Chewing on gum alters the expression of contagious yawning

The motor action pattern of yawning enhances neurovascular circulation, which appears to function in cooling the brain and promoting adaptive behavioral outcomes linked with arousal and state change. Here, the authors tested whether chewing on gum, which induces similar mandibular contractions and temporarily increases alertness, alters the expression of yawning. Participants were assigned to either a control, mint, or gum condition and instructed to watch a contagious yawning stimulus in the laboratory. Yawning behavior was scored from video recordings. Findings showed that both sucking on a mint and chewing a piece of gum significantly inhibited contagion in these trials, as both manipulations diminished the overall rate and frequency of yawning in the sample. However, unlike sucking on a mint, chewing gum distinctly reduced and restricted the magnitude of the peak muscular contraction (i.e., the duration) of yawns and this measure correlated negatively with the frequency of chewing during testing. Overall, these findings add to our understanding of the physiology of yawning and provide directions for future research examining connections between yawning and cognitive performance. Keywords: blood flow, brain temperature, cognitive performance, cortical arousal, mandibular contractions, swallowing. __________________________________________________________
 Gallup, A.C. & Engert, K. (2019). Chewing on gum alters the expression of contagious yawning. Human Ethology, 34, 93-103. https://doi.org/10.22330/he/ 34/093-103 submitted: 12.Mar. 2019; revised: 20.May 2019; accepted: 22.May 2019 Gallup, A.C. & Engert, K. (2019). Gum chewing and contagious yawning Human Ethology, 34, 93-103