Abstract:
In three experiments we investigated effects on attention of peripheral landmark cues, that predicted a target at the same location, and counter-landmark cues, that predicted a target at a different location. In all three experiments, the delay between cue and target onset was very brief (66ms), and participants were not informed of the cue-target relation. On trials where cue and target appeared at the same location, simple response times (Experiment 1) and eye movements (Experiment 2) were faster on valid (landmark) compared to invalid (counter-landmark) trials. This effect was apparent early in practice. On trials where cue and target appeared at different locations, valid (counter-landmark) and invalid (landmark) trials did not differ. In Experiment 3 neutral cue trials were introduced. Here, on trials where cue and target appeared at the same location, eye movements were launched more rapidly on valid compared neutral trials, which did not differ from invalid trials. That is, the rapid effect of landmark cues on eye movements can be characterised as benefit without cost. Again, this effect was apparent early in practice, and was independent of awareness of the cue-target relationship. We propose that rapid movements of attention can be viewed as a form of visually guided action, controlled by rapid, non-conscious encoding in the dorsal visual stream. This work was supported by the Marsden Fund of New Zealand.
