An assembly and system for collection and assessment of physiological data is provided. The assembly includes a physiological data acquisition module that may be used in combination with a head harness for the collection, recordation, storage and transmission of quality physiological data. The assembly integrates easy to use, self-applied electrodes in a user-friendly system resulting in less data artifacts than commonly seen in conventional methods and techniques for collecting physiological data. The assembly and system captures high-quality physiological data for display, storage, processing and analysis.