Dissociable effects of top-down and bottom-up attention during episodic encoding.
Dissociable effects of top-down and bottom-up attention during episodic encoding.
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DOI：
10.1523/jneurosci.0152-11.2011
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发表时间：
2011-08-31
期刊：
影响因子：
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通讯作者：
Wagner AD
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文献类型：
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作者：
Uncapher MR;Hutchinson JB;Wagner AD
生活经历的记忆形成情景记忆受到我们如何关注这些经历的影响，这是公认的，但注意力塑造情景编码的神经机制仍然不清楚。我们研究了自上而下和自下而上的注意力如何有助于人类视觉对象的记忆编码，通过操纵这两种类型的注意力在功能磁共振成像（fMRI）的情景记忆形成。我们发现，背顶叶皮层，特别是，顶内沟（IPS），从事自上而下的注意力，也招募成功的情景记忆的形成过程中。相比之下，自下而上的注意力集中在腹侧顶叶皮层，特别是颞顶交界处（TPJ），在编码失败时也更活跃。功能连接分析揭示了自上而下和自下而上的注意力如何影响编码的进一步分离：虽然IPS和TPJ都影响了被认为代表编码信息的感知皮层（梭状/外侧枕叶皮层）的活动，但它们各自对记忆编码产生相反的影响。具体而言，在刺激呈现之前的准备期间，IPS的更强驱动力与随后出席的刺激被编码的可能性更高相关。相比之下，在刺激处理过程中，与TPJ的较强连接性与刺激成功编码的可能性较低相关。这些研究结果表明，在编码的视觉对象到情节记忆，自上而下和自下而上的注意可以有相反的影响知觉领域，有助于视觉对象的表征，这表明，注意调节记忆的方式之一是通过改变知觉加工的编码刺激。
It is well established that the formation of memories for life’s experiences—episodic memory—is influenced by how we attend to those experiences, yet the neural mechanisms by which attention shapes episodic encoding are still unclear. We investigated how top-down and bottom-up attention contribute to memory encoding of visual objects in humans by manipulating both types of attention during functional magnetic resonance imaging (fMRI) of episodic memory formation. We show that dorsal parietal cortex—specifically, intraparietal sulcus (IPS)—was engaged during top-down attention and was also recruited during the successful formation of episodic memories. By contrast, bottom-up attention engaged ventral parietal cortex—specifically, temporoparietal junction (TPJ)—and was also more active during encoding failure. Functional connectivity analyses revealed further dissociations in how top-down and bottom-up attention influenced encoding: while both IPS and TPJ influenced activity in perceptual cortices thought to represent the information being encoded (fusiform/lateral occipital cortex), they each exerted opposite effects on memory encoding. Specifically, during a preparatory period preceding stimulus presentation, a stronger drive from IPS was associated with a higher likelihood that the subsequently attended stimulus would be encoded. By contrast, during stimulus processing, stronger connectivity with TPJ was associated with a lower likelihood the stimulus would be successfully encoded. These findings suggest that during encoding of visual objects into episodic memory, top-down and bottom-up attention can have opposite influences on perceptual areas that subserve visual object representation, suggesting that one manner in which attention modulates memory is by altering the perceptual processing of to-be-encoded stimuli.