Pathways to yawning: making sense of the Thompson cortisol hypothesis

Yawning apparatus and the exact location of the yawn reflex remains controversial. Yet yawning is a significant behavioural response that may potentially be a new diagnostic marker of neurological disease such as multiple sclerosis. Evidence of brain cooling following yawning supports the Thompson Cortisol Hypothesis which postulates the association between cortisol, electrical nerve activity and yawning within the known stress-response system, the Hypothalamus-Pituitary-Adrenal-axis. Changes in cortisol levels are important because they present as a new potential diagnostic tool in the early diagnosis of neurological symptoms.