Abstract
The redundant signals effect is characterized by shorter response times (RT) when two targets are present than when only one target is present. Previous work on the redundant signals effect has employed specific targets; for example, participants might be asked to press a button every time they see the number "2." The purpose of the current study was to determine whether or not the redundant signals effect extends to categorical targets; for example, asking participants to press a button every time they see any number. Toward that end, participants performed a go/no-go task in which they pressed a button every time they saw a number on a computer screen. Each trial contained two stimuli subtending 1° by 1° visual angle and placed 3° above and below the center of the display. On 50% of the trials, both stimuli were letters (no-target condition). On 25% of the trials, one stimulus was a letter and one stimulus was a number (one-target condition), and on 25% of the trials, both stimuli were numbers (redundant-targets condition). Accuracy did not significantly differ between the redundant-targets (almost 100% accuracy) and single-target conditions (~99% accuracy, p = .165). RT was faster in the redundant-targets condition (~461 ms) than in the single-target condition (~509 ms, p < .001). The results indicate that the redundant signals effect occurs even when participants search for a category of targets. Previous studies have suggested that redundant signals can increase the speed of early visual processing; our findings suggest that redundant signals can also increase the speed of processing at the categorical level.
Meeting abstract presented at VSS 2016