The present invention is a portable non-invasive system, apparatus and method for performing light therapy or photobiomodulation upon the brain tissues through the skull and/or nostrils of a living mammalian subject for the medical purpose of stimulating the brain in-vivo. The present invention utilizes the transcranial and/or intranasal pathways as points of anatomic access and follows established principles for the conceptual approach that irradiation of the brain tissue with low level light energy of certain fixed parameters would achieve major therapeutic effects in-vivo.
