The main experiment consisted of a two-minute baseline period of walking with both belts at the same slow speed, followed by a 15-minute period with the belts at two separate speeds. While people were on the treadmill, researchers stimulated one side of the cerebellum to assess the impact on the rate of re-adjustment to a symmetric walking pattern.
Dr. Bastian’s team found not only that cerebellar tDCS can change the rate of cerebellum-dependent locomotor learning, but specifically that the anode speeds up learning and the cathode slows it down. It was also surprising that the side of the cerebellum that was stimulated mattered; only stimulation of the side that controls the leg walking on the faster treadmill belt changed adaptation rate.
“It is important to demonstrate that we can make learning faster or slower, as it suggests that we are not merely interfering with brain function,” says Dr. Bastian. “Our findings also suggest that tDCS can be selectively used to assess and understand motor learning.”