Abstract
In this study, the encephalographic (EEG) correlates associated with memory guided reaching were examined. Participants performed aiming movements using a stylus on a graphics tablet with visual stimuli projected onto a mirror positioned above the aiming surface. For the experimental protocol, individuals were first provided with a cue followed by a brief preview of a target. The cue was indicative of the delay between the offset of the target preview and the imperative stimulus to move (i.e. 2 s or 5 s delay); and also whether the target would reappear when the imperative stimulus was presented (i.e. FV or NV). Event related brain potentials associated with target encoding; the expectancy of movement onset; and visually guided versus memory guided reaching were examined. Kinematic analyses were also used to examine the behavioural manifestations of the aiming movements. Results from the EEG analysis revealed a modulation of brain activity based upon the expectant delay between the target preview and movement initiation, which was irrespective of the visual condition. The corresponding behavioural analyses revealed similar results to previous memory guided reaching experiments (e.g. Elliott & Madalena, 1987), however it appeared that FV movements with a 5 s delay were also compromised in some respects. In all, the time from the initial encoding of the target to the impetus to move, may have larger implications in both memory and visually guided reaches than previously thought.Acknowledgments: NSERC