Abstract
How does resolution guide attention? Previous studies have shown that unique clarity captures attention (Enns & MacDonald, 2013; Loschky & McConkie, 2002; Peterson & Loschky, submitted; Smith & Tadmor, 2012). But, what about blur? Peterson et al. (2017) found unique blur weakly repelled attention towards nearby clarity, whereas unique clarity strongly captured attention. Are these results explainable by resolution being a search asymmetry? If resolution is a search asymmetry, then making resolution task-relevant should replicate Peterson et al.'s asymmetric findings. However, if both blur and clarity can be selected for and used to efficiently guide attention, then resolution is not a search asymmetry, but instead depends upon its task-relevance. Experiment 1 manipulated task relevance in a rotated L versus T visual search task while measuring eye movements and reaction times. Resolution's task-relevance was manipulated with instructions (Use Blur, Use Clarity, Do Not Use Unique Blur or Clarity, and No Instructions) and probability (in a set size of 6, Task-relevant resolution singleton at target 67% (4/6), Task-irrelevant resolution singleton at target 17% (1/6) = chance). The results showed unique blur was strongly selected for when task-relevant, but weakly repelled attention toward nearby clarity when task-irrelevant. Experiment 2 asked if resolution is preattentively available when task-relevant. In two conditions, participants either searched for a blurred or clear T, amongst T distractors of the opposite resolution with set sizes 2, 4, and 8. The target present RT x Set Size search slopes for both blur and clarity were < 1 msec/item, suggesting that both are processed preattentively and resolution is not a search asymmetry. Overall, the results suggest resolution's influence on attention is contingent upon its task-relevance. When relevant, both blur and clarity are efficiently selected for and strongly guide attention. When task-irrelevant, unique clarity strongly captures attention, while unique blur weakly repels attention towards nearby clarity.
Meeting abstract presented at VSS 2018