Can deployment of attention be strategically controlled?

Abstract

The main goal of the experiment was to test whether deployment of attention could be strategically controlled. Subjects viewed five-letter arrays. Each array included a letter unique in shape (i.e. target). One of the letters in each array (target or non-target) also differed from other letters in color or in position in relation to the array. That letter will be referred to as a feature singleton. The probability ratio of the feature singleton being the target or a non-target letter was varied throughout three experiments. The ratios were (1) 0.5 (target): 0.5 (non-target); (2) 0.2 (target): 0.8 (non-target); (3) 0.8 (target): 0.2 (non-target). Subjects in all three experimental conditions deployed serial processes, but failed to maintain complete intentional control during the course of the search.