Vaina Lucia M, Chubb Charles
Brain and Vision Research Laboratory, Departments of Biomedical Engineering, Neuroscience and Neurology, Boston University, Boston, MA 02215, USA.
Atten Percept Psychophys. 2012 Jul;74(5):1009-19. doi: 10.3758/s13414-012-0290-3.
Previous studies investigating transfer of perceptual learning between luminance-defined (LD) motion and texture-contrast-defined (CD) motion tasks have found little or no transfer from LD to CD motion tasks but nearly perfect transfer from CD to LD motion tasks. Here, we introduce a paradigm that yields a clean double dissociation: LD training yields no transfer to the CD task, but more interestingly, CD training yields no transfer to the LD task. Participants were trained in two variants of a global motion task. In one (LD) variant, motion was defined by tokens that differed from the background in mean luminance. In the other (CD) variant, motion was defined by tokens that had mean luminance equal to the background but differed from the background in texture contrast. The task was to judge whether the signal tokens were moving to the right or to the left. Task difficulty was varied by manipulating the proportion of tokens that moved coherently across the four frames of the stimulus display. Performance in each of the LD and CD variants of the task was measured as training proceeded. In each task, training produced substantial improvement in performance in the trained task; however, in neither case did this improvement show any significant transfer to the nontrained task.
以往关于探究亮度定义（LD）运动和纹理对比度定义（CD）运动任务之间知觉学习迁移的研究发现，从LD运动任务到CD运动任务几乎没有或完全没有迁移，但从CD运动任务到LD运动任务却有近乎完美的迁移。在此，我们引入了一种能产生清晰双重解离的范式：LD训练对CD任务没有迁移效应，但更有趣的是，CD训练对LD任务也没有迁移效应。参与者接受了全局运动任务的两种变体训练。在一种（LD）变体中，运动由平均亮度与背景不同的标记定义。在另一种（CD）变体中，运动由平均亮度与背景相同但纹理对比度与背景不同的标记定义。任务是判断信号标记是向右还是向左移动。通过操纵在刺激显示的四个帧中连贯移动的标记比例来改变任务难度。在训练过程中测量任务的每个LD和CD变体中的表现。在每个任务中，训练都使训练任务的表现有了显著提高；然而，在这两种情况下，这种提高都没有显示出对未训练任务有任何显著的迁移。
