The interpretation of the electroencephalographic signal is often limited to the assumption that the electrode placed directly above the source of the signal detects the largest potential, whereas more distant electrodes detect smaller potentials. However, in certain cases such interpretation can be misleading. The modern approach to interpreting the electroencephalographic signal makes use of dipole generators, whereas this signal recorded on the scalp can be understood much better with the help of the solid angle concept. The concept is very intuitive as the potential is proportional to the solid angle under which one ‘views’ the activated cortical surface from a certain point on the scalp. The solid angle concept is useful to explain the differences in the EEG signal when cerebral sulci or gyri are activated and can be applied to the monopolar as well as bipolar EEG records.