Truesense EEG sensor measures Hypnotic Trance condition.

I’ve finally got around to posting the surprising results obtained at the Arthur Findlay College on the 6th May 2014.

Abrief demonstration of hypnotic trance was measured using the popularTruesense EEGsensor to determine if any significant EEG differences between normal and hypnotic trance state could be found. In past demonstrations apart from a slight increased signal amplitude at the low frequency (delta and theta) and decreased amplitudes of the alpha and beta activity nothing of significance was seen.

However on this occasion and for some reason yet to be identified the participant who volunteered to undergo the measurement and partake in the demonstration showed a large scale change in their brain activity on entering the hypnotic state.


The spectrogram clearly show normal and expected brain activity prior to performing the hypnotic trance (Hand drop induction) but when in hypnotic trance the participants brainwave adopts a regular pattern. Fourier analysis on the signal during this hypnosis period shows peaks at 8, 16, 24, 32, 40, 48, 56Hz (increments of 8Hz) which is rather puzzling.

It may be questioned whether the EEG sensor was malfunctioning during this period, however the spectrogram shows the brain activity clearly returning to normal immediately once the participant exited the hypnotic trance condition. Strange eh?

I’ve performed further tests to try an replicate this result e.g. poor skin contact, poor electrical connection, low battery charge, but so far I’ve been unable to obtain anything near similar results.

I suppose this is just one of those experiences we’ll have to leave open.

Info on the spectrogram:

The spectrogram is a pictorial representation of the brain activity being measured.

Time is shown going left to right with the brain frequencies shown bottom (delta) to top (beta). The colours represent the signal strength or intensity of the brain frequency at that specific time. Dark blue representing low intensity and red representing high intensity - note: white is off the chart!

Chris Connelly 2017