Water, Hydration Status and Cognitive Performance

Effects of hydration status on cognitive performance and mood

“…These issues with general neuropsychological tests that were not specifically designed for nutritional studies may lead to subtle effects being overlooked and an increase in false-negative reports. To avoid such issues, a number of researchers in this field, including Lieberman ( 43 , 50 ) and Edmonds et al ( 51 , 52 ) , have recommended that standardised cognitive measures, i.e. those that have previously shown sensitivity to nutritional interventions, should be utilised in future studies.…”

“…Despite the expansion of this research area, we still do not have a clear understanding as to how acute water intervention may influence mental performance and its associated neural activity. Researchers have suggested psychological mechanisms related to limited attentional resources during thirst ( 51 , 52 , 80 ) . However, evidence has also highlighted the importance of physiological mechanisms, with findings that the expectancy of water alone does not influence cognitive performance ( 66 ) .…”

“…Psychological mechanisms have been commonly proposed ( 51 , 52 , 80 ) to explain the effect of water consumption on cognitive abilities and mood states. The global workspace model ( 81 ) is a well-known generalised model of cognitive processes that postulates that there are limited amounts of cognitive resources and parallel processes often compete to obtain these resources.…”

“…One question that remains is whether attentional processes in other modalities such as auditory sustained attention would be similarly affected by acute water consumption. These recommendations have been made by researchers in the field ( 39 , 50 , 51 , 66 ) , but have thus far not been implemented in empirical research. Testing these different sensory modalities would help teasing apart whether water intervention improvement is specific to the visual system, as has been found in some flavonoid intervention studies, for example ( 70 ) , or whether higher-level, cross-modal attentional mechanisms are affected.…”

Dose-response effects of water supplementation on cognitive performance and mood in children and adults

“…Children are at particular risk of 418 dehydration for a variety of physiological (e.g. higher total body water content, poor 419 acclimatisation to heat, higher respiratory and metabolic rate) and social (depended on 420 caregivers for access to drinks) reasons (Edmonds, 2012 children's perception of thirst operates differently from that of adults; we report that both 426 adults' and children's thirst ratings were decreased by a drink of 300 ml water, but children's 427 ratings increased after consuming just 25 ml water. However, these data should be replicated 428 before strong conclusions about whether children's ability to perceive and report on the 429 interoceptive signal of thirst is the same as that in adults.…”