Figure 8.

a) Parallel selection model where reach and saccade target selection occurs in parallel dedicated systems that do not interact with each other. b) Interacting selection model where selecting a reach-and-saccade movement depends on coordinating the activity of neurons across the reach and saccade systems. c) Common input model where target selection for reaches and saccades results from common input to the parietal reach and saccade systems from a third, effector-non-specific, selection system.