In Witt, J. K., & Proffitt, D. R. (2005), the experiments assess whether the influence of effort on distance perception is generally or functionally specific. In the first three experiments, the effort for throwing was manipulated by having half of the participants throw a heavy ball and the other half throw a light ball. It was found that effort for throwing influenced verbal reports of distance as well as perceptual distance - matching tasks, but, effort for throwing did not influence blindwalking. In the fourth experiment, the effort for throwing was manipulated as well as intention for action. All participants threw a heavy ball and then made verbal estimates of distance. Afterwards, half of the participants blindwalked to the target while
