| Summary: | The aim of this thesis was to investigate the process of control and learning of interceptive actions towards accelerating moving targets. The first chapter provides an introduction to the theoretical background adopted as well as the issues addressed in the thesis. The second chapter provides the general information about the method used in the experimental chapters. In chapter 3, the reported study investigated whether the usual bias in performance when intercepting accelerated targets (accelerated targets are timed too late and decelerating ones too early) changes over a period of practice. Participants were asked to manually hit moving targets and the results showed that after a few blocks trials they were able to intercept (positive and negative) accelerating moving targets as accurately as constant speed ones. Chapter4 further investigated the differences in performance when intercepting accelerated and constant speed objects by testing the hypothesis as to whether people are able to acquire internal model for interception. Participants were trained to intercept accelerating (exp.1) and decelerating (exp.2) targets in order to acquire an internal model for the arbitrary acceleration with which the targets were moving. Results indicated that, after a short period of practice, participants accurately intercept the targets under accelerated motion (i.e. acceleration and deceleration) and showed after-effects due to learning on trials where the motion was altered to constant, corroborating with the idea of internal models for interception. In Chapter 5, the experiment sought to investigate the effects on movement constraint in the interception of moving targets. Participants used a pendulum to intercept targets moving under constant and accelerated motion. Results showed that participant’s responses were earlier for slow targets and later for fast, which is inconsistent with the hypothesis of the use of an invariant perceptual variable for movement initiation. The final chapter provides a summary of the main findings and conclusions.
|
|---|
