Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, United Kingdom.
Proc Natl Acad Sci U S A. 2012 Feb 7;109(6):E360-7. doi: 10.1073/pnas.1108555108. Epub 2011 Nov 22.
Past experience provides a rich source of predictive information about the world that could be used to guide and optimize ongoing perception. However, the neural mechanisms that integrate information coded in long-term memory (LTM) with ongoing perceptual processing remain unknown. Here, we explore how the contents of LTM optimize perception by modulating anticipatory brain states. By using a paradigm that integrates LTM and attentional orienting, we first demonstrate that the contents of LTM sharpen perceptual sensitivity for targets presented at memory-predicted spatial locations. Next, we examine oscillations in EEG to show that memory-guided attention is associated with spatially specific desynchronization of alpha-band activity over visual cortex. Additionally, we use functional MRI to confirm that target-predictive spatial information stored in LTM triggers spatiotopic modulation of preparatory activity in extrastriate visual cortex. Finally, functional MRI results also implicate an integrated cortical network, including the hippocampus and a dorsal frontoparietal circuit, as a likely candidate for organizing preparatory states in visual cortex according to the contents of LTM.
过去的经验为世界提供了丰富的预测信息来源，这些信息可以用来指导和优化正在进行的感知。然而，将长期记忆（LTM）中编码的信息与正在进行的感知处理整合的神经机制尚不清楚。在这里，我们通过调节预期的大脑状态来探索 LTM 内容如何优化感知。通过使用一种整合 LTM 和注意力定向的范式，我们首先证明 LTM 的内容可以提高在记忆预测的空间位置呈现的目标的感知敏感性。接下来，我们检查 EEG 中的振荡，以表明记忆引导的注意力与视觉皮层上的 alpha 波段活动的空间特异性去同步有关。此外，我们使用功能磁共振成像（fMRI）来证实 LTM 中存储的与目标预测相关的空间信息会触发预备活动在视觉皮层中的空间调制。最后，功能磁共振成像（fMRI）结果还表明，一个包括海马体和背侧额顶叶回路在内的综合皮层网络可能是根据 LTM 的内容组织视觉皮层预备状态的候选者。
