MENTALLY SIMULATED MOVEMENTS IN VIRTUAL-REALITY - DOES FITTS LAW HOLDIN MOTOR IMAGERY

This study was designed to investigate mentally simulated actions in a virtual reality environment. Naive human subjects (n = 15) were instr ucted to imagine themselves walking in a three-dimensional virtual env ironment toward gates of different apparent widths placed at three dif ferent apparent distances. Each subject performed nine blocks of six t rials in a randomised order. The response time (reaction time and ment al walking time) was measured as the duration between an acoustic go s ignal and a motor signal produced by the subject. There was a combined effect on response time of both gate width and distance. Response tim e increased for decreasing apparent gate widths when the gate was plac ed at different distances. These results support the notion that menta lly simulated actions are governed by central motor rules.