NNJ15ZSA001N-AGBR: APPENDIX G INVITES PROPOSALS TO INVESTIGATE WHETHER 30 MINUTES OF ARTIFICIAL GRAVITY PER DAY DELIVERED EITHER CONTINUOUSLY OR IN SIX FIVE MINUTE INTERMITTENT BLOCKS MITIGATES CHANGES THAT OCCUR IN A SPACEFLIGHT ANALOG ENVIRONMENT. WE HAVE RECENTLY COMPLETED A 70 DAY 6 HEAD DOWN TILT BED REST STUDY IN WHICH WE IDENTIFIED SPECIFIC BED REST INDUCED CHANGES IN BRAIN STRUCTURE BRAIN FUNCTION SENSORIMOTOR AND COGNITIVE PERFORMANCE. HERE WE SELECT THOSE THAT ARE SENSITIVE TO THIS SPACEFLIGHT ANALOG ENVIRONMENT AS OUTCOME METRICS FOR THE FOLLOWING AIMS: AIM 1) DETERMINE WHETHER 30 MINUTES PER DAY OF SUPINE CENTRIFUGATION +1GZ AT THE HEART IS EFFECTIVE AT MITIGATING NEUROCOGNITIVE DECLINES INDUCED BY 60 DAYS OF 6 HEAD DOWN TILT BED REST IN COMPARISON TO A CONTROL GROUP THAT IS NOT EXPOSED TO AG. AIM 2) DETERMINE WHETHER CENTRIFUGATION IS MORE EFFECTIVE AND BETTER TOLERATED AS A COUNTERMEASURE WHEN IT IS DELIVERED CONTINUOUSLY FOR 30 MINUTES OR IN SIX FIVE MINUTE SESSIONS SEPARATED BY BREAKS OF FIVE MINUTES EACH. OUR APPROACH UTILIZES CUTTING EDGE NEUROIMAGING TECHNIQUES AND A BROAD RANGING BATTERY OF SENSORY MOTOR AND COGNITIVE ASSESSMENTS THAT WE HAVE FOUND TO BE SENSITIVE INDICES OF BED REST AND IN SEVERAL CASES SPACEFLIGHT INDUCED PERFORMANCE DECREMENTS.