Rhythmic wavelets of the positive off effect in the human electroretinogram.

The human electroretinogram (ERG), evoked with intense illumination, presents a sequence of rhythmic wavelets superimposed on the rising phase of the b-wave.' Similar rhythmic on wavelets are found in many ver­ tebrates and are labeled the "oscillatory po­ tentials." Studies of the nature of these oscillatory potentials" demonstrated their clinical importance." Other studies demon­ strated that the positive off effect is also di­ vided into multiple peaks in frog,* turtle, pigeon," and human." Because of tech­ nical and other problems resulting from their low amplitudes, the off effect and its subcom­ ponents have not been closely examined in the human. This paper demonstrates how multiple off effects in man are easily re­ corded, using intense stimuli, an averaging computer, and short-time constant amplifier.