反向眼跳的实验范式、机制及影响因素

反向眼跳任务是研究内源性眼跳的主要方法。1978年，Hallett在研究中首次使用了反向眼跳的实验任务。实验中要求被试抑制对外围目标的注视，并注视它的相反位置。反向眼跳任务是研究行为控制以及注意功能的有效范式。目前认为反向眼跳任务中的朝向眼跳和反向眼跳计划是同时加工并相互竞争的，并且反向眼跳的产生与额顶叶皮层下组织有关。反向眼跳会受到多种因素的影响，例如，空白效应、工作记忆、认知老化、目标离心率等。

Antisaccades and Its Experimental Paradigm,Mechanisms and Influencing Factors

The antisaccades task is the main method to study endogenous saccades. In 1978 Hallett used the task in his study for the first time. The task was developed from the standard prosaccade task. In the task the participants fixated a central stimulus replaced by a sudden onset target that appeared at some distance to the left or right. The participants were told to refrain from looking at the peripheral target and direct their gaze instead in the opposite direction. The subjects were to inhibit the saccade towards the peripheral target, and direct their gaze in the opposite direction. There were three paradigms: the gap paradigm, the overlap paradigm, and the null paradigm. This task could provide many metrics, such as saccade latency, error rate, and time to correct error saccade. In order to find the different effects of endogenous and exogenous factors on the saccades, many studies contrasted antisaccades with prosaccades. Compared with prosaccades, antisaccades tended to have higher response latencies and error rates, but saccade errors could be corrected very quickly, much faster than the latency of prosaccade. To perform a correct antisaccade, the participants were to inhibit a reflexive prosaccade to the sudden onset target and initiate an alternative antisaccade to the opposite direction, and the plan of prosaccades and antisaccades could be programmed in parallel and be competitive. If the antisaccades system reached the threshold fast enough, the correct antisaccade was initiated and the reflexive prosaccade was canceled. But, if the endogenous processes failed to inhibit the activation of the prosaccades system and canceled the prosaccades program, an erroneous prosaccade toward the target was made, and the correct antisaccade followed. Evidence suggests that antisaccades can be influenced by many factors. Firstly, the "gap effect" is an important phenomenon in the antisaccades task. If there is a short gap before the target appears, the saccades tend to be faster than otherwise. These speeded saccades are thought to indicate that a tendency to keep the eye on the currently fixated stimulus. Secondly, the distance between the central fixation and peripheral target can affect the latency and error rate of antisaccades. This effect has something to do with the structure of retina. Thirdly, many studies suggest that working memory has something to do with the generation of antisaccades. Working memory plays an important role in inhibiting reflexive response, and helps to inhibit the prosaccades and initiate the antisaccades. Fourthly, the ability to perform antisaccades is not constant across the lifespan, and broadly consistent with the development of the prefrontal cortex. The decline in the antisaccade of old participants might be directly due to the decrease of working memory capacity induced by cognitive aging. The antisaccades task provides an efficient method for the study of behavioral control and attention, but still a lot of questions need to be discussed.