Figure 4. Representative simultaneous stimulation and recording experiments.

(A) Repetitive stimulation of electrode 28 with 78 μA at 0.5 Hz (red lines, 10 times, identical parameters) induced an increased firing of the neurons surrounding this electrode. Only the last 4 stimulations were associated with the perception of a phosphene (see upper enlarged panel where “–” indicates no perception and “Y” indicates perception). (B) Repetitive stimulation of electrode 9 with 64 μA at 1 Hz induced an inhibition of the neurons surrounding the electrode that recovered after a few seconds. In each of these examples, the neural recording was obtained from the stimulated electrode. Red vertical bars indicate the stimulus times.