Long-term Vipassana meditators sat in meditation vs. a control rest (mind-wandering) state for 21 min in a counterbalanced design with spontaneous EEG recorded. Meditation state dynamics were measured with spectral decomposition of the last 6 min of the eyes-closed silent meditation compared to control state. Meditation was associated with a decrease in frontal delta (1–4 Hz) power, especially pronounced in those participants not reporting drowsiness during meditation. Relative increase in frontal theta (4–8 Hz) power was observed during meditation, as well as significantly increased parieto-occipital gamma (35–45 Hz) power, but no other state effects were found for the theta (4–8 Hz), alpha (8–12 Hz), or beta (12–25 Hz) bands. Alpha power was sensitive to condition order, and more experienced meditators exhibited no tendency toward enhanced alpha during meditation relative to the control task. All participants tended to exhibit decreased alpha in association with reported drowsiness. Cross-experimental session occipital gamma power was the greatest in meditators with a daily practice of 10+ years, and the meditation-related gamma power increase was similarly the strongest in such advanced practitioners. The findings suggest that long-term Vipassana meditation contributes to increased occipital gamma power related to long-term meditational expertise and enhanced sensory awareness.

The effects of target tone frequency, presence of a masking stimulus, and subject sex on the auditory ERP were studied with an 'oddball' paradigm. P300 latency became shorter (about 15 msec) as the difference between the standard (1000 Hz) and target tone frequency increased (1500, 2000, 4000 Hz) but became longer (about 10 msec) with the presence of a white noise masking stimulus. Similar results were obtained for both the P3a and P3b subcomponents of the P300 potential. No significant differences between the adult male and female subjects were observed. The role of stimulus parameters in applied testing situations is discussed.

P300 latency from a simple auditory discrimination counting task was obtained along with a digit span memory task for a large group of neurologically normal subjects. Moderate significant negative correlations between the peak latency of the P3a and P3b subcomponents and total memory score were found, although no relationship was observed for other waveform component latencies and memory score. The data suggest that the P300 component of the event‐related brain potential may index individual variations in memory ability. Copyright © 1983, Wiley Blackwell. All rights reserved