Optical diagnosis of mental stress: Review

Abstract

Our research group has employed near-infrared spectroscopy (NIRS) as a simple, noninvasive method to investigate neurophysiological mechanisms of response to mental stress and to evaluate the efficacy of relaxation methods for prevention of stress-induced diseases. NIRS revealed that the right prefrontal cortex (PFC) plays a key role in regulation of the hypothalamic-pituitary- adrenal (HPA) system and the autonomic nervous system (ANS) in response to stress. Subjects with right dominant PFC activity during mental stress might be more sensitive to psychological stress associated with hyperactivity of the stress response system.Relaxation induced by administration of fragrance altered the dominant side of the stress-induced PFC activity from the right to the left side, and reduced the hyperactivity of the HPA system. NIRS may be helpful in prevention of stress-induced diseases, since it allows us to assess conveniently and noninvasively the level of mental stress and the effectiveness of various relaxation methods. © 2012 Springer Science+Business Media, LLC.