Purpose: In real life, divergence is frequently combined with vertical saccades. The purpose of this study was to examine the initiation of vertical and horizontal saccades, pure or combined with divergence.
Methods: We used a gap paradigm to elicit vertical or horizontal saccades (10 degrees), pure or combined with a predictable divergence (10 degrees). Eye movements from 12 subjects were recorded with EyeLink II.
Results: The major results were (i) when combined with divergence, the latency of horizontal saccades increased but not the latency of vertical saccades; (ii) for both vertical and horizontal saccades, a tight correlation between the latency of saccade and divergence was found; (iii) when the divergence was anticipated, the saccade was delayed.
Conclusion: We conclude that the initiation of both components of combined movements is interdependent.