Oscillatory sensory selection mechanisms during intersensory attention to rhythmic auditory and visual inputs: a human electrocorticographic investigation.
Oscillatory sensory selection mechanisms during intersensory attention to rhythmic auditory and visual inputs: a human electrocorticographic investigation.
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DOI：
10.1523/jneurosci.2164-11.2011
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发表时间：
2011-12-14
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影响因子：
--
通讯作者：
Foxe JJ
中科院分区：
文献类型：
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作者：
Gomez-Ramirez M;Kelly SP;Molholm S;Sehatpour P;Schwartz TH;Foxe JJ
振荡夹带机制在注意处理有节奏地发生的刺激时被调用，由此它们的相位对齐调节编码预期输入的神经元的兴奋性状态。这些机制已在δ带（1-3 Hz）中进行了检查，其中夹带频率与刺激速率相匹配。在这里，我们研究了亚δ节律刺激的夹带，即在感觉间视听任务期间从人类听觉皮质上的颅内电极记录。视听刺激以0.67 Hz呈现，而参与者在一个感觉流中检测到目标，而忽略另一个。发现夹带以两倍于刺激速率（1.33Hz）操作，并且这通过FFT谱中的较高振幅值、α振幅的循环调制以及δ相位与α功率之间的相位-振幅耦合来反映。此外，我们还发现，在视觉注意过程中，听觉皮层的α-振幅相对增加，与被忽略的听觉刺激相一致。因此，数据表明，夹带机制在一个界定的通带内操作，使得对于亚三角洲任务节奏，振荡谐波被调用。这些三角洲夹带振荡的相位调制α波段功率。这反过来又可能分别增加或减少对相关和不相关刺激的反应性。
Oscillatory entrainment mechanisms are invoked during attentional processing of rhythmically occurring stimuli, whereby their phase-alignment regulates the excitability state of neurons coding for anticipated inputs. These mechanisms have been examined in the delta-band (1-3 Hz) where entrainment frequency matches the stimulation rate. Here, we investigated entrainment for sub-delta rhythmic stimulation, recording from intracranial electrodes over human auditory cortex during an intersensory audiovisual task. Audiovisual stimuli were presented at 0.67-Hz while participants detected targets within one sensory stream and ignored the other. It was found that entrainment operated at twice the stimulation rate (1.33Hz), and this was reflected by higher amplitude values in the FFT-spectrum, cyclic modulation of alpha-amplitude, and phase-amplitude coupling between delta-phase and alpha-power. In addition, we found that alpha-amplitude was relatively increased in auditory cortex coincident with to-be-ignored auditory stimuli during attention to vision. Thus, the data suggest that entrainment mechanisms operate within a delimited pass-band such that for sub-delta task rhythms, oscillatory harmonics are invoked. The phase of these delta-entrained oscillations modulates alpha-band power. This may in turn increase or decrease responsiveness to relevant and irrelevant stimuli, respectively.