I laterally spy with my dominant eye


We recently reported that visual information gathered by the dominant eye is critical for online control (e.g., Manzone et al., submitted). Specifically, briefly presented target jumps were significantly corrected only when viewed by the dominant eye. Such an advantage may be due to the typical presence of the right hand in the right hemispace. To test this idea, participants performed reaching movements with the right hand while vision of the environment was restricted, using liquid-crystal goggles. Prior to each trial, participants fixated on a central cross. Their hand started either 12 cm to the right or left of that fixation point, with a binocular preview of the environment and target (30 cm away). The goggles were then occluded until the limb reached 1.0 m/s (Tremblay et al., 2013), which triggered a brief window of vision (i.e., 20 ms) providing visual information to the non-dominant eye, the dominant eye, or both eyes (i.e., binocular). During that window, the original (30 cm) or a jumped (27 cm) target was presented, with a 2:1 odds ratio. Analyses replicated our previous finding that participants exhibited significantly closer endpoints along the primary axis for the jumped target when vision was available to the dominant eye (i.e., dominant and binocular conditions). Critically, such corrections for the target jump via the dominant eye only occurred when movements began from the right starting position. As such, the results support the hemispatial functional advantage of the dominant eye and hand, for the online control of voluntary action.

Acknowledgments: Natural Sciences and Engineering Research Council of Canada (NSERC), Canada Foundation for Innovation (CFI), Ontario Research Fund (ORF).