Kowler E
Department of Psychology, Rutgers University, New Brunswick, NJ 08903.
Vision Res. 1989;29(9):1049-57. doi: 10.1016/0042-6989(89)90052-7.
Human smooth pursuit eye movements anticipate the future path of moving targets. Anticipatory pursuit is sometimes attributed to cognitive expectations about future motion and other times to the habitual repetition of previous pursuit responses. Expectations and habits were separated by having subjects smoothly pursue a target moving along a randomly-selected path that was either undisclosed to the subject before each trial or disclosed by means of auditory or visual cues. When the path was undisclosed, the direction of anticipatory smooth eye movements was determined by the direction of target motion in the previous trial. In the presence of cues-the critical condition for separating habits and expectations-effects of previous trials diminished and anticipatory smooth eye movements were primarily determined by the direction of motion the subject was told to expect. These results show a strong contribution of cognitive expectations which overrides persevering smooth oculomotor habits. Smooth pursuit eye movements are driven by a signal that combines the present target motion with the target motion expected to occur several hundred milliseconds into the future. The expected motion is based on a genuine cognitive prediction, not lower-level sensory or motor memories of past events.
人类的平稳跟踪眼球运动能预测移动目标的未来轨迹。预期性跟踪有时被归因于对未来运动的认知预期，有时则被归因于先前跟踪反应的习惯性重复。通过让受试者平稳跟踪沿随机选择路径移动的目标，将预期和习惯区分开来，该路径在每次试验前要么不向受试者透露，要么通过听觉或视觉线索透露。当路径未被透露时，预期性平稳眼球运动的方向由前一次试验中目标运动的方向决定。在有线索的情况下——区分习惯和预期的关键条件——前一次试验的影响减弱，预期性平稳眼球运动主要由受试者被告知预期的运动方向决定。这些结果表明认知预期的强大作用，它压倒了持续的平稳动眼习惯。平稳跟踪眼球运动由一个信号驱动，该信号将当前目标运动与预计在未来几百毫秒内发生的目标运动结合起来。预期运动基于真正的认知预测，而不是过去事件的低级感觉或运动记忆。
