Department of Psychology, Boston University, Boston, Massachusetts, United States of America.
PLoS One. 2012;7(4):e35946. doi: 10.1371/journal.pone.0035946. Epub 2012 Apr 26.
Attention plays a fundamental role in visual learning and memory. One highly established principle of visual attention is that the harder a central task is, the more attentional resources are used to perform the task and the smaller amount of attention is allocated to peripheral processing because of limited attention capacity. Here we show that this principle holds true in a dual-task setting but not in a paradigm of task-irrelevant perceptual learning. In Experiment 1, eight participants were asked to identify either bright or dim number targets at the screen center and to remember concurrently presented scene backgrounds. Their recognition performances for scenes paired with dim/hard targets were worse than those for scenes paired with bright/easy targets. In Experiment 2, eight participants were asked to identify either bright or dim letter targets at the screen center while a task-irrelevant coherent motion was concurrently presented in the background. After five days of training on letter identification, participants improved their motion sensitivity to the direction paired with hard/dim targets improved but not to the direction paired with easy/bright targets. Taken together, these results suggest that task-irrelevant stimuli are not subject to the attentional control mechanisms that task-relevant stimuli abide.
注意在视觉学习和记忆中起着基本的作用。一个高度确立的视觉注意原则是，中央任务越难，用于执行任务的注意力资源就越多，而由于注意力容量有限，分配给周边处理的注意力就越少。在这里，我们表明，这一原则在双重任务设置中成立，但在与任务无关的知觉学习范式中不成立。在实验 1 中，要求八名参与者在屏幕中央识别明亮或暗淡的数字目标，并同时记住呈现的场景背景。他们对与暗淡/困难目标配对的场景的识别表现比与明亮/容易目标配对的场景差。在实验 2 中，要求八名参与者在屏幕中央识别明亮或暗淡的字母目标，同时在背景中呈现与任务无关的连贯运动。在五天的字母识别训练后，参与者提高了对与困难/暗淡目标配对的方向的运动敏感性，但对与容易/明亮目标配对的方向的运动敏感性没有提高。总之，这些结果表明，与任务无关的刺激不受任务相关刺激遵守的注意力控制机制的影响。
