THE TIME COURSE OF MEMORY FORWARD AND DOWNWARD DISPLACEMENTS OF CONTINUOUS MOVING TARGETS
When people are instructed to locate the vanishing position of a horizontally moving target, both forward (in the direction of motion â€“ M-Displacement) and downward (in the direction of gravity â€“ O-Displacement) errors of localization typically occur. Though several determinants of those errors have been ascertained, little is known regarding their time course. The present study attempts to fill this gap. Horizontally moving targets with varying velocities were presented and participants instructed to locate their vanishing position, either via a mouse or a pointer (on a touch screen), after a variable imposed time delay. Outcomes revealed an overall inverted-L shape of the errors trajectory as a function of time delay in the mouse, but not in the pointer condition. These findings are discussed with a link to the â€œstraight-down beliefâ€ and what has come to be known as the â€œroad-runner physicsâ€.