FIG. 1.

Schematic of the different conditions tested. A: auditory fast condition where 10 pacing metronome clicks are given at a 550-ms period, and then subjects continue at a remembered pace. B: auditory slow condition where 10 pacing clicks are given at a 1,500-ms period, and subjects continue at a remembered pace. C: visual fast condition where a pacing dot revolves 10 times around the circle at a period of 550 ms and then subjects continue at a remembered pace. D: visual fast condition with constant pacing dot at 550-ms period (i.e., the dot never disappears). E: visual fast imitation condition where the pacing dot revolves on an adjacent circle at a 550-ms period and never disappears. F: visual fast human imitation condition where pacing at a 550-ms period is done by a trained person (P) on an adjacent circle with a pacing dot.