The use of a 'phantom scalp' to assess the possible direct pickup of mobile phone handset emissions by electroencephalogram electrode leads

A 'Phantom Scalp' was constructed from a conducting foam mat to form a layer under a 62-electrode electroencephalogram cap closely approximating the electrical properties of a human scalp. The mat was placed over a polystyrene manikin head to preserve a correct anatomical arrangement. Electrical signals were recorded with a Global System for Mobile (GSM) communications mobile phone handset in place against the side of the 'head'. Amplitude spectra were compared for three phone conditions: 'off', 'standby' and 'transmit'. At 217 Hz, significant differences were obtained between 'transmit' and the other two conditions, but no significant differences, were noted for the physiologically important range 0.5-30Hz. An anomalous difference was noted for one electrode in the range 30-45 Hz.