Preparation of saccade sequences and eye programming affect endogenous covert attention

Endogenous attention can be allocated in parallel to at least two saccade target locations of a planned sequence, but attentional resources are larger in the location of the first than the second saccade. The meridian effect that is observed in endogenous attention can be explained by eye programming, but it is not known how eye-movement preparation and eye programming can together affect endogenous attention during sequential saccades. We used a double-task paradigm to investigate this issue. In two experiments, we confirmed the relation between the preparation of sequential saccades and attentional selection and also showed that eye programming could eliminate deterioration of attentional resources in the second saccade location. The finding of the meridian effect in both the saccadic task and the target discrimination task additionally indicates the important role of eye programming in endogenous attention. The results were discussed in terms of the Premotor Theory of Attention.