Abstract
Attention is dynamic, constantly shifting between different locations. How do goal-driven expectations impact dynamic spatial attention? A previous study from our group (Dowd & Golomb, in press, Psych Science) explored object-feature binding when covert attention needed to be either maintained at a single location or shifted from one location to another. Participants received either one or two spatial cues on each trial, followed by an array of four colored and tilted bars. Participants were instructed to reproduce the color, orientation, and location of the bar in the most recently cued spatial location. Unexpectedly, on “Hold attention” trials where participants only received one spatial cue, they sometimes reported the features and location of a different, non-cued object. We posit that these correlated errors represent “lapses” in spatial attention, which are distinct from random guesses in that participants are reporting correctly-bound features of distractor objects—perhaps driven by the sampling of other locations in anticipation of a second spatial cue. To investigate whether these lapses are indeed anticipatory in nature, we conducted a new experiment where participants were assigned to one of three conditions: (1) “Non-Predictive Second-Cue”: a replication of the original experiment with intermixed Hold (single-cue) and Shift (double-cue) trials, where the second spatial cue location was not predictable (e.g., could be clockwise or counter-clockwise); (2) “Predictive Second-Cue”: intermixed Hold and Shift trials where the location of the second spatial cue (when present) was always clockwise; and (3) “Single-Cue-Only”. Lapses of spatial attention were measured by correlated errors wherein participants reported the features and location of the wrong object on Hold (single-cue) trials. Lapses were found on Hold (single-cue) trials in the Predictive and Non-Predictive conditions, but not in the Single-Cue-Only condition, suggesting that these spatial lapses are indeed anticipatory, induced by the expectation of making an attentional shift.
Acknowledgement: NIH R01-EY025648 (JG)