Effects of Gaze Position on Touch Localization

Previous research has shown that the direction of gaze relative to the body affects the perceived location of touch, and has argued that these effects indicate that a gaze-centered reference frame is used for touch localization. In this dissertation I examine a discrepancy in the existing literature: why do different studies report opposite directions of effects when eye and head positions are manipulated separately? I resolve this discrepancy by showing that it is not due to whether eye or head position is manipulated (chapter 2) but is in fact due to the nature of the task (chapter 3). I also find that the effect occurs on the back of the body (chapter 4), a body part that is not normally in view and thus would be less likely to use gaze as a reference point. I test theories for why these effects occur (chapter 5), and find that results are compatible with the perceived location of a touch being attracted towards the location of gaze, at least for perceptual measures. When location was reported by pointing, an action-based measure, I find no effect of gaze direction on touch localization, suggesting that a gaze-independent reference frame is used for action. These behavioral results are complementary to recent neurophysiological and neuroimaging findings indicating that spatial locations are coded in a range of different reference frames, and indicate that gaze-related reference frames are behaviorally relevant in tactile localization.