|
The
International Journal for Neuroscience.
1994 May;76(1-2):87-93.
Telles
S, Nagarathna R, Nagendra HR, Desiraju T.
Department of
Neurophysiology, NIMHANS, Bangalore, India.
Middle latency auditory evoked potentials were recorded in 18 male
volunteers with ages between 25 and 45 years, 9 of whom had more than 10
years of experience in "Om" meditation (senior subjects), whereas the
other 9 had no meditation experience (naive subjects). Both groups were
studied in two types of sessions.
(1) Before,
during, and after 20 minutes of mentally repeating "one" (control
session), and
(2) a similar
session, though with 20 minutes of mentally chanting "Om" (meditation
session). The senior subjects showed a statistically significant (paired
t-test) increase in the peak amplitude of Na wave (the maximum negative
peak between 14 and 18 ms) during meditation, while the same subjects
showed a statistically significant reduction in the Na wave peak amplitude
during control sessions. In contrast, the naive subjects had a significant
decrease in the Na wave peak amplitude during meditation sessions and a
nonsignificant trend of reduction during control sessions, as well. This
difference between senior and naive subjects was significant (two-way
ANOVA). There were no significant changes in short latency wave V or Pa
wave (the positive peak between the Na wave and 35 ms). The changes in the
Na wave suggest that both mediation on a meaningful symbol, and mental
repetition of a neutral word cause neural changes at the same level
(possibly diencephalic). However, the change could be in opposite
directions, and this difference could be correlated with differences in
the duration of experience in meditation between senior and naive
subjects.
|
