Increased proportions of sensed presences and occipital spikes with 1- and 10-msec. point duration of continuous 7-Hz transcerebral magnetic fields.

To test the hypothesis that the numbers of "sensed presences" induced by the application of weak (1 microTesla) magnetic fields over the right hemisphere was subject to an optimal time of presentation, digital-to-analogue computer generated 7-Hz sine-waves were applied with point ("pixel") durations of 1, 3, 5, 7, 10, or 20 msec. for 5 min. each in a sequential counterbalanced order for six subjects. The proportion of numbers of sensed presences reported along the subjects' left sides and the proportions of electroencephalographic spikes over the occipital regions were greatest when 1- or 10-msec. point durations were employed. These results indicate that the specific duration of each successive field strength composing a complex sequence should be considered when designing optimal configurations for intercalating with neurocognition.