This paper aims to provide a brief review of 'near infrared spectroscopy' (NIRS) as it is applied in the field of biofeedback. My scope is to encompass the origins and the fundamental principles behind the benefits gained through the inclusion of NIRS training in biofeedback practice and to comment on the works of some key researchers in this field.
The near-infrared spectroscopy (NIRS) is a noninvasive method, neuroimaging, to be estimating brain activity from the blood flow of cerebral cortex. In this article, we present our two studies about the measurement and evaluation of stress. The one study is to investigate the impact of virtual reality (VR) to brain function in order to measure and evaluate brain activities during viewing the moving image constructed of VR. Six healthy undergraduate students viewed two kinds of VR. Similar part of prefrontal cortex activated during viewing both VR. The other research is to investigate the prefrontal region activation to the stress and emotional stimuli. The International Affective Picture System (LAPS, Lang et al., 1995) was used so as to elicit the three kinds of emotional state of the participants (negative, neutral, positive). Data showed that the sort of emotion activated the different area of prefrontal cortex.
This study focuses on heart rate variability to evaluate the autonomic nervous function of patients with anxiety (19 female and 6 male patients with an average age of 47.7 years). We measured the low frequency (LF) and high frequency (HF) components of heart rate variability using finger plethysmography. LF/HF was assumed to represent the activity of sympathetic nerves while HF was assumed to represent the parasympathetic activity. The results showed that the parasympathetic activity was lower among the patients than in the control group (27 females and 6 males with an average age of 48.7 years). The results also indicated a significantly negative correlation between trait anxiety (of STAI) and parasympathetic activity. These results support the use of parasympathetic activity, indexed as the HF component of the heart rate variability, in the objective evaluation of the autonomic nervous function of patients with anxiety.