KeywordsPerceptual Decision Making
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PublisherThe University of Arizona.
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AbstractPerceptual Decision Making involves making a simple decision about some feature of a perceptual stimulus. How do different contextual influences change the underlying dynamics of this task? Here I use the Clicks task, a simple perceptual decision-making task where participants must report which side they heard more clicks, in order to study how different contextual influences can shape the underlying dynamics of this decision-making process. This task is subject to a number of different suboptimalities which can drive errors, such as side bias, integration shape, choice kernel, reinforcement learning, and noise. Here I address how various contextual influences can modulate these suboptimalities in order to change decision-making behavior. In the first study, I show that when participants are under higher motivation to perform the task accurately, noise in the decision process is subject to rapid modulation in order to achieve higher performance. However, no other suboptimalities were modulated in order to achieve this higher performance. The second study aims to find other sources of contextual influence that can modulate the other suboptimalities, such as the integration shape. Results show that through changing the underlying statistics of the stimulus, participants can indeed modulate their integration shape, or the way they weight information over time, to match these stimulus statistics. These two studies provide evidence that noise in the decision process, and integration shape are two underlying dynamics of the decision process that are subject to modulation. Future research can address further contextual influences that may be able to modulate the remaining suboptimalities such as side bias, reinforcement learning, and choice kernel.
Degree ProgramGraduate College