Tsushima Yoshiaki, Seitz Aaron R, Watanabe Takeo
Curr Biol. 2008 Jun 24;18(12):R516-7. doi: 10.1016/j.cub.2008.04.029.
The role of attention in perceptual learning has been controversial. Numerous studies have reported that learning does not occur on stimulus features that are irrelevant to a subject's task [1,2] and have concluded that focused attention on a feature is necessary for a feature to be learned. In contrast, another line of studies has shown that perceptual learning occurs even on task-irrelevant features that are subthreshold, and concluded that attention on a feature is not required to learn that feature [3-5]. Here we attempt to reconcile these divergent findings by systematically exploring the relation between signal strength of the motion stimuli used during training and the resultant magnitude of perceptual learning. Our results show that performance improvements only occurred for the motion-stimuli trained at low, parathreshold, coherence levels. The results are in accord with the hypothesis that weak task-irrelevant signals fail to be 'noticed', and consequently to be suppressed, by the attention system and thus are learned, while stronger stimulus signals are detected, and suppressed [6], and are not learned. These results provide a parsimonious explanation of why task-irrelevant learning is found in some studies but not others, and could give an important clue to resolving a long-standing controversy.
注意力在知觉学习中的作用一直存在争议。众多研究报告称，学习不会发生在与主体任务无关的刺激特征上[1,2]，并得出结论，对某一特征的集中注意力是该特征得以学习的必要条件。相比之下，另一系列研究表明，即使在低于阈值的与任务无关的特征上也会发生知觉学习，并得出结论，学习某一特征并不需要对该特征加以注意[3-5]。在此，我们试图通过系统地探究训练期间所使用的运动刺激的信号强度与知觉学习的最终程度之间的关系，来调和这些不同的研究结果。我们的研究结果表明，只有在低相干水平（接近阈值）下训练的运动刺激才会出现性能提升。这些结果符合以下假设：微弱的与任务无关的信号无法被注意力系统“注意”到，因此不会被抑制，从而得以被学习，而较强的刺激信号则会被检测到并被抑制[6]，因而无法被学习。这些结果为为何在某些研究中能发现与任务无关的学习而在其他研究中却未发现提供了一个简洁的解释，并可能为解决一个长期存在的争议提供重要线索。
