Modification of the paired H reflex through the transcendental meditation and TM-Sidhi program.

The paired H reflex, considered to be the electrically evoked counterpart of the monosynaptic stretch reflex, provides a measure of motoneuron excitability under a variety of experimental and clinical conditions. This study investigated the longitudinal effects of an advanced meditation program (the TM-Sidhi program) on the paired H reflex at nine delay intervals (50, 70, 100, 150, 200, 250, 333, 500, and 1000 ms). An experimental group of 14 subjects with no mental or motor disorders was instructed in an advanced TM program known as the TM-Sidhi program and the control group (N = 8) practiced the TM technique only. The amplitude of the paired H reflex was significantly facilitated in the experimental male subjects at intervals 100 through 250 ms, whereas the experimental female subjects and controls showed no significant change. These results extend previous studies showing distinct physiologic differences between subjects practicing these two programs and are of additional interest because they show that the H reflex can be modified in normal subjects.