Results of Exp. 1 ([https://osf.io/aqkzh/][1]) revealed that 14.6 ms of continuous intra-saccadic object motion increased the proportion of secondary saccades made to the post-saccadic location of the initial pre-saccadic target relative to a condition in which this continuous motion was substituted by a blank of equal duration. In addition to that, secondary saccade latencies to the target were reduced.
While the result shows that intra-saccadic motion (and motion streaks specifically) facilitated secondary/corrective saccades, it remains unclear why this is the case. In the previous experimental design, motion streaks not only always connected pre- and post-saccadic target locations, but also always carried the surface feature of the target. As a consequence, the facilitation may have occurred due to spatiotemporal continuity, earlier availability of surface features, or both. In a 2x2 within-subject design, we will now orthogonally manipulate motion streak validity (to the target/valid or distractor/invalid location) and surface feature validity (target/valid or distractor/invalid features during motion). This should allow us to answer the question whether spatiotemporal continuity produced by motion streaks is feature-selective.
We hypothesise that valid motion streaks - irrespective of surface features - cause an increase of secondary saccade rate to the target, as well as a reduction of secondary saccade latency when saccades are made to the target. Similarly, invalid motion streaks, thus connecting pre-saccadic target and post-saccadic distractor locations, should have the opposite effect, relative to the neutral/no-streak condition.
[1]: https://osf.io/aqkzh/