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Abstract (number of words):141 (max. 150

Eye movements during rapid pointing under risk,” Vision Res

Abstract We recorded saccadic eye movements during visually-guided rapid pointing movements under risk. We intended to determine whether saccadic end points are necessarily tied to the goals of rapid pointing movements or whether, when the visual features of a display and the goals of a pointing movement are different, saccades are driven by low-level features of the visual stimulus. Subjects pointed at a stimulus configuration consisting of a target region and a penalty region. Each target hit yielded a gain of points; each penalty hit incurred a loss of points. Late responses were penalized. The luminance of either target or penalty region was indicated by a disk which differed significantly from the background in luminance, while the other region was indicated by a thin circle. In subsequent experiments, we varied the visual salience of the stimulus configuration and found that manual responses followed near-optimal strategies maximizing expected gain, independent of the salience of the target region. We suggest that the final eye position is partially pre-programmed prior to hand movement initiation. While we found that manipulations of the visual salience of the display determined the end point of the initial saccade we also found that subsequent saccades are driven by the goal of the hand movement

Decision Making and the Brain, Elsevier, in preparation. Corresponding Author:

Acknowledgments: We thank Paul Glimcher for his comments on an earlier draft of this manuscript. This work was supported by the Deutsche Forschungsgemeinschaft (Emmy-Noether-Programme; grant TR 528/1-3) and the National Institutes of Health (grant EY08266). Our survival depends on our ability to act effectively, maximizing the chances that we achieve our movement goals. In the course of a day we make many movements, each of which can be carried out in a variety of ways. Shall I reach for that wine glass quickly or slowly? Approach from the right or left? Movement planning is a form of decision making as we choose one of many possible movement strategies to accomplish any given movement goal. It is important for us to make these “motor decisions ” rapidly and well. In this chapter, we consider how movements are planned and show that a certain class of movement-planning problems is mathematically equivalent to a choice among lotteries in decision-making under risk or ambiguity (see also Trommershäuser et al., 2006a). This analogy allows us to examine movement planning from a new perspective, that of the ideal economic movement planner. It also allows us to contrast how we make decisions in two very different modalities, planning of movement and traditional economic decision making