Signal processing of brain activity with ant colony optimization and wavelet analysis using near infrared spectroscopy

Abstract

Signal processing of brain activity poses challenges to various researchers from different areas, including medical, biomedical, and engineering researchers. Taking the benefits from rapidly developing higher technologies, the outcomes of the research into brain activity have made great progresses. In this paper, investigations of brain activity are made from experimental works, with optical flow based on spatiotemporal analysis and wavelet with near infrared spectroscopy (NIRS). Ant colony optimization (ACO) algorithm is employed for obtaining the distributions of the intensity of the targeted image. The major outcomes of our research are the following five items: (1) optical flow is a proper technology for the investigation of brain activity based on NIRS; (2) the results of the temporal domain, spatial domain, and wavelet domain support each other through experimental results; (3) our wavelet analysis offers the most brain activity, defined as targeted image; (4) the details of the intensity distribution on the targeted image show the most significant brain activity via ACO; (5) we can clearly observe, via our algorithm technology, the existence of the so-called dominant channel (DC) based on spatiotemporal analysis and it plays a critical role in brain activity. The spatial distribution of the origin of cortical activity can be described by hemodynamic response in the cerebral cortex after evoked stimulation using near infrared spectroscopy. Further application of this research is expected in the next step research outcomes.