At the beginning of a 30-minute computer-based vigilance task, the average reaction time of participants who were chewing gum was about 70 milliseconds slower than that of non-chewers, but by the end, it was about 100 milliseconds faster, suggesting that chewing gum can stem a decline of vigilance over a long task, says a team led by Kate Morgan of Cardiff University in the UK. Gum chewing has been shown to increase blood flow to the frontal-temporal region of the brain.
