Characterizing the roles of alpha and theta oscillations in multisensory attention.
Characterizing the roles of alpha and theta oscillations in multisensory attention.
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DOI：
10.1016/j.neuropsychologia.2017.02.021
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发表时间：
2017-05
期刊：
影响因子：
2.6
通讯作者：
Sekuler R
中科院分区：
文献类型：
--
作者：
Keller AS;Payne L;Sekuler R
当只注意到一种感觉模式时，皮层α振荡(8-13赫兹)似乎在抑制分心方面发挥作用，但当注意力分布在多个感觉模式上时，它们也起作用吗？作为一个答案，我们研究了在听觉和视觉序列之间分散注意力的受试者的大脑皮质振荡。在实验1中，受试者执行一项奇怪的任务，在不同的区块中使用听觉、视觉或同时的视听序列，同时使用高密度头皮电极记录脑电。当受试者注意到听觉序列时，阿尔法振荡持续出现在后部区域。这支持了这样一种观点，即大脑抑制视觉输入的处理，以便利用听觉处理。在注意力分散的视听条件下，一种奇怪的(一种罕见的、不寻常的刺激)出现在听觉或视觉领域，要求注意力在这两种模式之间进行分配。在这种视听条件下，当受试者同时监测听觉和视觉序列时，额中枢theta频段(4-7赫兹)的活动最强。Theta振荡与注意力和短期记忆都有关联。实验2试图区分额叶-中枢theta活动在多感觉分离注意中的这些可能的作用。使用实验1中的古怪任务的改进版本，实验2表明，不同条件下的theta能力的差异与短期记忆负荷无关。排除theta与短期记忆的关联，我们得出结论，额叶-中央theta活动可能是多感觉分裂注意力的标志。
Cortical alpha oscillations (8–13 Hz) appear to play a role in suppressing distractions when just one sensory modality is being attended, but do they also contribute when attention is distributed over multiple sensory modalities? For an answer, we examined cortical oscillations in human subjects who were dividing attention between auditory and visual sequences. In Experiment 1, subjects performed an oddball task with auditory, visual, or simultaneous audiovisual sequences in separate blocks, while the electroencephalogram was recorded using high-density scalp electrodes. Alpha oscillations were present continuously over posterior regions while subjects were attending to auditory sequences. This supports the idea that the brain suppresses processing of visual input in order to advantage auditory processing. During a divided-attention audiovisual condition, an oddball (a rare, unusual stimulus) occurred in either the auditory or the visual domain, requiring that attention be divided between the two modalities. Fronto-central theta band (4–7 Hz) activity was strongest in this audiovisual condition, when subjects monitored auditory and visual sequences simultaneously. Theta oscillations have been associated with both attention and with short-term memory. Experiment 2 sought to distinguish these possible roles of fronto-central theta activity during multisensory divided attention. Using a modified version of the oddball task from Experiment 1, Experiment 2 showed that differences in theta power among conditions were independent of short-term memory load. Ruling out theta’s association with short-term memory, we conclude that fronto-central theta activity is likely a marker of multisensory divided attention.