THIS PROPOSAL ADDRESSES THE RISK OF ADVERSE BEHAVIORAL CONDITIONS AND PSYCHIATRIC DISORDERS AND THE NEED TO IDENTIFY AND VALIDATE COUNTERMEASURES AND EFFECTIVE METHODS FOR MODIFYING THE HABITAT VEHICLE ENVIRONMENT THAT PROMOTE INDIVIDUAL BEHAVIORAL HEALTH AND PERFORMANCE DURING EXPLORATION CLASS MISSIONS BMED1 BMED7. WE PROPOSE TO INVESTIGATE THE EFFICACY OF PHYSICAL EXERCISE USINGA CYCLE ERGOMETER COMBINED WITH AN INTERACTIVE VIRTUAL ENVIRONMENT HYBRID TRAINING AS A COUNTERMEASURE FOR AUGMENTING SENSORY STIMULATION DURING LONG DURATION SPACE MISSIONS. THIS COUNTERMEASURE WILL COMBINE VALIDATED TOOLS AND VR TECHNOLOGIES IN A NEW WAY TO REVEAL THE FULL POTENTIAL OF HYBRID TRAINING AND TAKE INTO ACCOUNT A KEY NEEDS THAT FULFILL SENSORY STIMULATION B HEDONIC ADAPTATION A REDUCED AFFECTIVE RESPONSE TO STIMULI WITH CONTINUED OR REPEATED EXPOSURE C DELIVERY SCHEDULE AND DSIZE MASS AND VOLUME REQUIREMENTS. WE PLAN TO INVESTIGATE A CREW OF N 9 DURING TWO 12 14 MONTH ANTARCTIC WINTER OVER MISSIONS IN NEUMAYER STATION TOTAL N 18. WE WILL INVESTIGATE BOTH IMMEDIATE AND LONG TERM BENEFITS OF HYBRID TRAINING. OUR PRIMARY OUTCOMES ARE NEUROSTRUCTURAL AND NEUROFUNCTIONAL CHANGES ASSESSED WITH FMRI AND COGNITIVE PERFORMANCE ASSESSED WITH THE COGNITION TEST BATTERY AND A VIRTUAL MAZE. WE WILL ALSO ASSESS BIOCHEMICAL MARKERS OF STRESS AND NEUROPLASTICITY OBJECTIVE MEASURES OF SLEEP WAKERHYTHMICITY AND SLEEP STRUCTURE SUBJECTIVE SYMPTOM REPORTS AND GROUP COHESION WITH UNOBTRUSIVE PROXIMITY MEASUREMENTS AS ADDITIONAL OUTCOMES THAT WILL PROVIDE INSIGHTS INTO MECHANISMS AND CONSEQUENCES OF THE OBSERVED STRUCTURAL AND FUNCTIONAL BRAIN CHANGES AND THEIR REVERSIBILITY BY HYBRID TRAINING. THESE DATA WILL BE COMPARED TO HISTORIC CONTROLS FROM NEUMAYER STATION ANDOTHER ANTARCTIC STATIONS CONCORDIA HALLEY SPACE ANALOG ENVIRONMENTS MARS500 AND THE ISS. AT THE END OF THE PROJECT WE WILL HAVE A MUCH CLEARER UNDERSTANDING WHETHER AND TO WHAT EXTENT THE DETRIMENTAL EFFECTS OF ICE ENVIRONMENTS ON NEUROPLASTICITY AND BEHAVIORAL HEALTH CAN BE MITIGATED BY HYBRID TRAINING.