Crewmembers on long duration missions must remain productive in confined and crowded environments in which workloads are heavy, sleep is difficult, and where there is isolation from family and friends. Developing methods that allow crewmembers to deal with stress and other psychological challenges of long voyages will be critical to successful missions. The proposed neurodiagnostic device can be used to monitor and classify neurophysiological markers associated with decrements in behavioral state of the crew during exploration missions. The proposed device will be unobtrusive enough to allow mission operations to be performed during monitoring. The neurodiagnostic tool will allow autonomous operation, allowing crewmembers to operate the device without direction from the ground. The device will provide meaningful and actionable feedback to the crew. The system will also allow the ground-based medical staff to monitor the crew's behavioral health status during exploration missions. In addition to monitoring the behavioral health of the crew during space missions, the proposed device can be used to diagnose and treat various neurologic diseases and psychiatric illnesses. The multi-modal neurodiagnostic monitor can be produced at costs that are only about 50% higher than existing EEG but can provide significantly more meaningful diagnostic information. Some of the clinical applications for the device include: sleep monitoring, head injury and post-surgery evaluations, diagnosis of tumors and brain abscesses, diagnosis of multiple sclerosis, long-term epilepsy monitoring and psychiatric illness evaluations. In addition, the device, for the first time, allows ambulatory, multi-modality functional imaging of cortical activity. The system can be designed as ambulatory units for use in both clinical and non-clinical settings.