Assessment of physiological patterns of acute stress responses: the role of near-infrared spectroscopy

Near-Infrared Spectroscopy (NIRS) is a functional neuroimaging technique based on the properties of light that allows a non-invasive measurement of concentration changes in cortical hemoglobin. Developed in the last 40 years, NIRS can be used to detect non-invasively the activation patterns of cerebral cortex. Its use in the field of psychophysiology has constantly increased over time, thanks to some intrinsic advantages over other neuroimaging techniques.
Even so, one of the areas understudied using NIRS technology is stress responses. The exposure to both acute and chronic psychosocial stressors can lead to unfavorable health outcomes. Moreover, literature collected and meta-analyzed over time shows that the exposition to stressors hyperactivates right frontal areas of the cortex as well as neuroendocrine systems. Interestingly, these findings have been partly replicated by few NIRS studies, even though a number of
methodological and practical issues have been raised. The resolution of these problems could allow in future NIRS studies, to better explore the neurophysiological underpinnings of stress responses and even contribute to study the protective\risk factors of those physical and mental diseases exacerbated by stress.