Abstract
Inspection time (IT) paradigms provide a measure of visual processing speed by establishing the amount of time required to accurately identify a visual stimulus. The most commonly used stimulus is a "pi" figure with differing leg lengths, which is presented for various durations (20-200 ms). Following presentation the stimulus is masked and participants choose which leg was longer. Previous research has indicated improved perceptual ability during movement preparation (Hagura et al. 2012) and execution (Tremblay and Nguyen 2010), which may be attributed to enhanced visual processing. The aim of the present experiment was to examine visual processing speed prior to and during performance of a motor task using an IT paradigm. Participants (n=28) performed the IT task under three conditions. In the no-movement (NM) condition, participants grasped a manipulandum handle while performing the IT paradigm. In the peak velocity (PV) condition, participants reacted to a go-signal by making a rapid 30-deg elbow extension movement to a target, with the IT stimulus presented at peak limb velocity. In the movement foreperiod (FP) condition, participants performed the same movement but the IT stimulus was presented prior to the go-signal. In all conditions the IT stimulus was randomly presented for between 15-105 ms and then masked for 400 ms. Contrary to expectations, IT performance was significantly poorer in the PV condition in comparison to both the NM and FP conditions, which did not differ. Collectively, these findings suggest that visuo-perceptual ability is not enhanced during movement preparation, and is diminished during movement production.Acknowledgments: Supported by NSERC and the Ontario Ministry of Research and Innovation and Science