The Sheryl and Daniel R. Tishman Cognitive Neurophysiology Laboratory, Department of Pediatrics, Children's Evaluation and Rehabilitation Center (CERC), Albert Einstein College of Medicine & Children's Hospital at Montefiore, Van Etten Building - Wing 1C, 1225 Morris Park Avenue, Bronx, NY, 10461, USA; Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA; The Cognitive Neurophysiology Laboratory, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, USA; Program in Cognitive Neuroscience, Departments of Psychology & Biology, City College of the City University of New York, New York, NY, USA.
Eur J Neurosci. 2014 Jun;39(11):1960-72. doi: 10.1111/ejn.12577. Epub 2014 Apr 1.
We assessed the role of alpha-band oscillatory activity during a task-switching design that required participants to switch between an auditory and a visual task, while task-relevant audiovisual inputs were simultaneously presented. Instructional cues informed participants which task to perform on a given trial and we assessed alpha-band power in the short 1.35-s period intervening between the cue and the task-imperative stimuli, on the premise that attentional biasing mechanisms would be deployed to resolve competition between the auditory and visual inputs. Prior work had shown that alpha-band activity was differentially deployed depending on the modality of the cued task. Here, we asked whether this activity would, in turn, be differentially deployed depending on whether participants had just made a switch of task or were being asked to simply repeat the task. It is well established that performance speed and accuracy are poorer on switch than on repeat trials. Here, however, the use of instructional cues completely mitigated these classic switch-costs. Measures of alpha-band synchronisation and desynchronisation showed that there was indeed greater and earlier differential deployment of alpha-band activity on switch vs. repeat trials. Contrary to our hypothesis, this differential effect was entirely due to changes in the amount of desynchronisation observed during switch and repeat trials of the visual task, with more desynchronisation over both posterior and frontal scalp regions during switch-visual trials. These data imply that particularly vigorous, and essentially fully effective, anticipatory biasing mechanisms resolved the competition between competing auditory and visual inputs when a rapid switch of task was required.
我们评估了在一项任务切换设计中的 alpha 波段振荡活动的作用，该设计要求参与者在同时呈现听觉和视觉任务相关输入的情况下在听觉和视觉任务之间切换。指导线索告知参与者在给定试验中要执行的任务，我们评估了在线索和任务指令刺激之间短暂的 1.35 秒期间的 alpha 波段功率，前提是注意力偏向机制将被部署以解决听觉和视觉输入之间的竞争。先前的工作表明，alpha 波段活动根据提示任务的模态而不同地部署。在这里，我们询问这种活动是否会根据参与者刚刚进行任务切换还是被要求简单地重复任务而不同地部署。众所周知，在切换试验中，性能速度和准确性比重复试验差。然而，在这里，使用指导线索完全减轻了这些经典的切换成本。alpha 波段同步和去同步的测量表明，在切换与重复试验中，alpha 波段活动确实存在更大和更早的差异部署。与我们的假设相反，这种差异效应完全归因于在视觉任务的切换和重复试验中观察到的去同步量的变化，在切换视觉试验中，在后头部和额头部区域都有更多的去同步。这些数据意味着，当需要快速切换任务时，特别有力且本质上完全有效的预测性偏向机制解决了竞争的听觉和视觉输入之间的竞争。
