Acute dietary tryptophan depletion impairs maintenance of "affective set" and delayed visual recognition in healthy volunteers.

RATIONALE: Altered serotonergic transmission in affective disorders and Alzheimer's disease has prompted research aimed at defining the precise cognitive effects of depleting central serotonin in humans, using acute dietary tryptophan depletion. OBJECTIVE: We examined the effects of tryptophan...

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Main Authors: Rubinsztein, J, Rogers, R, Riedel, W, Mehta, M, Robbins, T, Sahakian, B
Format: Journal article
Language:English
Published: 2001
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author Rubinsztein, J
Rogers, R
Riedel, W
Mehta, M
Robbins, T
Sahakian, B
author_facet Rubinsztein, J
Rogers, R
Riedel, W
Mehta, M
Robbins, T
Sahakian, B
author_sort Rubinsztein, J
collection OXFORD
description RATIONALE: Altered serotonergic transmission in affective disorders and Alzheimer's disease has prompted research aimed at defining the precise cognitive effects of depleting central serotonin in humans, using acute dietary tryptophan depletion. OBJECTIVE: We examined the effects of tryptophan depletion on mood and cognition in healthy volunteers. Cognitive tests of memory and attentional processing were employed to test hypotheses of central 5-hydroxytryptamine (5-HT) function related to cortical processing. METHODS: A double-blind, parallel design, placebo control study was employed with 15 subjects in each group. Mood rating scales were performed at the start and 5 h after ingestion of the drink. Cognitive tests were also performed at 5 h, after completion of the subjective rating scales. RESULTS: A robust reduction in total tryptophan was achieved in the test group. Subjects receiving the placebo drink showed the expected effect of shift on the affective shifting task, that is, more errors in the more difficult shift versus the non-shift condition. The tryptophan-depleted group made a similar number of errors in the shift trials but failed to reduce the number of errors in the non-shift trials. The tryptophan-depleted group showed a significant impairment on the delayed pattern recognition task. No significant effects on the subjective mood measures were found. CONCLUSIONS: Tryptophan depletion abolished the normal tendency to improve error scores on non-shift trials in response to affective cues on a go/no-go task. We suggest that this inability to "maintain set" in the non-shift condition may be due to a disruption of semantic retrieval processes concerned with affect. The novel finding of impairment on a delayed visual pattern recognition task confirms and extends previous studies where selective effects on memory and learning have been found following acute tryptophan depletion.
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spelling oxford-uuid:5d979926-2b4b-4495-97a5-f39c32d654092022-03-26T17:35:22ZAcute dietary tryptophan depletion impairs maintenance of "affective set" and delayed visual recognition in healthy volunteers.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:5d979926-2b4b-4495-97a5-f39c32d65409EnglishSymplectic Elements at Oxford2001Rubinsztein, JRogers, RRiedel, WMehta, MRobbins, TSahakian, BRATIONALE: Altered serotonergic transmission in affective disorders and Alzheimer's disease has prompted research aimed at defining the precise cognitive effects of depleting central serotonin in humans, using acute dietary tryptophan depletion. OBJECTIVE: We examined the effects of tryptophan depletion on mood and cognition in healthy volunteers. Cognitive tests of memory and attentional processing were employed to test hypotheses of central 5-hydroxytryptamine (5-HT) function related to cortical processing. METHODS: A double-blind, parallel design, placebo control study was employed with 15 subjects in each group. Mood rating scales were performed at the start and 5 h after ingestion of the drink. Cognitive tests were also performed at 5 h, after completion of the subjective rating scales. RESULTS: A robust reduction in total tryptophan was achieved in the test group. Subjects receiving the placebo drink showed the expected effect of shift on the affective shifting task, that is, more errors in the more difficult shift versus the non-shift condition. The tryptophan-depleted group made a similar number of errors in the shift trials but failed to reduce the number of errors in the non-shift trials. The tryptophan-depleted group showed a significant impairment on the delayed pattern recognition task. No significant effects on the subjective mood measures were found. CONCLUSIONS: Tryptophan depletion abolished the normal tendency to improve error scores on non-shift trials in response to affective cues on a go/no-go task. We suggest that this inability to "maintain set" in the non-shift condition may be due to a disruption of semantic retrieval processes concerned with affect. The novel finding of impairment on a delayed visual pattern recognition task confirms and extends previous studies where selective effects on memory and learning have been found following acute tryptophan depletion.
spellingShingle Rubinsztein, J
Rogers, R
Riedel, W
Mehta, M
Robbins, T
Sahakian, B
Acute dietary tryptophan depletion impairs maintenance of "affective set" and delayed visual recognition in healthy volunteers.
title Acute dietary tryptophan depletion impairs maintenance of "affective set" and delayed visual recognition in healthy volunteers.
title_full Acute dietary tryptophan depletion impairs maintenance of "affective set" and delayed visual recognition in healthy volunteers.
title_fullStr Acute dietary tryptophan depletion impairs maintenance of "affective set" and delayed visual recognition in healthy volunteers.
title_full_unstemmed Acute dietary tryptophan depletion impairs maintenance of "affective set" and delayed visual recognition in healthy volunteers.
title_short Acute dietary tryptophan depletion impairs maintenance of "affective set" and delayed visual recognition in healthy volunteers.
title_sort acute dietary tryptophan depletion impairs maintenance of affective set and delayed visual recognition in healthy volunteers
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