Judgment and action knowledge in speed adjustment tasks: experiments in a virtual environment.

Two experiments were conducted to investigate children’s and adults’ knowledge of time and speed in action and judgment tasks. Participants had to set the speed of a moving car to a new speed so that it would reach a target line at the same time as a reference car moving at a higher speed and disappearing in a tunnel at the midway point. In Experiment 1 (24 10–year–olds, 24 adults), children’s and adults’ speed adjustments followed the normative pattern when responses had to be graded linearly as a function of the car’s initial speed. In a non–linear condition, only adults’ action responses corresponded with the normative function. Simplifying the task by shortening the tunnel systematically in Experiment 2 (24 10–year–olds, 24 adults) enabled children to grade the speeds adequately in the action conditions only. Adults now produced normative response patterns in both judgment and action. Whether people show linearization biases was thus shown to depend on the interaction of age, task demands and response mode. [ABSTRACT FROM AUTHOR]