Crawford T J, Muller H J
Charing Cross and Westminster Medical School, Department of Clinical Neurosciences, Charing Cross Hospital, London, England.
Vision Res. 1992 Feb;32(2):293-304. doi: 10.1016/0042-6989(92)90140-e.
A spatial cueing paradigm was used to (a) investigate the effects of attentional orienting on spatial and temporal parameters of saccadic eye movements and (b) examine hypotheses regarding the hierarchical programming of saccade direction and amplitude. On a given trial, the subjects were presented with one of three peripheral cues: a "valid" cue provided correct information, a "neutral" cue no information and an "invalid" cue incorrect information about the location of the subsequent target (the cue was valid on about 50% of the trials). 100 or 500 msec after the cue onset (stimulus onset asynchrony, SOA), the eye movement target was presented at one of six possible locations (from -11.25 degrees to +11.25 degrees, at 3.75 degrees spacing). The results showed a significant effect of cueing on saccade latencies at the 100 msec, but no effect at the 500 msec SOA. The cueing benefits were restricted to the cued location; no other locations within the cued or uncued hemi-field were facilitated. The invalid trial latencies showed: (a) no advantage for targets on the same side as the cue relative to the opposite side, (b) no advantage for targets more proximal to the cue and (c) no advantage for targets sharing the same eccentricity as the cue. In a second experiment, subjects responded to the target by giving a simple manual response [simple reaction time (RT)] while keeping the eyes stationary. The results showed a significant cueing effect on simple RTs both at the 100 msec and, in contrast to saccadic eye movements, the 500 msec SOA. There were specific benefits for targets at the cued location relative to other targets within the same and opposite hemi-fields. Further, in contrast to saccades, there was a general advantage for targets within the same ("cued") hemi-field over targets in the opposite hemi-field. These findings suggest that, for saccadic eye movements (overt orienting), direction and amplitude are programmed holistically; whereas in covert orienting (with eyes stationary), motor parameters (e.g. for directed hand movements) are programmed in a more hierarchical fashion.
(a) 研究注意定向对眼跳运动的空间和时间参数的影响，以及 (b) 检验关于眼跳方向和幅度的分层编程的假设。在给定的试验中，向受试者呈现三种外周线索之一：“有效”线索提供正确信息，“中性”线索不提供信息，“无效”线索提供关于后续目标位置的错误信息（该线索在约50%的试验中有效）。线索开始后100或500毫秒（刺激开始异步，SOA），眼动目标呈现在六个可能位置之一（从 -11.25度到 +11.25度，间隔3.75度）。结果显示，在100毫秒时线索对眼跳潜伏期有显著影响，但在500毫秒SOA时没有影响。线索提示的益处仅限于线索提示的位置；线索提示或未提示的半视野内的其他位置均未得到促进。无效试验潜伏期显示：(a) 相对于对侧，线索同侧的目标没有优势，(b) 更靠近线索的目标没有优势，以及 (c) 与线索具有相同偏心率的目标没有优势。在第二个实验中，受试者通过做出简单的手动反应 [简单反应时 (RT)] 对目标做出反应，同时保持眼睛静止。结果显示，在100毫秒时以及与眼跳运动不同的是，在500毫秒SOA时，线索对简单反应时有显著影响。相对于同一和对侧半视野内的其他目标，线索提示位置的目标有特定益处。此外，与眼跳不同的是，同一（“线索提示”）半视野内的目标相对于对侧半视野内的目标有总体优势。这些发现表明，对于眼跳运动（明显的定向），方向和幅度是整体编程的；而在隐蔽定向（眼睛静止）中，运动参数（例如用于定向手部运动的参数）是以更分层的方式编程的。
