Active conditions
CONTRACTION
During Active Exteroception, participants reported on the expansion and contraction of the circle on the screen, which again was set to pulse at participants’ in-scanner respiratory frequency. During Active Interoception, participants reported on inhalations and exhalations by making button box key presses with their right-hand index and middle fingers respectively. The circle on the screen expanded and contracted with these key presses, approximating the frequency of circle movement during Passive Exteroception. During Active Matching, participants reported on the expansion and contraction of the circle as in Active Exteroception, while synchronizing their inhalation to the circle’s expansion and their exhalation to the circle’s contraction.