FIG. 3.

EMG recordings were evoked by stimulating in the superior colliculus (1-s trains at 333 Hz with 5–100 μA). Timing and intensity is indicated above EMG traces. While descending through the superior colliculus, contralateral movement (left) begins at 4 mm below the brain surface, whereas ipsilateral movement (right) begins at 4.5 mm below the surface. Ipsilaterally evoked movement also persisted in deeper levels (down to 7.0 mm below the surface), whereas no contralateral movement could be evoked <6 mm. The schematic shows the stimulation sites.