Attenuation of size illusion effect in dual-task conditions.

We over-estimate or under-estimate the size of an object depending its background structure (e.g., the Ebbinghaus illusion).

Coordination of hitting movement revealed in baseball tee-batting.

Baseball batters must react to pitches delivered to different locations within the strike zone by modulating their movements. In tee-batting practice, such batters place a ball on a tee stand at a location, where they intend to hit the ball, assuming a particular pitch's trajectory. In the present study, we analysed three-dimensional movements in tee-batting to identify characteristics of the batters' intended impact locations across the strike zone, thereby investigating spatiotemporal features of movement modulation.

Does the size-illusion effect on prehensile movements depend on preview duration for visuomotor process?

Given that visual estimation of an object's size is affected by an illusory figure, the present study investigates the Ebbinghaus size-illusion effect on visuomotor performance within different preview durations for viewing an object (no preview, 300, 700, 1500, and 3000 ms) before initiating the movement. Twenty participants performed the following actions: (a) grasping the object and (b) matching the perceived object size with the finger aperture configuration as in the grasping task. The illusion affected the grasping aperture size only in the no- and 300-ms preview durations, while the matching aperture was affected across all preview conditions.

Prospective versus predictive control in timing of hitting a falling ball.

Debate exists as to whether humans use prospective or predictive control to intercept an object falling under gravity (Baurès et al. in Vis Res 47:2982-2991, 2007; Zago et al. in Vis Res 48:1532-1538, 2008).

A functional modulation for timing a movement: a coordinative structure in baseball hitting.

In baseball hitting, a powerful bat-swing needs to be produced by utilizing ground reaction force (GRF) and it should also be temporally coordinated relative to the flight of the pitch. The temporal organization of hitting movements associated with these task requirements was investigated by analyzing GRF during hitting slow and fast pitches. The timing of stepping with a front foot and shifting weight forward was modulated relative to the pitch's speed.

Control of ball-racket interactions in rhythmic propulsion of elastic and non-elastic balls.

Ball-racket interactions were investigated in a task where participants propelled a ball rhythmically into the air. The study contrasted two ball-racket conditions: (1) an elastic impact where the ball was able to rebound due to the elasticity of the colliding objects and participants bounced the ball, and (2) a non-elastic impact where the coefficient of restitution was zero and the ball did not rebound such that the participants had to throw the ball. The goal of the study was to contrast the situations where haptic information about the ball-racket interactions is either secondary (elastic bouncing) or becomes a primary factor for control (non-elastic propulsion).