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The relationship between dehydroepiandrosterone (DHEA), working memory and distraction--a behavioral and electrophysiological approach.

do Vale S, Selinger L, Martins JM, Gomes AC, Bicho M, do Carmo I, Escera C - PLoS ONE (2014)

Bottom Line: Under working memory load, a higher baseline cortisol/DHEA ratio was related to higher distraction as indexed by an enhanced novelty P3.An increased DHEA production with consecutive cognitive tasks was found and higher DHEA responses attributed to working memory load were related to enhanced working memory processing as indexed by an enhanced visual P300.Overall, the results suggest that in women DHEA may oppose cortisol effects reducing distraction and that a higher DHEA response may enhance working memory at the electrophysiological level.

View Article: PubMed Central - PubMed

Affiliation: Institute for Brain, Cognition and Behavior (IR3C), University of Barcelona, Barcelona, Catalonia, Spain; Cognitive Neuroscience Research Group, Psychiatry and Clinical Psychobiology Department, University of Barcelona, Barcelona, Catalonia, Spain; Endocrinology University Clinic, Lisbon Medical School, University of Lisbon, Lisbon, Portugal; Endocrinology, Diabetes and Metabolism Department, Santa Maria University Hospital, Lisbon, Portugal; Metabolism and Endocrinology Center, Genetics Laboratory, Lisbon Medical School, University of Lisbon, Lisbon, Portugal.

ABSTRACT
Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulphate (DHEAS) have been reported to have memory enhancement effects in humans. A neuro-stimulatory action and an anti-cortisol mechanism of action may contribute to that relation. In order to study DHEA, DHEAS and cortisol relations to working memory and distraction, we recorded the electroencephalogram of 23 young women performing a discrimination (no working memory load) or 1-back (working memory load) task in an audio-visual oddball paradigm. We measured salivary DHEA, DHEAS and cortisol both before each task and at 30 and 60 min. Under working memory load, a higher baseline cortisol/DHEA ratio was related to higher distraction as indexed by an enhanced novelty P3. This suggests that cortisol may lead to increased distraction whereas DHEA may hinder distraction by leading to less processing of the distractor. An increased DHEA production with consecutive cognitive tasks was found and higher DHEA responses attributed to working memory load were related to enhanced working memory processing as indexed by an enhanced visual P300. Overall, the results suggest that in women DHEA may oppose cortisol effects reducing distraction and that a higher DHEA response may enhance working memory at the electrophysiological level.

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Example of trials stimulation sequence (above the line) and correct answers to the tasks (below the line) for the two tasks.A) Discrimination task (WM0), in which subjects had to decide whether the two digits on the screen were equal or different. B) Working memory task (WM1), in which the subjects had to compare the left digit on the screen with the left digit of the previous trial. WM0 – discrimination task; WM1 – working memory task.
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pone-0104869-g001: Example of trials stimulation sequence (above the line) and correct answers to the tasks (below the line) for the two tasks.A) Discrimination task (WM0), in which subjects had to decide whether the two digits on the screen were equal or different. B) Working memory task (WM1), in which the subjects had to compare the left digit on the screen with the left digit of the previous trial. WM0 – discrimination task; WM1 – working memory task.

Mentions: Participants sat in a comfortable chair in a dimly lit and electrically and acoustically shielded room. In the discrimination task (WM0) subjects had to decide whether the two digits appearing on the screen were the same (11 and 22) or different (12 and 21), see figure 1A. In the WM1 task (1-back task) subjects had to decide whether the left or right digit (counterbalanced across subjects) on the screen was the same as the left or right digit of the previous trial (figure 1B). Thus, they had to keep one digit in working memory until the next trial, answering to every trial, except for the first one. Responses were given through a mouse button (one mouse button for “same” and the other button for “different”), also counterbalanced across subjects. The subjects were specifically instructed to respond as quickly and accurately as possible while ignoring the sounds. In order to reduce artifacts originating from eye-blinks and movements during EEG recording, subjects were asked to minimize blinking and to focus on a central fixation cross between the two digits. Before each task, subjects performed practice blocks (composed by 10 trials) without any auditory stimuli until they reached a hit rate of at least 80% in each task.


