Time-varying cortical activations related to visual-tactile cross-modal links in spatial selective attention
Time-varying cortical activations related to visual-tactile cross-modal links in spatial selective attention
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DOI：
10.1152/jn.00007.2007
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发表时间：
2007-05-01
影响因子：
2.5
通讯作者：
Kakigi, Ryusuke
中科院分区：
文献类型：
--
作者：
Kida, Tetsuo;Inui, Koji;Kakigi, Ryusuke
单峰空间注意背后的神经机制一直被研究，但跨通道联系背后的皮质过程仍然是一个有争议的问题。为了揭示空间注意中视觉和触觉之间跨模式联系背后的皮质过程，我们记录了当受试者将注意力引向随机出现在左侧或右侧空间的电刺激或视觉刺激时，对皮肤电刺激的脑磁图(MEG)反应。在电刺激后85ms和100ms时，在双侧侧裂周围记录的神经反应在触摸无关和相关模式下都被空间注意显著增强。来源分析表明，西尔维安反应产生于次级躯体感觉皮质(SII)。在对侧初级躯体感觉皮层(SI)产生的早期反应M50c不受注意的调节。注意来源的位置或磁场分布没有明显的变化，提示注意促进了SII本身的神经活动，而不是紧张性偏向效应或独立神经元群体的重叠。结果表明，在SII中，空间注意增强了对触觉输入的反应，这种反应不依赖于被注意的感觉通道。潜在的机制仍有待确定，但可能是收益增加。
The neural mechanisms underlying unimodal spatial attention have long been studied, but the cortical processes underlying cross-modal links remain a matter of debate. To reveal the cortical processes underlying the cross-modal links between vision and touch in spatial attention, we recorded magnetoencephalographic (MEG) responses to electrocutaneous stimuli when subjects directed attention to an electrocutaneous or visual stimulus presented randomly in the left or right space. Neural responses recorded around the bilateral sylvian fissures at 85 and 100 ms after the electrocutaneous stimulus were significantly enhanced by spatial attention in both the touch-irrelevant and-relevant modalities. Source analysis revealed that the sylvian responses were generated in the secondary somatosensory cortex (SII). An early response, M50c, generated in the contralateral primary somatosensory cortex (SI), was not modulated by attention. There were no significant attentional changes in the source location or magnetic field distribution, suggesting attentional facilitation of the neural activity in SII itself, rather than a tonic bias effect or overlapping of separate neuronal populations. The results show that spatial attention enhances responses to tactile inputs in SII, independent of sensory modality attended. The underlying mechanism remains to be determined, but may be an increase in gain.