Department of Psychology, University of California-Riverside, Riverside, California 92521.
Department of Psychology, University of California-Riverside, Riverside, California 92521
J Neurosci. 2014 Jun 18;34(25):8423-31. doi: 10.1523/JNEUROSCI.0745-14.2014.
Human perceptual learning is classically thought to be highly specific to trained stimuli's retinal location. Together with evidence that specific learning effects can result in corresponding changes in early visual cortex, researchers have theorized that specificity implies regionalization of learning in the brain. However, other research suggests that specificity can arise from learning readout in decision areas or through top-down processes. Notably, recent research using a novel double-training paradigm reveals dramatic generalization of perceptual learning to untrained locations when multiple stimuli are trained. These data provoked significant controversy in the field and challenged extant models of perceptual learning. To resolve this controversy, we investigated mechanisms that account for retinotopic specificity in perceptual learning. We replicated findings of transfer after double training; however, we show that prolonged training at threshold, which leads to a greater number of difficult trials during training, preserves location specificity when double training occurred at the same location or sequentially at different locations. Likewise, we find that prolonged training at threshold determines the degree of transfer in single training of a peripheral orientation discrimination task. Together, these data show that retinotopic specificity depends highly upon particularities of the training procedure. We suggest that perceptual learning can arise from decision rules, attention learning, or representational changes, and small differences in the training approach can emphasize some of these over the others.
人类感知学习被认为高度特定于训练刺激的视网膜位置。结合特定学习效果会导致早期视觉皮层相应变化的证据，研究人员推测，特异性意味着大脑学习的区域化。然而，其他研究表明，特异性可以源自决策区域的学习读出，或者通过自上而下的过程。值得注意的是，最近使用新颖的双重训练范式的研究表明，当训练多个刺激时，感知学习会显著泛化到未训练的位置。这些数据在该领域引起了重大争议，并挑战了现有的感知学习模型。为了解决这一争议，我们研究了解释感知学习中视网膜特异性的机制。我们复制了双重训练后的转移发现；然而，我们表明，在相同位置或不同位置顺序进行双重训练时，在阈值处进行长时间训练会导致更多困难试验，从而保留位置特异性。同样，我们发现，在阈值处进行长时间训练决定了在单次外周方向辨别任务训练中的转移程度。总之，这些数据表明，视网膜特异性高度依赖于训练程序的特殊性。我们认为，感知学习可以源自决策规则、注意力学习或表示变化，并且训练方法的细微差异可以强调其中一些而不是其他。
