Abstract
Performing goal-directed movements has been shown to increase resistance to visual illusions, possibly due to enhanced visual processing. An inspection time (IT) task can be used to measure visual processing ability by having participants identify the longer leg of an asymmetric "pi" figure that is presented for various times (15-105ms), and then immediately backward masked for 400 ms to prevent further processing. A previous experiment used an IT paradigm during production of a goal-directed movement, and contrary to predictions, found degraded visual ability. However, online visual feedback of the limb was not provided, which may account for this finding. Thus, the purpose of the present experiment was to examine whether provision of visual feedback during movement production would enhance performance in an IT task. Participants (n=12) performed an IT task under three conditions: no-movement, during production of a 30-deg targeted right arm extension movement without visual feedback, and during production of the same movement with online visual feedback. Results revealed a main effect for condition, F(2, 22) = 4.71, p = .02, whereby IT performance was significantly poorer in the movement with visual feedback condition compared to the no-movement condition. These results suggest that adding online visual feedback during movement execution while also completing an IT task may exceed the capacity of the visual system, and degrade IT task performance.Acknowledgments: Supported by NSERC and the Ontario Ministry of Research and Innovation and Science