Evaluation of flexible cloth electrodes for electrodermal activity recording

Instrument selection for recording physiological data in flight studies requires careful attention to subject comfort and non-interference with aircrew activities. Several electrode types and recording sites may be used to examine electrodermal activity (EDA). Placement of electrodes on the foot minimizes interference with physical activity and reduces motion artifacts; however, use of conventional, hard-plastic-encased metal (PEM) electrodes within a flight boot can produce discomfort and pressure-induced artifacts.

When applied with proper electrolyte gels, thin, flexible, silver-impregnated cloth electrodes should acquire EDA signals qualitatively similar to those acquired using conventional, PEM electrodes.

EDA responses evoked by light flashes, auditory stimuli and valsalva maneuvers were recorded with cloth and PEM electrodes simultaneously from both feet of 4 male subjects. Performance of cloth vs. PEM electrodes and variability of signals recorded with the same electrode type were examined by placing pairs of selected electrodes on each foot of the subjects. Placements were balanced with respect to age and handedness of the subject and the number of trials with each electrode type placed on the left or right foot.

Qualitatively similar signals were recorded with cloth and PEM electrodes. Cloth electrodes showed more variability between electrodes of the same type.

For EDA recording, cloth electrodes can perform at least as well as PEM electrodes, making it practical to take advantage of the cloth electrodes' flexibility and lower profile.