Off-components in response to brief light flashes in the oscillatory potential of the human electroretinogram

Amplitudes and implicit times of the several oscillatory potentials (OP's) in the human electroretinogram have been studied in relation to temporal, adaptive and spectral stimulus variables. The last of the OP-wavelets responds differently from the preceding ones; its implicit time shortens with increase in stimulus frequency or adaptive illumination, whereas that of the preceding OP's is prolonged or stays constant. Moreover, the last OP-wavelet is time locked with the stimulus offset, whereas the others are not. This can be confirmed by linear subtraction of responses to an isolated stimulus onset from responses to stimuli of variable durations. These results indicate, that the last oscillatory potential is related to the light offset and is presumably generated by the retinal off-elements described in single cell recordings.