AbstractAccording to the constrained action hypothesis, an internal focus of attention (FOA) results in a decrement in performance compared to an external FOA because it interferes with automatic movement control processes (Wulf, 2013). It is unknown whether this interference occurs during preparation of the motor command or during online control of the movement. Thus, the purpose of the study was to investigate the influence of FOA on the performance of a fast, ballistic movement, which reduces or eliminates the ability to use online control. It was hypothesized that if FOA influences the preparation of the motor command then an external FOA should result in better performance relative to an internal FOA. Participants completed two sessions consisting of 100 aiming trials each, involving a ballistic movement through one of five targets (20 cm from the home position along a circular arc) using a KINARM robot. Each session was completed using either an internal or external FOA (counterbalanced, separated by a minimum of 24 hours). When the target disappeared (go-signal), participants were to move “their thumb” (internal) or “the dot” on the KINARM handle directly below their thumb (external), as fast and accurately as possible directly through the centre of the remembered visual target without stopping. A virtual soft wall behind the targets assisted movement termination. Results revealed no difference in performance between FOA conditions, specifically no main effects of FOA were found for movement time, reaction time, error in the forward or horizontal planes, or resultant error (all p values > 0.05). These results indicate that FOA does not affect preparation of the motor command, and suggests that FOA primarily influences online control processes.
Acknowledgments: Supported by NSERC (A.N.C. & E.K.C.), SSHRC (B.M) & OGS (N.M.D)