The Neural Control of Visually Guided Eye Movements
D. Temporal Factors in Visually Guided Saccadic Eye Movements

2. The brain structures involved in express saccade generation.

The role of various brain structures in the generation of express saccades has been studied predominantly by making selective lesions. As already shown earlier (Figure 9, this section) when the posterior system for the generation of visually guided eye movements is disrupted by lesions of the superior colliculus, express saccades are eliminated. By contrast, when portions of the anterior system are disrupted, express saccades continue to be generated. The upper panel of Figure 43 shows this for an animal in which the medial eye fields had been removed and the lower panel when both the medial and the frontal eye fields are missing. Express saccades are generated in all cases.