Ten Brink A F, Nijboer T C W, Van der Stoep N, Van der Stigchel S
Department of Experimental Psychology, Helmholtz Institute, Utrecht University, Heidelberglaan 2, 3584 CS, Utrecht, The Netherlands,
Exp Brain Res. 2014 Apr;232(4):1357-66. doi: 10.1007/s00221-014-3854-8. Epub 2014 Feb 11.
Eye movements towards a new target can be guided or disrupted by input from multiple modalities. The degree of oculomotor competition evoked by a distractor depends on both distractor and target properties, such as distractor salience or certainty regarding the target location. The ability to localize the target is particularly important when studying saccades made towards auditory targets, since determination of elevation and azimuth of a sound are based on different processes, and these processes may be affected independently by a distractor. We investigated the effects of a visual distractor on saccadic eye movements made to an auditory target in a two-dimensional plane. Results showed that the competition evoked by a vertical visual distractor was stronger compared with a horizontal visual distractor. The eye movements that were not captured by the vertical visual distractor were still influenced by it: a deviation of endpoints was seen in the direction of the visual distractor. Furthermore, the interference evoked by a high-contrast visual distractor was stronger compared with low-contrast visual stimuli, which was reflected by a faster initiation of an eye movement towards the high-contrast visual distractor and a stronger shift of endpoints in the direction of the high-contrast visual distractor. Together, these findings show that the influence of a visual distractor on aurally guided eye movements depends strongly on its location relative to the target, and to a lesser extent, on stimulus contrast.
朝向新目标的眼球运动可由多种感觉模态的输入引导或干扰。干扰物引发的眼球运动竞争程度取决于干扰物和目标的属性，如干扰物的显著性或目标位置的确定性。在研究朝向听觉目标的扫视时，定位目标的能力尤为重要，因为声音仰角和方位角的确定基于不同的过程，而这些过程可能会受到干扰物的独立影响。我们在二维平面中研究了视觉干扰物对朝向听觉目标的扫视眼动的影响。结果表明，垂直视觉干扰物引发的竞争比水平视觉干扰物更强。未被垂直视觉干扰物捕捉到的眼球运动仍受到其影响：在视觉干扰物的方向上可观察到终点的偏差。此外，高对比度视觉干扰物引发的干扰比低对比度视觉刺激更强，这表现为朝向高对比度视觉干扰物的眼球运动启动更快，以及终点在高对比度视觉干扰物方向上的偏移更强。总之，这些发现表明，视觉干扰物对听觉引导的眼球运动的影响很大程度上取决于其相对于目标的位置，在较小程度上取决于刺激对比度。
