Individual Differences in Hemodynamic Responses Measured on the Head Due to a Long-Term Stimulation Involving Colored Light Exposure and a Cognitive Task: A SPA-fNIRS Study

When brain activity is measured by neuroimaging, the canonical hemodynamic response (increase in oxygenated hemoglobin ([O2Hb]) and decrease deoxygenated ([HHb]) not always seen every subject. The reason for this intersubject-variability of responses still completely understood. This study performed with 32 healthy subjects, using systemic physiology augmented functional near-infrared spectroscopy (SPA-fNIRS) approach. We investigate intersubject variability physiological responses, due to a verbal fluency task (VFT) under colored light exposure (CLE; blue red). Five seven different patterns were detected subgroup analysis red exposure, respectively. also found that arterial oxygen saturation mean pressure positively correlated [O2Hb] at prefrontal cortex during CLE-VFT independent color classification subjects. Our finds there substantial cerebral which partially explained subject-specific changes induced CLE-VFT. means both analyses additional assessment are crucial importance achieve comprehensive understanding effects on human