| While both perceptual and preferential decision-making share the underlying iterative process of sampling and integrating information, it is difficult to make direct comparisons between these two types of decisions because they have been studied under separate disciplines, each with its own distinctive techniques. Research in perceptual decisions has highlighted how covert attention improves behavioral performance in a variety of sensory tasks, from contrast sensitivity and orientation discrimination (Liu, Abrams, & Carrasco, 2009) to motion coherence (Liu, Fuller, & Carrasco, 2006), as it enhances the processing of early visual information. Yet it has also been established that overt, relative attention, as measured by gaze exposure, is highly correlated with preferential choice in value-based decision making (Bird, Lauwereyns, & Crawford, 2012; Krajbich, Armel, & Rangel, 2010; Krajbich & Rangel, 2011; Shimojo, Simion, Shimojo, & Scheier, 2003).;How do our higher-level intentions of being objective in perceptual choice versus being subjective in preference choice differentially impact choice formation? In this dissertation, I investigate how downstream decision processes, from information acquisition and evaluation to the eventual choice outcome, may be modulated by different task goals. In doing so, I explicate the role of selective attention in information search strategy, as it appears to have biasing effect in preferential but not perceptual choice. To compare choice formation in perceptual and preferential tasks, I used an experience-based paradigm that involved monitoring participants' eye movements as they chose between two rapidly updating options (fishing ponds). Specifically, participants were asked to look at the two ponds and choose the pond they would rather fish from (preference frame), or choose the pond which had more fish surfacing on average (perceptual frame).;Results indicate that participants' eye gaze shifts toward the more favored option just before choice. However, this gaze bias was reduced in the perceptual frame. Moreover, perceptual participants maintained good discrimination accuracy even when they acquired less information. In contrast, preference participants were more likely to pick the option viewed for a relatively longer time, especially when less information was obtained. Data from both tasks are well described by a diffusion model of evidence accumulation which compares and integrates stimulus information based on eye gaze location, indicating a qualitatively similar choice process even when the higher-order tasks goals were different. However, consistent with behavioral results, the modeling reveals that distinction between task goals lies in quantitative differences across cognitive parameters as perceptual choice was associated with a lower gaze bias and greater information valuation than preferential choice.;As it is expected that higher-order intentions are reflected in downstream choice processes, I sought to test if this differential impact of task goals depended on the ability to actively control information uptake. This was done by conducting a second study that directly manipulated stimulus exposure by presenting samples of information in a single continuous stream. Results indicate that perceptual and preference participants were equally susceptible to the gaze bias when they passively viewed the options. Together, these results highlight the importance of agency and voluntary control of relative attention during the processes of information search and valuation across perceptual and preferential choice. |
