Relationship between the electroencephalogram and the rheoencephalogram in the normal young adult

The REG technique permitting an estimation of the grey matter flow was applied in conjunction with the simultaneous recording of the EEG analysed by the SULG manual method with 21 normal adult subjects. A relationship was established between the REG index and the EEG frequency index in a resting situation with eyes closed. An increase of the REG index was observed when the eyes were open, for looking at a picture and during a test of visual attention. At opening of the eyes a delay is observed between the desynchronisation of the EEG and the increase of the REG.