Beckman Institute, University of Illinois at Urbana-Champaign, IL 61801, USA; Psychology Department, University of Illinois at Urbana-Champaign, IL 61820, USA.
Beckman Institute, University of Illinois at Urbana-Champaign, IL 61801, USA.
Neuroimage. 2022 May 15;252:119048. doi: 10.1016/j.neuroimage.2022.119048. Epub 2022 Mar 4.
In the face of multiple sensory streams, there may be competition for processing resources in multimodal cortical areas devoted to establishing representations. In such cases, alpha oscillations may serve to maintain the relevant representations and protect them from interference, whereas theta band activity may facilitate their updating when needed. It can be hypothesized that these oscillations would differ in response to an auditory stimulus when the eyes are open or closed, as intermodal resource competition may be more prominent in the former than in the latter case. Across two studies we investigated the role of alpha and theta power in multimodal competition using an auditory task with the eyes open and closed, respectively enabling and disabling visual processing in parallel with the incoming auditory stream. In a passive listening task (Study 1a), we found alpha suppression following a pip tone with both eyes open and closed, but subsequent alpha enhancement only with closed eyes. We replicated this eyes-closed alpha enhancement in an independent sample (Study 1b). In an active auditory oddball task (Study 2), we again observed the eyes open/eyes closed alpha pattern found in Study 1 and also demonstrated that the more attentionally demanding oddball trials elicited the largest oscillatory effects. Theta power did not interact with eye status in either study. We propose a hypothesis to account for the findings in which alpha may be endemic to multimodal cortical areas in addition to visual ones.
面对多种感觉流，用于建立表示的多模式皮质区域中的处理资源可能存在竞争。在这种情况下，alpha 振荡可能有助于维持相关表示并防止它们受到干扰，而 theta 频带活动可能在需要时促进它们的更新。可以假设，当眼睛睁开或闭着时，这些振荡会因听觉刺激而有所不同，因为在前者中，模态间资源竞争可能比在后一种情况下更为突出。在两项研究中，我们使用分别打开和关闭眼睛的听觉任务，分别在传入的听觉流中启用和禁用视觉处理，研究了 alpha 和 theta 功率在多模态竞争中的作用。在被动听力任务（研究 1a）中，我们发现当眼睛睁开或闭着时，pip 音后都会出现 alpha 抑制，但随后只有闭着眼睛才会出现 alpha 增强。我们在一个独立的样本中复制了这种闭眼时的 alpha 增强（研究 1b）。在主动听觉异常任务（研究 2）中，我们再次观察到研究 1 中发现的睁眼/闭眼 alpha 模式，并且还表明，注意力要求更高的异常试验会引起最大的振荡效应。在这两项研究中，theta 功率都与眼睛状态没有相互作用。我们提出了一个假设来解释这些发现，即 alpha 除了视觉皮质区域外，还可能是多模式皮质区域所特有的。
