Rapid detection of near-infrared spectral response of neural activity in prefrontal cortex

Abstract

Due to its non-invasive neuroimaging properties and wide applicability in the field of aviation, fNIRS is chosen as the main tool for studying human factors in aviation. Currently, fNIRS-based brain-computer interface (BCI) and neurofeedback learning systems have a detection time of 4-6 seconds, which does not meet the needs of rapid decision-making by pilots in emergency situations. To shorten the detection time, we look for features to respond faster to subjects' stimuli and improve the feasibility of fNIRS for real-time application in aviation human factors. In this paper, two features of the NIR signal are extracted: the degree of variability feature and the oxygen exchange feature. By calculating the standard deviation, the degree of variability feature is compared between before and after stimulation, and the larger standard deviation indicates the more obvious activation effect of the stimulation on the brain prefrontal. In addition, by assessing the oxygenation between oxygenated hemoglobin and deoxyhemoglobin in each channel, the activation response between different brain regions can be recognized, thus reflecting the occurrence of the stimulus more accurately.that the results shown that the standard deviation of the first-order derivatives of the oxygenated hemoglobin concentration of some of the channels increased compared with the resting state 1.5 s after the stimulus onset, suggesting that the difference between before and after stimulation brain frontal increased. Analysis of the degree of oxygen exchange of channel oxyhemoglobin and deoxyhemoglobin before and after stimulation revealed that in 85% of the trials, the degree of oxygen exchange of certain channels changed significantly between 1 and 2 s after stimulation. Our study suggests that subjects' responses to stimulation and brain prefrontal activity could be detected on the basis of changes in the standard deviation of the first-order derivative of oxyhemoglobin and changes in the degree of oxygen exchange of oxyhemoglobin and deoxyhemoglobin in certain channels within 1 to 2 seconds after stimulation. This finding may enhance the feasibility of NIR imaging in future real-time applications of human factors.

Keywords: Rapid Detection, fNIRS, Variability, Oxygen Exchange

DOI: 10.54941/ahfe1004752