Abstract
Methods of contemporary physics are increasingly important for biomedical research. For a multitude of diverse reasons there exists a gap between practitioners of biomedicine and modern physics methodologies. In this work, the technique of surrogate data has been used as a method to test for linearity or nonlinearity of biomedical functional near-infrared spectroscopy (fNIRS) signals observing brain activities. Throughout three different surrogate tests, the third-order autocovariance, the asymmetry due to time reversal and the delay vector variance, the dynamical response of brain activities through fNIRS biomedical signals is likely to be a nonlinear system.
