Relationship between Vestibular Inputs and Cerebral Blood Flow Response. Correlation between position (left panel) or velocity (right panel) and cerebral flow velocity (CFV) at the various frequencies. Changes in CFV were correlated to velocity only at the highest two frequencies for both tilt (TILT) and centrifugation (CEN). In contrast, changes in CFV were correlated to position at all frequencies for centrifugation. During tilt, changes were strongly correlated at 0.0625 & 0.125 Hz, with lower values at the higher and lowest frequencies. *, indicates significant difference from 0.5 Hz (P < 0.05); α, indicates significant difference from velocity correlation at that frequency (P < 0.05).