Drinking Water Enhances Cognitive Performance: Positive Effects on Working Memory But Not Long-Term Memory

Previous studies suggest that acute water drinking interventions enhance working memory, particularly digit span. The aims of the present study were twofold. Firstly, to investigate whether the working memory enhancements extend to different components of working memory. Secondly, to evaluate whether drinking water would improve long-term memory task performance. Seventy-four adult participants completed baseline tests and then either drank 300 ml water or nothing. They completed a thirst scale, two working memory tests (digit span and Corsi blocks) and two long-term memory tests (picture recall and word recall). After this, the water group was offered 300 ml water and the control group did not have a drink. Following a 20 min interval, the measures were repeated. The results showed that both working memory tests were improved by drinking water, but long-term memory assessments were not affected. This study adds to the body of evidence that suggests that acute drinking interventions in adults enhance working memory, but not long-term memory, and that it may not be restricted to particular components of working memory.