Using The Method Of Constant Stimulus To Study Cue Choosing In Braking

The structure doctrine psychologists considered that we perceive an object after it represent. That is to say, when we perceive speed, acceleration, distance and other information, they must be operated in our brain first and then control our behavior. But some other researchers argues that we have an appropriate method to describe the environment, which is not necessarily be one based on abstractions such as "points" and "planes". Lee has demonstrated that time to contact (TTC) can be obtained from the image of an approaching object without obtaining either its distance or its velocity. More specifically, it is the ratio at any instant of the distance of any point from the centre of an expanding optical pattern to its velocity away from the center. Notice that this can be obtained without having to determine either the distance of the surface or its velocity and that it does not mater whether the velocity arises from motion of the surface, the perceiver, or both. Lee (1976) further showed that the time derivative of tau ("tau-dot") could be used to control deceleration during braking. Tau-dot can directly provide information about whether one's current level of deceleration is sufficient to stop in front of an object.In this study, we used the VR technology and the method of constant stimulus to study cue choosing in braking. A slowing down car was presented to subjects. When its speed was not 0, we masked the screen, and asked the subjects to judge the position when the car stopped.In experiment 1, we used the VR technology and the method of constant stimulus to present the stimulus, reducing the impact of human factors. The results showed that subjects could use distance cues and deceleration cues in braking behavior.In experiment 2, we tested why the point of subjective equality shifted in experiment 1. The male subject's result not shifted at all the point except the point of subjective equality in distance condition and deceleration condition, but the female subjects shifted at all the point. Those results suggested that, the male subject became more conservative, but for the female subjects, maybe their threshold changed.