1976 Volume 19 Issue 3 Pages 153-158
In ERA interchanged sound stimulus method was used. Apparats used was consisting of interchanged stimulus and EEG divided system and four channels computer.
Stimulus interchanged system were able to use four sound stimuli and these were presented to the patient one by one interchangably, simultaneously the EEG were divided to each of the four channels in the computer.
Using this method and instrumentation, the effect of changes in the psychologic state which might occur during the test, would be sampled evenly in each of the four responses averaged for each of the four different stimuli. Therefore we were able to compare each of the four averaged responses, and this method was applied for estimation of the response threshold and an objective test for the recruitment phenomenon.
