VISUAL ATTENTION AND RT DISTRIBUTIONS 1 Location Cuing and Response Time Distributions in Visual Attention

The allocation of visual attention was investigated in two experiments. In Experiment 1 (n = 24), a peripheral cue was presented, and in Experiment 2 (n = 24), a central cue was used. In both experiments, cue validity was 90 % and the task was 4-choice target identification. RT distributions were collected for valid trials over 5 cue-target SOAs, and ex-Gaussian parameters were extracted. In both experiments, only the mean of the Gaussian component decreased as a function of cue-target SOA, which implied a strict time-axis translation of the distributions. Results were consistent with sequential sampling models featuring a variable delay in the onset of information uptake. VISUAL ATTENTION AND RT DISTRIBUTIONS 3 In location-cuing studies of visual attention, a particular location in the visual field is indicated (cued) by a marker, after which a target is presented. The most general finding from this type of study is that target identification or detection is faster and more accurate at cued (valid) than at uncued (invalid) locations (Cheal & Lyon, 1991; Jonides, 1981; Posner, 1980). A secondary finding is that the time interval between cue and target onset (stimulus onset asynchrony, or SOA) affects both response time (RT) and accuracy. Specifically, as SOA increases, identification RT generally decreases at valid locations and increases or remains constant at invalid locations (Remington & Pierce, 1984), whereas identification accuracy increases at valid locations and decreases or remains constant at invalid locations (Cheal & Lyon, 1991; Gottlob & Madden, 1998). The time signatures of these RT- and accuracy-SOA curves have been studied under a wide variety of stimulus and task demands (Cheal & Lyon, 1991; Cheal, Lyon &amp