The Utility of Vision During Action: Multiple Visuomotor Processes?

ABSTRACT

Recently, D. Elliott et al. (2010) asserted that the current control phase of a movement could be segregated in multiple processes, including impulse and limb-target regulation processes. The authors aimed to provide further empirical evidence and determine some of the constraints that govern these visuomotor processes. In 2 experiments, vision was presented or withdrawn when limb velocity was above or below selected velocity criteria. The authors observed that vision provided between 0.8 and 0.9 m/s significantly improved impulse regulation processes while vision provided up to 1.1 m/s significantly increased limb-target regulation processes. These results lend support to D. Elliott et al. and provide evidence that impulse regulation and limb-target regulation can take place at different velocities during a movement.

Keywords:

• goal-directed
• online control
• pointing
• vision

ACKNOWLEDGMENTS

This research was supported by the Natural Sciences and Engineering Research Council of Canada as well as the Canada Foundation for Innovation and the Ontario Research Fund.

Notes

1. Note that a simple t test conducted between VHigh and VLow R ² values at 75% of MT did yield a significant difference (p < .05).

2. More liberal contrasts performed using paired t tests suggest that the vision and velocity criteria interaction can also be explained by lower R ² values in VHigh than VLow at the 0.03 m/s velocity criterion (p = .02) but higher R ² values for VHigh compared to VLow at the 1.1 and 1.2 m/s velocity criteria (ps = 0.05 and 0.003, respectively).

3. While R ² values were higher in VHigh compared to VLow conditions at 25% of MT, such a result should be taken with caution because the associated MTs were also different.