Quantification of sensibility to conductivity changes in bipolar rheoencephalography

The authors' purpose is to quantify the rate of bipolar rheoencephalogram originated by changes in scalp and brain conductivities. They use a four-layer sphere model of the head, which is solved by numerical methods. Array of solutions obtained when brain and scalp conductivities change separately, shows that only 7% of the rheoencephalogram is caused by changes in brain conductivity.