The University of East London School of Psychology in England has found that subjects who drank about three cups of water - 24 ounces per 775 milliliters- before taking a series of cognitive tests - performed better on a test measuring reaction time than subjects who didn''t drink water.
The researchers speculated that being thirsty may take brain’s attention away from the task at hand, thus slowing response time.
“It might be that physiological processes (of drinking or not drinking water) affect performance on different tasks in different ways,” study researcher Caroline Edmonds said.
“Thirst might lead to better performance on some tasks, because the hormone vasopressin, which activates the thirst response, has also been linked to attention and arousal,” she said.
In the new study, 34 adults were asked to abstain from food or drink starting at 9 p.m., and come into a laboratory the next day for testing.
Participants visited the laboratory twice: On one occasion, they were offered a cereal bar for breakfast along with water, and on another day, they were offered a cereal bar and no water.
For the reaction test, participants had to press a button as soon as they saw an object on a computer screen. Reaction times were 14 percent faster among the water group than the no water group.
The study was published in the journal Frontiers in Human Neuroscience on the July 16 issue.