State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China.
J Neurosci. 2010 Jul 21;30(29):9869-76. doi: 10.1523/JNEUROSCI.0140-10.2010.
In high-level perceptual regions of the ventral visual pathway in humans, experience shapes the functional properties of the cortex: the fusiform face area responds most strongly to faces of familiar rather than unfamiliar races, and the visual word form area (VWFA) is tuned only to familiar orthographies. But are these regions affected only by the bottom-up stimulus information they receive during learning, or does the effect of perceptual experience depend on the way that stimulus information is used during learning? Here, we test the hypothesis that top-down influences (i.e., task context) modulate the effect of perceptual experience on functional selectivities of the high-level visual cortex. Specifically, we test whether experience with novel visual stimuli produces a greater effect on the VWFA when those stimuli are associated with meanings (via association learning) but produces a greater effect on shape-processing regions when trained in a discrimination task without associated meanings. Our result supports this hypothesis and further shows that learning is transferred to novel objects that share parts with the trained objects. Thus, the effects of experience on selectivities of the high-level visual cortex depend on the task context in which that experience occurs and the perceptual processing strategy by which objects are encoded during learning.
在人类腹侧视觉通路的高级感知区域，经验塑造了大脑皮层的功能特性：梭状回面孔区对面孔的反应最强烈，而熟悉的种族面孔比不熟悉的种族面孔更强烈，而视觉词形区（VWFA）只对熟悉的正字法敏感。但是，这些区域仅受学习过程中接收到的自下而上的刺激信息影响，还是感知经验的影响取决于学习过程中刺激信息的使用方式？在这里，我们检验了一个假设，即自上而下的影响（即任务上下文）调节感知经验对高级视觉皮层功能选择性的影响。具体来说，我们测试了当这些刺激与意义相关联（通过联想学习）时，新颖的视觉刺激对 VWFA 产生更大的影响，而当在没有相关意义的辨别任务中进行训练时，新颖的视觉刺激对形状处理区域产生更大的影响。我们的结果支持了这一假设，并进一步表明，学习会转移到与训练对象具有部分相同部分的新对象上。因此，经验对高级视觉皮层选择性的影响取决于经验发生的任务上下文以及学习过程中对象编码的感知处理策略。
