Kristjánsson A, Chen Y, Nakayama K
Vision Sciences Laboratory, Harvard University, 33 Kirkland Street, Cambridge, Massachusetts 02138, USA.
Nat Neurosci. 2001 Oct;4(10):1037-42. doi: 10.1038/nn723.
To make a saccadic eye movement to a target we must first attend to it. It is therefore not surprising that diverting attention increases saccade latency, but is latency increased in all cases? We show that attending to a peripheral discrimination task has a paradoxical effect. If the stimulus to be attended appears shortly (100 to 300 ms) before an eye movement is made in a direction opposite to that of a presented stimulus (an antisaccade), its latency is reduced to well below baseline performance. In contrast, latencies for saccades toward the stimulus (prosaccades) are increased under similar conditions. This paradoxical effect may arise from competition between the processes mediating prosaccades and antisaccades. When the discrimination task is presented at the critical moment, it interferes with a reflexive prosaccade, allowing faster antisaccades. The results suggest that the suppression of sensorimotor reflexes can facilitate volitional motor acts.
要使眼睛向目标进行扫视运动，我们必须首先注意到该目标。因此，转移注意力会增加扫视潜伏期也就不足为奇了，但潜伏期在所有情况下都会增加吗？我们发现，关注一项外周辨别任务会产生一种矛盾的效果。如果在眼睛朝着与呈现刺激相反的方向（反扫视）运动之前不久（100至300毫秒）出现要关注的刺激，其潜伏期会降至远低于基线表现。相比之下，在类似条件下，朝着刺激的扫视（顺扫视）潜伏期会增加。这种矛盾的效果可能源于介导顺扫视和反扫视的过程之间的竞争。当辨别任务在关键时刻呈现时，它会干扰反射性顺扫视，从而使反扫视更快。结果表明，感觉运动反射的抑制可以促进意志性运动行为。
