Perception-action coupling in an interceptive task: First-order time-to-contact as an input variable

The aim of this study was to test the required velocity model [Peper, C. E. , Bootsma, R. J., Mestre, D. R., & Bakker, F. C. ( 1994). Journal of Experi mental Psychology. Human Perception and Performance, 20, 591-612; Bootsma, R. J., Fayt, V., Zaal, F. T. J. M., & Laurent, M. (1997). Journal of Experi mental Psychology: Human Perception and Performance, 23, 1282-1289] by mani pulating one of its variables: the first-order time-to-contact. Participant s had to manually move a cart along a rectilinear track so that its arrival at a target point would coincide with the arrival of a moving object. The object's motion was simulated by the lighting up of diodes. The distance tr avelled by the moving object (2 and 4 m) and the approach duration (1, 1.25 , and 1.6 s) were experimentally controlled. Participants showed kinematic adaptation of their movements when the first-order time-to-contact varied, whereas changes in the distance travelled (or in the travel speed) had no i mpact on movement kinematics. Although the effect of first-order time-to-co ntact on the response latency was consistent with the model. its effect on movement kinematics was not. By an adapted version of the model, calibratin g the required velocity threshold to the moving target's presentation, 55% of the variance of the kinematic data could be explained. (C) 2000 Elsevier Science B.V. All rights reserved. PsycINFO classification: 2300; 2323.