Abstract
According to action-centered models of attention, there is a coupling between attention and response planning processes. Supporting these models, previous research has shown that reach trajectories deviate towards a distracting cue at short (<100ms) cue-target onset asynchronies (CTOAs) and away from the cue at longer CTOAs (>750ms). The deviations resemble the pattern of facilitatory and inhibitory reaction time (RT) effects seen in similar paradigms using keypress responses (e.g., Posner & Cohen, 1984). Here, we used 5 CTOAs (125ms intervals) ranging from 100-600ms to determine the relationship between trajectory and RT effects. Right-handed participants performed aiming movements to 3 possible target locations aligned horizontally to the participant following a non-predictive cue. Typical RT effects were found with facilitation to the cued location at the shortest CTOA and inhibition at later CTOAs. However, at the longest CTOA, RTs to the cued location and the right cue were similar. Trajectories deviated toward the right cue at the 100ms CTOA and then towards the left cue at the 225ms CTOA. Trajectories deviated away first from the right cue at the 475ms CTOA and then away from the left cue at the 600ms CTOA. Although the results are consistent with action-centered attention, the staggering of the trajectory deviations over right and left cues indicates that the timing facilitation and inhibition in the attentional and motor system may differ between right and left space.Acknowledgments: Research was funded by NSERC