Differential Contributions of GABA Concentration in Frontal and Parietal Regions to Individual Differences in Attentional Blink
Differential Contributions of GABA Concentration in Frontal and Parietal Regions to Individual Differences in Attentional Blink
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DOI：
10.1523/jneurosci.0764-16.2016
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发表时间：
2016-08-24
影响因子：
5.3
通讯作者：
Kawahara, Jun I.
中科院分区：
文献类型：
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作者：
Kihara, Ken;Kondo, Hirohito M.;Kawahara, Jun I.
在复杂的视觉场景中，选择性注意在识别瞬变物体方面起着重要的作用。注意控制能力因观察者而异。然而，目前还不清楚是什么神经机制导致了注意控制能力的个体差异。本研究采用以下注意瞬变范式：当在快速连续视觉呈现中识别两个目标时，第一个目标的处理会中断第一个目标出现后500 ms内出现的第二个目标的识别。第二目标准确性的降低主要是由于GABA系统调节了从第一目标到第二目标的注意力重定向的短暂抑制。利用磁共振波谱技术，研究了人类注意瞬变幅度的个体差异是否与左前额叶皮层（PFC）、右后顶叶皮层（PPC）和视觉皮层（VC）的GABA浓度相关。前皮层GABA浓度与注意眨眼量呈负相关，与第一目标正确率呈正相关。PPC GABA浓度与注意瞬变幅度呈正相关。然而，在VC中GABA浓度对注意眨眼幅度和第一目标准确性没有影响。我们的研究结果表明，额顶叶抑制机制与注意加工的个体差异密切相关，并且gaba能系统在PFC和PPC中选择性注意中的功能作用不同。
Selective attention plays an important role in identifying transient objects in a complex visual scene. Attentional control ability varies with observers. However, it is unclear what neural mechanisms are responsible for individual differences in attentional control ability. The present study used the following attentional blink paradigm: when two targets are to be identified in rapid serial visual presentation, the processing of the first target interrupts the identification of the second one appearing within 500 ms after the first-target onset. It has been assumed that the reduction of the second-target accuracy is mainly due to a transient inhibition of attentional reorienting from the first to the second target, which is modulated by the GABA system. Using magnetic resonance spectroscopy, we investigated whether individual variation of attentional blink magnitude is associated with GABA concentrations in the left prefrontal cortex (PFC), right posterior-parietal cortex (PPC), and visual cortex (VC) of humans. GABA concentrations in the PFC were related negatively to attentional blink magnitude and positively to the first-target accuracy. GABA concentrations in the PPC were positively correlated with attentional blink magnitude. However, GABA concentrations in the VC did not contribute to attentional blink magnitude and first-target accuracy. Our results suggest that frontoparietal inhibitory mechanisms are closely linked with individual differences in attentional processing and that functional roles of the GABAergic system in selective attention differ between the PFC and PPC.