Amsterdam Media Questionnaire (AMQ). Subjective retrograde amnesia was assessed using the Squire Subjective Memory Questionnaire and the ECT Retrograde Amnesia and Perception Scale (ERAPS), a newly developed scale. Twenty of the 84 patients who received ECT + pharmacotherapy and 30 of the 196 patients who received pharmacotherapy only participated in the study. Patients' ERAPS memory scores were compared with proxies' ERAPS memory scores of the patients to assess the reliability of memory complaints. The ECT + pharmacotherapy group was found to suffer more from memory problems using the AMQ 1990 test. There was also a difference for the proxy's ERAPS memory score, reflecting the conviction of proxies from the ECT + pharmacotherapy patients that these patients suffer more memory problems due to the illness, treatment with pharmacotherapy, or ECT. The differences could not be explained by the influence of determinants for retrograde amnesia. ECT + pharmacotherapy patients did not attribute their memory problems mainly to ECT but put equal "blame" on the depressive illness, treatment with pharmacotherapy, and ECT. The analyses suggest that the AMQ 1990s test is (more) sensitive in registering retrograde amnesia than the other scales used in the study.

Amnesia, Retrograde↗

PubMed2006

Memory for time: how people date events.

The effect of different formats on the accuracy of dating news and the distribution of personal events was examined in four conditions. In the first, participants had to date events in the absolute time format (e.g., "July 2004"), and in the second, they had to date events in the relative time format (e.g., "3 weeks ago"). In the other conditions, they were asked to choose between the two formats. We found a small backward telescoping effect for recent news events and a large forward telescoping effect for remote events. Events dated in the absolute time format were more accurate than those dated in the relative time format. Furthermore, participants preferred to date news events with the relative time format and personal events with the absolute time format, as well as preferring to date remote events in the relative time format and recent events in the absolute time format.

Adult↗

PubMed2005

Reduced parahippocampal connectivity produces schizophrenia-like memory deficits in simulated neural circuits with reduced parahippocampal connectivity.

CONTEXT: Episodic memory impairments are well characterized in schizophrenia, but their neural origin is unclear. OBJECTIVE: To determine whether the episodic memory impairments in schizophrenia may originate from reduced parahippocampal connectivity. DESIGN: Experimental in silico model. SETTING: Department of Psychology, University of Amsterdam, Amsterdam, the Netherlands. INTERVENTIONS: A new, in silico medial temporal lobe model that simulates normal performance on a variety of episodic memory tasks was devised. The effects of reducing parahippocampal connectivity in the model (from perirhinal and parahippocampal cortex to entorhinal cortex and from entorhinal cortex to hippocampus) were evaluated and compared with findings in schizophrenic patients. Alternative in silico neuropathologies, increased noise and loss of hippocampal neurons, were also evaluated. RESULTS: In the model, parahippocampal processing subserves integration of different cortical inputs to the hippocampus and feature extraction during recall. Reduced connectivity in this area resulted in a pattern of deficits that closely mimicked the impairments in schizophrenia, including a mild recognition impairment and a more severe impairment in free recall. Furthermore, the schizophrenic model was not differentially sensitive to interference, also consistent with behavioral data. Notably, neither increased noise levels nor a reduction of hippocampal nodes in the model reproduced this characteristic memory profile. CONCLUSIONS: Taken together, these findings highlight the importance of parahippocampal neuropathology in schizophrenia, demonstrating that reduced connectivity in this region may underlie episodic memory problems associated with the disorder.

Entorhinal Cortex↗

PubMed2005

The reminiscence bump in autobiographical memory: effects of age, gender, education, and culture.

We investigated the age distribution of autobiographical memories with the Galton-Crovitz method through the Internet. Almost 2000 participants in the United States and the Netherlands aged between 11 and 70 years participated. They were presented with 10 cue words, and were asked to recall and date autobiographical memories. We found strong evidence for a "reminiscence bump" in all participant groups at all ages, with peaks at ages 15--18 for men and 13--14 for women. This peak could be localised more precisely than in previous studies due to our large sample size. We were able to remove the forgetting effect from the empirical age distribution with a method that allows separate estimation of memory encoding and forgetting. American participants showed a tendency to report older memories than the Dutch. Age group and level of education did not influence the lifetime encoding function.

Adolescent↗

PubMed2004

Consolidation of long-term memory: evidence and alternatives.

Memory loss in retrograde amnesia has long been held to be larger for recent periods than for remote periods, a pattern usually referred to as the Ribot gradient. One explanation for this gradient is consolidation of long-term memories. Several computational models of such a process have shown how consolidation can explain characteristics of amnesia, but they have not elucidated how consolidation must be envisaged. Here findings are reviewed that shed light on how consolidation may be implemented in the brain. Moreover, consolidation is contrasted with alternative theories of the Ribot gradient. Consolidation theory, multiple trace theory, and semantization can all handle some findings well but not others. Conclusive evidence for or against consolidation thus remains to be found.

Amnesia, Retrograde↗

PubMed2004

Simulating episodic memory deficits in semantic dementia with the TraceLink model.

Although semantic dementia is primarily characterised by deficits in semantic memory, episodic memory is also impaired. Patients show poor recall of old autobiographical and semantic memories, with better retrieval of recent experiences; they can form new memories, and normal performance on pictorial recognition memory has been demonstrated. As these abnormalities in episodic memory are virtually a mirror image of those seen in the amnesic syndromes, semantic dementia poses a challenge to extant models of remote memory and amnesia. Here, we show that one such model, TraceLink, can reproduce some of the principal findings on episodic memory in semantic dementia. A loss of nodes and connections within the trace system, which can be identified with the temporal neocortical memory storage sites implicated in semantic dementia, simulates without further assumptions the findings reported above.

Amnesia↗