Participants (N = 34) undertook a CANTAB battery on two separate occasions after fasting and abstaining from fluid intake since the previous evening. On one occasion they were offered 500 ml water shortly before testing, and on the other occasion no water was consumed prior to testing. Reaction times, as measured by Simple Reaction Time (SRT), were faster on the occasion on which they consumed water. Furthermore, subjective thirst was found to moderate the effect of water consumption on speed of responding. Response latencies in the SRT task were greater under the “no water” condition than under the “water” condition, but only for those participants with relatively high subjective thirst after abstaining from fluid intake overnight. For those participants with relatively low subjective thirst, latencies were unaffected by water consumption, and were similarly fast as those recorded for thirsty participants who had consumed water. These results reveal the novel finding that subjective thirst moderates the positive effect of fluid consumption on speed of responding. The results also showed evidence that practice also affected task performance. These results imply that, for speed of responding at least, the positive effects of water supplementation may result from an attenuation of the central processing resources consumed by the subjective sensation of thirst that otherwise impair the execution of speeded cognitive processes.
Keywords: cognition, water, performance, mood, thirst
Citation: Edmonds CJ, Crombie R and Gardner MR (2013) Subjective thirst moderates changes in speed of responding associated with water consumption. Front. Hum. Neurosci. 7:363. doi: 10.3389/fnhum.2013.00363
Received: 14 May 2013; Accepted: 25 June 2013;
Published online: 16 July 2013.
Edited by:Michael Smith, Northumbria University, UK
Reviewed by:Kristen E. D'Anci, Tufts University, USA
Copyright © 2013 Edmonds, Crombie and Gardner. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.
*Correspondence: Caroline J. Edmonds, School of Psychology, University of East London, Stratford Campus, The Green Stratford, London E15 4LZ, UK e-mail: firstname.lastname@example.org