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Blaine Tomkins


The goal of this study is to examine how individuals use perceptual, cognitive, and motor processes when making speeded decisions for visual stimuli. Participants performed a speeded choice decision task for simple shapes presented for a short duration (20 ms) or a longer duration (80 ms) to either the left or right side of a central fixation. In Experiment 1, participants pressed a key positioned to the right for “square” stimuli and a key positioned to the left for “circle” stimuli, effectively creating both location-congruent and location-incongruent stimulus-response mappings. In Experiment 2, response keys were aligned vertically rather than horizontally. Results for both experiments showed a duration x response mapping interaction effect, with faster correct responses when the stimulus was on the same side as the response key. However, this effect was only observed on short duration trials. These findings suggest when perceptual information is poor, individuals rely more on spatial-motor information to make quick decisions. In contrast, when perceptual information is strong, individuals rely less on spatial-motor information. These findings also show that location-congruency biases are modulated by the perceptual quality of stimuli.