RESULTS

Evoked potentials were recorded in different periods of the test sessions conducted on subjects before they were initiated into pranayama training-

Peaking latencies and amplitudes of the Na and Pa waves recorded in the subjects before they were trained in pranayama, were not observed to be significantly changing (matched pairs t-test) in the three successive time periods (PEC, ECC, ECP) of a test session (Fig. 2). This check was done to know whether there could be any time effect, or sitting effect, on the evoked potentials recorded in successive time periods of a session. The amplitude of Na wave (mean + S.D., 10 subjects) was 0.86 + 0.3 mV in the PEC condition, 0.90 + 0.44 mV in the ECC condition and 0.81 + 0.65 mV in the ECP condition; of the Pa wave was 0.66 ± 0.30 mV in the PEC condition, 0.81 ± 0.35 mV in the ECC condition and 0.85 ± 0.45 mV in the ECP condition.

The latencies (meman + S.D., 10 subjects) of the 3 waves were as follows: Na wave had 17.2 + 1.54 ms in PEC state, 16.9 ±1.63 ms in ECC state and 17.0 ± 0.96 ms in ECP state; Pa wave had 26.9 ± 2.12 ms in PEC state, 27.2 ± 2.21 ms in ECC state and 27.2 + 2.02 ms in ECP state.

Evoked potentials recorded in different periods of pranayama sessions conducted after about 21 months of training and experience in pranayama.

The Na wave-peaking amplitude (average of 10 subjects) recorded during pranayarna state (PR) was significantly higher (by 108%) than that of the corresponding pretraining period (ECC, Table 1, Fig. 2). The value of post pranayama period (ECP) was not significantly different from that of the pre pranayama period (PEC).

The peaking latency of the Na wave of PR was not different from that of PEC, but was significantly less (by 9%) than that of ECC (Table.11, Fig. 2).

Analysis of variance test showed significant alteration of Na-wave amplitude in pranayama (Table iii), but not so for latency (F(2,27) 2.51, P(0.09). Analysis of Na wave peaking amplitudes done separately for ujjayi and bhastrika subjects showed a more significant alteration during ujjayi than during bhastrika compared to pre-pranayama periods with paired t-test (Table III), but ANOVA could not show adequate significance of the alterations probably due to small sample sizes.

The peaking amplitude and latency of the Pa wave were not significantly altered in pranayama compared to the immediately preceding baseline values of PEC state (Tables 1 and II). Their values of the period PR were also not significantly different from those of corresponding periods (ECC) of control sessions conducted before pranayama training. Also there were no significant differences in group averages of the 10 subjects for the 3 waves of PEC periods recorded before the subjects were trained in pranayama and after about 21 months of practice.
 

TABLE

No differences in wave changes between the two types of pranayamas
There were no significant differences in the peaking arnplitudes and latencies of the waves recorded during the two types of pranayarnas, viz., in the ujjayi and bhastrika groups (Student’s t-test). Further, the trend of increase of Na wave amplitude, and a reduction in its latency was generally observed during both types of pranayama practices. Hence the result of the 10 subjects were averaged together.

No alterations of the Na waves during period of attention to respiration in untrained subjects.
AEP-MLRs of a group of ten subjects untrained either in pranayama or in concentration, recorded during attention focussed on their unregulated tidal breathing and sensing the accompanying air flow through the nose, revealed no statistically significant (paired t-test) difference in the Na and Pa waves compared to those of the pre-attention baseline periods of the test sessions, repeated thrice in each subject. The Na wave peaking latencies (ms mean + S.D. for 10 subjects) for the pre, during and post periods respectively were: 16.58 +1.57, 16.80 + 1.25, 16.56 + 1.52. The Na-wave peaking amplitudes (µV mean + S.D.) for the pre, during, and post periods, respectively were: 1.08 + 1.08, 0.83 + 0.73, 0.83 + 0.56, The usual trend of amplitude change in the subjects was towards reduction during the period of attention, contrary to the trend of increase occurring during pranayama.

TABLE 2