The relationship between dehydroepiandrosterone (DHEA), working memory and distraction--a behavioral and electrophysiological approach.

do Vale S, Selinger L, Martins JM, Gomes AC, Bicho M, do Carmo I, Escera C - PLoS ONE (2014)

Example of trials stimulation sequence (above the line) and correct answers to the tasks (below the line) for the two tasks.A) Discrimination task (WM0), in which subjects had to decide whether the two digits on the screen were equal or different. B) Working memory task (WM1), in which the subjects had to compare the left digit on the screen with the left digit of the previous trial. WM0 – discrimination task; WM1 – working memory task.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4126777&req=5

pone-0104869-g001: Example of trials stimulation sequence (above the line) and correct answers to the tasks (below the line) for the two tasks.A) Discrimination task (WM0), in which subjects had to decide whether the two digits on the screen were equal or different. B) Working memory task (WM1), in which the subjects had to compare the left digit on the screen with the left digit of the previous trial. WM0 – discrimination task; WM1 – working memory task.
Mentions: Participants sat in a comfortable chair in a dimly lit and electrically and acoustically shielded room. In the discrimination task (WM0) subjects had to decide whether the two digits appearing on the screen were the same (11 and 22) or different (12 and 21), see figure 1A. In the WM1 task (1-back task) subjects had to decide whether the left or right digit (counterbalanced across subjects) on the screen was the same as the left or right digit of the previous trial (figure 1B). Thus, they had to keep one digit in working memory until the next trial, answering to every trial, except for the first one. Responses were given through a mouse button (one mouse button for “same” and the other button for “different”), also counterbalanced across subjects. The subjects were specifically instructed to respond as quickly and accurately as possible while ignoring the sounds. In order to reduce artifacts originating from eye-blinks and movements during EEG recording, subjects were asked to minimize blinking and to focus on a central fixation cross between the two digits. Before each task, subjects performed practice blocks (composed by 10 trials) without any auditory stimuli until they reached a hit rate of at least 80% in each task.

Bottom Line: Under working memory load, a higher baseline cortisol/DHEA ratio was related to higher distraction as indexed by an enhanced novelty P3.An increased DHEA production with consecutive cognitive tasks was found and higher DHEA responses attributed to working memory load were related to enhanced working memory processing as indexed by an enhanced visual P300.Overall, the results suggest that in women DHEA may oppose cortisol effects reducing distraction and that a higher DHEA response may enhance working memory at the electrophysiological level.

View Article: PubMed Central - PubMed

Affiliation: Institute for Brain, Cognition and Behavior (IR3C), University of Barcelona, Barcelona, Catalonia, Spain; Cognitive Neuroscience Research Group, Psychiatry and Clinical Psychobiology Department, University of Barcelona, Barcelona, Catalonia, Spain; Endocrinology University Clinic, Lisbon Medical School, University of Lisbon, Lisbon, Portugal; Endocrinology, Diabetes and Metabolism Department, Santa Maria University Hospital, Lisbon, Portugal; Metabolism and Endocrinology Center, Genetics Laboratory, Lisbon Medical School, University of Lisbon, Lisbon, Portugal.

ABSTRACT
Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulphate (DHEAS) have been reported to have memory enhancement effects in humans. A neuro-stimulatory action and an anti-cortisol mechanism of action may contribute to that relation. In order to study DHEA, DHEAS and cortisol relations to working memory and distraction, we recorded the electroencephalogram of 23 young women performing a discrimination (no working memory load) or 1-back (working memory load) task in an audio-visual oddball paradigm. We measured salivary DHEA, DHEAS and cortisol both before each task and at 30 and 60 min. Under working memory load, a higher baseline cortisol/DHEA ratio was related to higher distraction as indexed by an enhanced novelty P3. This suggests that cortisol may lead to increased distraction whereas DHEA may hinder distraction by leading to less processing of the distractor. An increased DHEA production with consecutive cognitive tasks was found and higher DHEA responses attributed to working memory load were related to enhanced working memory processing as indexed by an enhanced visual P300. Overall, the results suggest that in women DHEA may oppose cortisol effects reducing distraction and that a higher DHEA response may enhance working memory at the electrophysiological level.

Show MeSH