Visual evoked nerve cerebral oxygen characteristics analysis based on NIRS-EEG

Visual evoked stimulation is an important method to study the response of optic nerve at the visual cortex. The visual cortex is closely related to the physiological state of the occipital lobe in brain. In the human, steady-state visual evoked potentials (SSVEP) and cerebral oxygenation changes, as measured by multi-modal of near-infrared spectroscopy (NIRS) and electroencephalography (EEG), are assessed to elucidate the relation between electrophysiological and haemodynamic responses to a checkerboard stimulus reversing. Further validation was done on ten healthy adults using a visual stimulation protocol to detect local hemodynamic changes and SSVEP component P100N135 amplitude. The experimental results show that there is a linear relationship between P100N135 amplitude and cerebral oxygenation concentrations in visual cortex. Within the 1-min stimulation period we find a decrease in P100N135-component amplitude, closely coupled to a decrease in the concentration of the oxyhemoglobin (HbO2) and an increase of the deoxygenated hemoglobin (HbR).It provides a new way to clinical brain function detection and analysis through the multi-modal NIRS and EEG.