Activations in visual and attention-related areas predict and correlate with the degree of perceptual learning
Activations in visual and attention-related areas predict and correlate with the degree of perceptual learning
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DOI：
10.1523/jneurosci.3002-07.2007
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发表时间：
2007-10-17
影响因子：
5.3
通讯作者：
Ungerleider, Leslie G.
中科院分区：
文献类型：
--
作者：
Mukai, Ikuko;Kim, David;Ungerleider, Leslie G.
视觉刺激的重复体验可以导致对刺激的感知改善，即。例如，知觉学习为了了解这一过程的潜在神经机制，我们使用功能性磁共振成像来跟踪对比辨别任务训练过程中的大脑激活。根据他们在一次扫描中提高任务的能力，受试者被分为两组：“学习者”和“非学习者”。随着学习的进展，学习者表现出视觉皮层的激活逐渐减少，包括布罗德曼的18和19区和梭状回，以及与注意力网络相关的几个皮层区域，即顶内沟（IPS），额眼场（FEF）和补充眼场。在学习者中，这些区域大脑激活的减少与成绩提高的幅度高度相关。与学习者不同，非学习者在训练过程中大脑激活没有变化。在训练的最初阶段，学习者在所有这些大脑区域都表现出比非学习者更强的激活，这表明人们可以从最初的激活水平预测谁会学习，谁不会。此外，在培训过程中，IPS和FEF之间的功能连接在右半球与早期视觉区的学习者比非学习者更强。我们推测，锐化调谐的神经元表示可能会导致减少激活视觉皮层知觉学习过程中，注意力可能会促进这一进程，通过相互作用的注意力相关的视觉皮层区域。
Repeated experience with a visual stimulus can result in improved perception of the stimulus, i. e., perceptual learning. To understand the underlying neural mechanisms of this process, we used functional magnetic resonance imaging to track brain activations during the course of training on a contrast discrimination task. Based on their ability to improve on the task within a single scan session, subjects were separated into two groups: "learners" and "nonlearners." As learning progressed, learners showed progressively reduced activation in both visual cortex, including Brodmann's areas 18 and 19 and the fusiform gyrus, and several cortical regions associated with the attentional network, namely, the intraparietal sulcus (IPS), frontal eye field (FEF), and supplementary eye field. Among learners, the decrease in brain activations in these regions was highly correlated with the magnitude of performance improvement. Unlike learners, nonlearners showed no changes in brain activations during training. Learners showed stronger activation than nonlearners during the initial period of training in all these brain regions, indicating that one could predict from the initial activation level who would learn and who would not. In addition, over the course of training, the functional connectivity between IPS and FEF in the right hemisphere with early visual areas was stronger for learners than nonlearners. We speculate that sharpened tuning of neuronal representations may cause reduced activation in visual cortex during perceptual learning and that attention may facilitate this process through an interaction of attention-related and visual cortical regions.