Effects of a target movement direction cue on head-tracking performance

A review of the literature has shown that most investigations of head-track ing performance have used symmetrically shaped targets. This paper identifi es a problem in using circular targets to represent the movement of complex targets (i.e. targets giving directional cues). Two experiments investigat ed the effects of a target direction cue on head-tracking performance. In t he first experiment. practice did nor improve performance when tracking eit her with or without a 'look-ahead trace' showing all target positions 160 m s into the future. A second experiment utilized a 'look-ahead trace' showin g target positions with eight different lead-times (0-560 ms). With lead-ti mes of 160 ms or more, significant improvements in tracking performance and subjective difficulty rating were obtained. Tracking responses were also s ignificantly affected. The results suggest caution when performance data ob tained with a symmetrical target are generalized to predict tracking perfor mance with a real target giving cues to the direction of movement. The look -ahead trace offers a systematic means of bridging the gap between a symmet rical target and a real target having direction of movement cues.