Splitting the attentional spotlight? Evidence from attentional capture by successive events^*

* The data that support the findings of this study are openly available in Figshare at https://figshare.com/articles/Splitting_the_spotlight_Evidence_from_attentional_capture_by_successive_events/7855574.

ABSTRACT

Must attention be disengaged from a location before it can be moved to another? We addressed this question in four experiments. Participants searched for a target defined by its colour. The search display followed either one or two successive singleton cues that were expected to capture attention because they were in the target colour. We found a spatial benefit at the location of the first cue even though attention had been shifted to the location of the second cue. However, this benefit was smaller than when the second cue had been absent. These findings suggest that attention can be directed to a new location before it is entirely disengaged from its previous locus. We tested and rejected alternative interpretations, according to which this residual spatial effect resulted from occasional failures of attentional capture by the second cue, or from variability of the speed at which attention was shifted from one cue to the other. Taken together, our findings suggest that shifting attention from one location to another results in two simultaneous foci of attention for at least 300 ms. We discuss the possibility that the residual spatial benefits observed here may reflect pre-attentive tagging rather than parallel allocation of a limited resource to two separate locations.

KEYWORDS:

• Spotlight
• split attention
• spatial selection
• attentional capture
• spatial cueing
• contingent capture

Acknowledgement

Support was provided by the Israel Science Foundation (ISF) grants no. 1286/16 to Dominique Lamy. We thank Roi Keidar for his precious help in running the experiments.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

* The data that support the findings of this study are openly available in Figshare at https://figshare.com/articles/Splitting_the_spotlight_Evidence_from_attentional_capture_by_successive_events/7855574.

1 Note that the temporal interval between the second cue and the target rather than between the first cue and the target is the relevant interval to manipulate in order to test this prediction. Only after attention is shifted to the location of the second cue can it start to be deallocated from the location of the first cue.

2 We did not expect this manipulation to yield inhibition of return (IoR, Posner & Cohen, 1984), that is, delayed response latencies at the location of the fist cue after attention was shifted to the second cue, because IoR is typically observed with abrupt onsets and not with color singletons and with longer inter-stimulus, typically over 800 ms (e.g., Pratt, Sekuler, & McAuliffe, 2001 but see Priess, Born, & Ansorge, 2012, for evidence of IoR with color singletons using eye movements).

Additional information

Funding

This work was supported by Israel Science Foundation: [Grant Number 1286/16].