Introduction: Several studies suggest DHEA and DHEAS (DHEA(S)) are related to memory enhancement and a better performance under stress. An anti-cortisol action may contribute to those relations. We looked for a new level of evidence, by studying DHEA(S) and cortisol relations to working memory (WM) and distraction in humans also at the electrophysiological level.
Subjects and methods: Twenty-eight healthy female volunteers (1826 years old) were presented a well-established auditoryvisual distraction task protocol. EEG was recorded during the performance of one task with WM load (WM1) and other without, while ignoring task-irrelevant sounds (80% standard st; 20% novel nov). ERPs were averaged for each auditory-stimulus trial type and WM condition. Novelty-P3 was identified in the nov minus st difference waveforms. Salivary DHEA, DHEAS and cortisol were measured before each task and at 30 and 60 min.
Results: With simultaneous WM load and distraction: i) Hit rate decrease was directly related to basal cortisol (P<0.05) and inversely related to DHEA reactivity (30/0 min) increase between conditions (P<0.05); and ii) Reaction time increase was inversely related to basal cortisol (P<0.05) and directly related to DHEA reactivity increase between conditions (P<0.005).
Regarding auditory ERPs, novelty-P3 amplitude in WM1 was directly related to cortisol/DHEA ratio before that task (P=0.007). In visual ERPs, P300 amplitude in WM1 was directly related to basal DHEAS (P=0.011) and changed due to WM load in direct relation to DHEA reactivity (P=0.005).
Discussion: In more demanding situations, higher basal cortisol was related to faster answers and more errors whereas DHEA reactivity presented opposite relations. At the electrophysiological level, distraction during WM load was in direct relation to cortisol/DHEA ratio and processing of the task-relevant visual stimulus was enhanced by higher basal DHEAS and DHEA reactivity. Overall, higher cortisol level was related to worse performance and more distraction while DHEA(S) showed opposite effects.
27 Apr - 01 May 2013
European Society of Endocrinology