The exact mechanisms by which humans control the manual interception of moving targets are currently unknown. Here, we explored the behaviours associated with the spatial control for manual interception. The examined task required controlling a cursor to intercept moving targets on a touch screen. We explored the effects of target motion direction, curvature and occlusion on manual interception. We observed occlusion-dependent spatial errors and arrival times for curved and diagonal trajectories (larger errors and earlier arrival of the finger at its final position with longer occlusion. These effects were particularly apparent for targets moving away from screen centre at interception due to curve. In a follow-up experiment we showed that the outward curve effects on spatial errors were absent because the associated trajectories appears to move towards positions that participants could expect the target to never reach. Our analyses also revealed occlusion-dependent spatial errors for diagonal trajectories, which is well-known angle-of-approach effect. Follow-up experiments demonstrated that this effect was not due to the central initial cursor position acting as a visual reference point or the initial ocular pursuit. Most importantly, the angle-of-approach effect persisted in a judgment task. We thus conclude that this effect does not stem from online information-based modulations of movement speed, but from target information used to control aiming (i.e., movement direction). Moreover, processing for diagonal target motion appears to be biased towards straight downwards.
|Number of pages
|Journal of Experimental Psychology Human Perception and Performance
|Published - 27 Apr 2017