A system for in vivo and transcranial stimulation of brain tissue of a subject may include at least one light source; a controller to control operation of the light source; a signal detecting unit and a processor configured to receive a signal from the signal detecting unit; analyze the signal and generate a feedback signal to the controller to control the light source until optimal results are obtained, wherein the detected signal is an electroencephalogram (EEG) signal, on which local peak frequencies are extracted and recorded periodically and repeatedly within a predetermined time frame before, during and after light stimulation, and the feedback signal is generated by comparing the local peak frequencies of before, during and after the brain stimulation to determine if brain synchronization occurs and sustains, and the feedback signal is generated.
METHOD AND APPARATUS FOR MEASURING BRAIN SYNCHRONIZATION