[The visual evoked response at the onset of structural movement]

Stimulation by means of moving the structure in the visual field is used to produce visual evoked responses (VER) only rarely. The authors attempted to verify the fact how VER to the movement depended on some stimulation parameters and to compare them with VER to the most frequently used stimulation method, i. e. reversal. Horizontally moving black and white vertical stripes were used with special frequency 2.3 cycles/deg on the screen. It was found that at least 3s interval between two stimuli (between the end of the preceding and onset of the following movements) was necessary and sufficient period of the moving was about 100 ms. Resultant VER are then a reaction on the onset of the movement and are characterized mostly only by marked negative peak with latency being 140 to 200 ms. Opposite to reversal VER, those to the onset of the movement were obtained just in 87.5% of the persons examined (n = 40), in five cases, however, the response to the onset of the motion was higher than that to reversal VER amplitudes were in the latter case highest in the unipolar lead from the right occipital region with the rate of the structure movement being 42 to 84 mm/s.