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Biomedical subjects

D Grangé

Publications and source records attributed to D Grangé.

6 recordsLinked to original sources

Effects of chlorpromazine and lorazepam on explicit memory, repetition priming and cognitive skill learning in healthy volunteers.

To assess the influence of neuroleptics on explicit memory and two forms of implicit memory, repetition priming and cognitive skill learning, the effects of two low doses of chlorpromazine (12.5 and 25 mg orally) were contrasted to those of lorazepam (2.5 mg orally) and of a placebo using a free-recall task, a word-completion task and repeated testing on the Tower of Toronto puzzle, a version of the Tower of Hanoi puzzle. Seventy-two healthy volunteers took part in this double-blind study. Chlorpromazine spared free-recall and word-completion performance, but impaired the acquisition of a cognitive routine in the subjects who completed the first trials of the Tower of Toronto puzzle efficiently. Lorazepam induced an opposite pattern of memory disruption. These preliminary results suggest that chlorpromazine and lorazepam induced a double dissociation between priming and the acquisition of a cognitive routine. They provide evidence that the two forms of implicit memory rely upon distinct neurochemical systems, the latter, but not the former, being dependent upon dopaminergic systems.

Adult

Differential effects of diazepam and lorazepam on repetition priming in healthy volunteers.

The effects of two benzodiazepines, diazepam (15 or 20 mg orally) and lorazepam (1.75 or 2.5 mg orally), and a placebo on explicit memory, lexical priming and perceptual priming were assessed using a free-recall, a word-completion and a picture-completion test. The picture-completion test included two different study conditions intended to manipulate the magnitude of the priming effect. Sixty healthy volunteers took part in this double-blind study. Free-recall performances were altered by both drugs. Lorazepam impaired word-completion and picture-completion performance, whereas diazepam only exhibited a deleterious effect on the more sensitive of the two measures of the picture-completion test. These results indicate that the two benzodiazepines have differential amnestic effects. It is suggested that these differential effects could be accounted for by a different cortical distribution of the two benzodiazepines.

Adult

Explicit memory and repetition priming in depression. Preliminary findings.

Explicit memory and repetition priming, a form of implicit memory, were examined in depressed patients and controls. Explicit memory of depressed patients was severely impaired, whereas repetition priming was intact. These results are consistent with the hypothesis that the impairment of memory in depression is linked to a failure of effort-demanding cognitive processes. Repetition priming might be useful in differentiating between depression and dementia.

Dementia

Effects of scopolamine, trimipramine and diazepam on explicit memory and repetition priming in healthy volunteers.

The effects of scopolamine, an anticholinergic drug, of trimipramine, a tricyclic antidepressant with both anticholinergic and sedative properties, of diazepam and a placebo, on explicit memory and repetition priming were assessed using a free-recall task and a word-stem completion task. Forty-eight healthy volunteers took part in this double-blind study. Diazepam provoked a dissociation between free recall, which was profoundly impaired, and word completion, which was spared. No significant changes in memory performances were observed in the scopolamine group; however, a significant correlation between explicit and implicit memory performances was observed in this group. At the low dose used, the effects of trimipramine on memory were mild. The results suggest that the cholinergic system is involved in the priming effect.

Adult

Diazepam induces a dissociation between explicit and implicit memory.

The effects of 0.2 mg/kg orally administered diazepam and of a placebo on explicit memory, implicit and knowledge memory were assessed using a free recall task, a word-stem completion task and two category-generation tasks. Twenty four healthy volunteers took part in this double-blind study. Diazepam impaired explicit but not implicit memory. The drug also spared knowledge memory. Explicit memory was linked with the diazepam-induced sedation and with the self-rated affective load of to-be remembered words, but implicit memory was not. The diazepam-induced dissociation between explicit and implicit memory supports the notion of two distinct forms of memory and reproduced the dissociation observed in organic amnesia.

Adult