Abstract
Behavioral evidence is presented to support the claim that cuing can improve perceptual performance, using a measure that is not confounded by response bias. We used an orientation matching task to gauge the quality of participants' visual percepts. Participants (N = 20) were instructed to maintain focus on a central fixation cross while an exogenous cue and a randomly rotated Gabor patch stimulus were briefly presented on a screen. Participants then rotated a line to match the orientation of the stimulus. Accuracy was emphasized and auditory feedback was provided. Stimuli were presented left or right of center, and squares around those stimulus locations served as cues. Twenty percent of cues were neutral (cue on both sides), 40% were valid, and 40% were invalid. There were five blocks of 150 trials each. Stimuli appeared 60 ms following cue onset and remained on the screen for 60 ms. The response line appeared 300 ms after stimulus offset. Validly cued trials (mean error 10.3 degrees) were more accurate than invalidly cued trials (11.2 degrees), with neutral trials intermediate (10.6 degrees). Though participants were instructed to focus on accuracy, there was also a robust effect of cuing on response time. Judgments for validly cued stimuli (mean response time 846 ms) were reported more quickly than neutral trials (878 ms), and neutral trials were faster than invalidly cued trials (916 ms). Our accuracy results can be explained neither by response bias nor perceptual bias. We interpret our results to indicate an effect of cuing on perceptual quality.