Students who chewed gum for 5 minutes before taking a test did better on the test than students who did not chew gum before the test, U.S. researchers said. Serge Onyper, an assistant professor at St. Lawrence University in Canton, N.Y., said \"mastication-induced arousal\" is credited for the testing score boost, which lasted for about the first 20 minutes of testing. A \"battery of cognitive tasks\" was given to study participants, who chewed gum either prior to or throughout testing. The results were compared with those of subjects who did not chew gum, Onyper said. Many studies have shown that any type of physical activity can produce a performance boost and this study points out that even mild physical activity can bring on such a boost, Onyper said. \"Chewing gum gave the subjects multiple advantages, but only when chewed for 5 minutes before testing, not for the duration of the test,\" Onyper said in a statement. Benefits persisted for the first 15 to 20 minutes of testing only. Onyper noted it was possible the benefits didn\'t continue throughout testing due to a sharing of resources by cognitive and masticatory processes.