Electrocortical Activity Prior to Unpredictable Stimuli in Meditators and Non-Meditators

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Plain English Summary

Can experienced meditators sense what's coming before it happens — not in their gut, but in their brain waves? That's what this study tried to find out. Researchers hooked up eight seasoned meditators (we're talking 3,000+ hours of practice, averaging over 20 years) and eight non-meditators to EEG caps that measure electrical activity across the scalp. Then they hit participants with random flashes of light and bursts of sound, chosen by a truly random number generator so nobody — not even the experimenters — could predict what was coming next. The results were striking. Non-meditators showed zero meaningful brain differences before different stimulus types. But the meditators? Five out of 32 brain channels lit up with significant pre-stimulus differences, mostly over the right side of the back of the head (the visual processing area, interestingly). When comparing meditators to non-meditators specifically before audio tones, nearly half the channels showed significant differences. The strongest effects appeared during the "free-running" task, where timing was completely random, eliminating any possibility of unconscious counting or anticipation strategies. This study came from the Institute of Noetic Sciences consciousness research program, funded by the Bial Foundation, with a tight-knit team of four researchers who frequently collaborate on similar work.

Actual Paper Abstract

Advanced meditators occasionally report experiences of timelessness, or states of awareness that seem to transcend the usual boundaries of the subjective present. This type of experience was investigated in eight experienced meditators and eight matched controls by measuring 32 channels of EEG before, during, and after exposure to unpredictable light and sound stimuli. The experiment postulated that if some aspect of consciousness extends beyond the present moment, then prestimulus electrocortical signals should differ depending on stimuli that were about to be selected by a truly random process, and that if such experiences were catalyzed through meditation practice, then prestimulus differences should be more apparent in meditators than in nonmeditators. Each of the 32 EEG channels was baseline adjusted on each trial by the electrical potential averaged between two- and one-second prestimulus, then for each channel the average potential was determined from one-second prestimulus to stimulus onset. The resulting means across subjects in each group were compared by stimulus type using randomized permutation procedures and corrected for multiple comparisons. Within the control group, no EEG channels showed significant prestimulus differences between light versus sound stimulus conditions, but within the meditator group ﬁve of 32 channels resulted in signiﬁcant differences (P .05, two tailed). Comparisons between control and meditator groups showed significant prestimulus differences prior to audio tone stimuli in 14 of 32 channels (P .05, two tailed, of which eight channels were P .005, two tailed). This outcome successfully replicates effects reported in earlier experiments, suggesting that sometimes the subjective sense of awareness extending into the future may be ontologically accurate.

Research Notes

IONS presentiment study using EEG rather than autonomic measures. Meditators showed prestimulus brain activity differentiation that controls did not, with effects concentrated in the free-running task where anticipatory strategies are eliminated by random ISI. Part of the IONS consciousness research program; all four authors (Radin, Vieten, Michel, Delorme) appear as co-authors across multiple IONS papers in this library. Bial Foundation funded.

Eight experienced nondual meditators (≥3,000 hours practice, mean 20.8 years) and eight matched nonmeditator controls were tested with 32-channel EEG while exposed to unpredictable light and sound stimuli selected by a truly random Zener-diode RNG. Within the control group, no EEG channels showed significant prestimulus differences between stimulus types. Within the meditator group, 5 of 32 channels showed significant prestimulus differences (P < .05, two-tailed, FDR corrected), primarily over right occipital regions. Between groups before audio tones, 15 of 32 channels were significant at P < .05 (8 at P < .005). The free-running task (random ISI, no timing cues) showed stronger effects than the on-demand task. Published in Explore 2011; 7:286-299.