Variable effects of pathologic scotomata on wave form of pattern-reversal visual evoked response.

Further experiments in healthy subjects have confirmed the characteristic but variable differential effect of experimental scotomata on the pattern evoked potentials. While the waveform changes associated with different pathological scotomata also showed considerable variability, certain features common to healthy and abnormal responses could be identified. These non-specific effects of scotomata on component amplitudes and distributions frequently result in spurious delays of wide-field responses and thus have important implications for the pathophysiological interpretation of abnormal responses.