Top-down enhancement and suppression of the magnitude and speed of neural activity
Top-down enhancement and suppression of the magnitude and speed of neural activity
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DOI：
10.1162/0898929053279522
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发表时间：
2005-03-01
影响因子：
3.2
通讯作者：
D'Esposito, M
中科院分区：
文献类型：
--
作者：
Gazzaley, A;Cooney, JW;D'Esposito, M
自上而下的调节是我们选择性地关注相关刺激和忽略不相关刺激的能力的基础。解决顶小丑调制的神经机制的理论是由研究驱动的，这些研究揭示了响应于定向注意的神经活动的增加幅度，但是由于缺乏神经处理速度的数据报告调制以及与评估增强和抑制存在所需的感知（被动视图）基线的比较而受到限制。利用功能性磁共振成像（fMRI）和事件相关电位记录（FRP），我们提供了收敛的证据表明，神经活动的大小和神经处理的速度都受到了小丑的影响。此外，增强和抑制都相对于感知基线发生，这取决于任务指令。这些发现揭示了目标导向注意对视觉关联皮层活动的影响程度。我们进一步证明了自上而下的增强与工作记忆性能缺陷相对应的容量限制。
Top-down modulation underlies our ability to selectively attend to relevant stimuli and to ignore irrelevant stimuli. Theories addressing neural mechanisms of top-clown modulation are driven by studies that reveal increased magnitude of neural activity in response to directed attention, but are limited by a lack of data reporting modulation Of neural processing speed, as well as comparisons with a perceptual (passive view) baseline necessary to evaluate the presence of enhancement and suppression. Utilizing functional MRI (fMRI) and event-related potential recordings (FRPs), we provide converging evidence that both the magnitude of neural activity and the speed of neural processing are modulated by top-clown influences. Furthermore, both enhancement and suppression Occur relative to a perceptual baseline depending on task instruction. These findings reveal the fine degree of influence that goal-directed attention exerts upon activity within the visual association cortex. We further document capacity limitations in top-down enhancement corresponding with working memory performance deficits.