Functional Mechanisms Underlying Impaired Recognition Memory and Conscious Awareness in Patients With Schizophrenia

Danion, Jean-Marie; Rizzo, Lydia; Bruant, Agnès

doi:10.1001/archpsyc.56.7.639

Cited by 286 publications

(181 citation statements)

References 33 publications

Supporting

Mentioning

150

Contrasting

Unclassified

Order By: Relevance

“…Interestingly, levels of cued recall were lower than stem completion throughout, but lowest in the high-dose ketamine group where twice as many stems were completed with targets in the implicit compared to the explicit task. This would accord with the suggestion that in situations where conscious awareness is impaired, it may serve to have inhibitory effects on explicit memory (Danion et al 1999). Preserved perceptual priming is of interest as no previous study has examined the effects of ketamine on this form of memory.…”

Section: Discussionsupporting

confidence: 71%

Acute Effects of Ketamine on Memory Systems and Psychotic Symptoms in Healthy Volunteers

Morgan

Mofeez

Brandner

et al. 2003

Neuropsychopharmacol

239

174

View full text Add to dashboard Cite

N-methyl-D-aspartate (NMDA) receptor antagonists have been demonstrated to induce schizophrenia-like symptoms and cognitive impairment in humans. The NMDA receptor has been strongly implicated in memory, but research to date on the effects of NMDA antagonists has examined only some aspects of human memory functions. This study used a double-blind, placebo-controlled, independent groups design with 54 healthy volunteers to examine the effects of infusions of two doses (0.4, 0.8 mg/kg) of the NMDA antagonist ketamine upon the five human memory systems, aspects of executive functioning and schizophrenia-like and dissociative symptoms. Ketamine produced a dose-dependent impairment to episodic and working memory and a slowing of semantic processing. Ketamine also impaired recognition memory and procedural learning. Attention, perceptual priming and executive functioning were not affected following the drug. In addition, ketamine induced schizophrenia-like and dissociative symptoms, which were not correlated with the cognitive measures. These data suggest that, in humans, ketamine produces a selective pattern of impairments to working, episodic, and procedural memory but not to perceptual priming, attention or aspects of executive functioning.

show abstract

Section: Discussionsupporting

confidence: 71%

Acute Effects of Ketamine on Memory Systems and Psychotic Symptoms in Healthy Volunteers

Morgan

Mofeez

Brandner

et al. 2003

Neuropsychopharmacol

239

174

View full text Add to dashboard Cite

show abstract

“…Evidence for a problem of this type in memory tasks has recently been reported in a series of studies by Danion and his colleagues (e.g. Danion et al 1999 ;Bacon et al 2001). These authors conclude that the memory problems shown by patients with schizophrenia lie in the domain of meta-memory and reflect an impaired conscious awareness of one's own knowledge.…”

Section: A Disorder Of Consciousness ?mentioning

confidence: 92%

Schizophrenia and theory of mind

2004

View full text Add to dashboard Cite

We suspect that people have an everyday theory of mind because they explain and frequently talk about the behaviour of others and themselves in terms of beliefs and desires. Having a theory of mind means that we believe that other people have minds like ours and that we understand the behaviour of these others in terms of the contents of their minds: their knowledge, beliefs and desires. But how can we demonstrate experimentally that people are using their theory of mind to predict the behaviour of others. This problem is particularly acute in the case of animals or young human children when they do not have language. Dennett (1978) discussing Premack & Woodruff's (1978) seminal paper ‘Does the chimpanzee have a theory of mind?’, suggested that the use of false beliefs to explain behaviour would provide convincing evidence. When their belief is true (i.e. corresponds to the actual state of the world) we can explain peoples' behaviour on the basis of the state of the world without needing to know about their beliefs. This ambiguity does not arise when the belief is false. The first experiment to use this approach was published by Wimmer & Perner (1983). They showed that at around 4 years of age a child knows that Maxi will look for his chocolates where Maxi believes them to be, even though the child knows that this belief is false because he has seen Maxi's mother moving the chocolates. In the English-speaking world the task involving Maxi and the chocolates has become the Sally-Anne task (see this issue, Lee et al. 2004).

show abstract

“…determining if information was self-generated or provided by the experimenter) (Bentall et al, 1991;Rankin and O'Carroll, 1995). Such findings raise the possibility that episodic memory deficits in patients with schizophrenia may be related to a failure of binding features together to create more complex representations (Rizzo et al, 1996;Danion et al, 1999). Most studies, however, do not separately assess memory for individual features and memory for bound features.…”

Section: Introductionmentioning

confidence: 99%

Impaired performance in a working memory binding task in patients with schizophrenia

Burglen

Marczewski

Mitchell

et al. 2004

Psychiatry Research

Self Cite

View full text Add to dashboard Cite

This study investigated feature binding in a working memory task in patients with schizophrenia and in normal controls. Twenty-five patients and 25 controls participated. On each trial, three drawings of familiar objects were presented sequentially, each in a different cell of a 3=3 grid. In different blocks of trials, participants remembered either individual features (object and location conditions) or an object and its location (combination condition). The results showed that patients were slower and less accurate than controls under all conditions. Accuracy of both groups was reduced in the combination condition relative to the single-feature conditions, but patients showed disproportionately poorer performance in the combination condition than in the object and location conditions. Thus, patients with schizophrenia exhibit deficits in working memory, particularly when the task requires binding objects to their locations. This finding demonstrates that processes that establish coherent and temporary episodic representations in working memory are impaired in schizophrenia. ᮊ

show abstract

Functional Mechanisms Underlying Impaired Recognition Memory and Conscious Awareness in Patients With Schizophrenia

Abstract: Patients with schizophrenia are unable to link the separate aspects of events into a cohesive, memorable, and distinctive whole. The corollary of this defective relational binding is a quantitative and qualitative impairment of autonoetic awareness.

Cited by 286 publications

References 33 publications

Acute Effects of Ketamine on Memory Systems and Psychotic Symptoms in Healthy Volunteers

Acute Effects of Ketamine on Memory Systems and Psychotic Symptoms in Healthy Volunteers

Schizophrenia and theory of mind

Impaired performance in a working memory binding task in patients with schizophrenia

Contact Info

Product

Resources

About