Göschl Florian, Friese Uwe, Daume Jonathan, König Peter, Engel Andreas K
Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany.
Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany.
Neuroimage. 2015 Aug 1;116:177-86. doi: 10.1016/j.neuroimage.2015.03.067. Epub 2015 Apr 3.
Coherent percepts emerge from the accurate combination of inputs from the different sensory systems. There is an ongoing debate about the neurophysiological mechanisms of crossmodal interactions in the brain, and it has been proposed that transient synchronization of neurons might be of central importance. Oscillatory activity in lower frequency ranges (<30Hz) has been implicated in mediating long-range communication as typically studied in multisensory research. In the current study, we recorded high-density electroencephalograms while human participants were engaged in a visuotactile pattern matching paradigm and analyzed oscillatory power in the theta- (4-7Hz), alpha- (8-13Hz) and beta-bands (13-30Hz). Employing the same physical stimuli, separate tasks of the experiment either required the detection of predefined targets in visual and tactile modalities or the explicit evaluation of crossmodal stimulus congruence. Analysis of the behavioral data showed benefits for congruent visuotactile stimulus combinations. Differences in oscillatory dynamics related to crossmodal congruence within the two tasks were observed in the beta-band for crossmodal target detection, as well as in the theta-band for congruence evaluation. Contrasting ongoing activity preceding visuotactile stimulation between the two tasks revealed differences in the alpha- and beta-bands. Source reconstruction of between-task differences showed prominent involvement of premotor cortex, supplementary motor area, somatosensory association cortex and the supramarginal gyrus. These areas not only exhibited more involvement in the pre-stimulus interval for target detection compared to congruence evaluation, but were also crucially involved in post-stimulus differences related to crossmodal stimulus congruence within the detection task. These results add to the increasing evidence that low frequency oscillations are functionally relevant for integration in distributed brain networks, as demonstrated for crossmodal interactions in visuotactile pattern matching in the current study.
连贯的感知源于不同感觉系统输入的精确组合。关于大脑中跨模态相互作用的神经生理机制一直存在争论，有人提出神经元的瞬态同步可能至关重要。低频范围（<30Hz）的振荡活动被认为在介导多感官研究中通常所研究的远距离通信中起作用。在本研究中，我们在人类参与者进行视觉触觉模式匹配范式时记录了高密度脑电图，并分析了θ波（4 - 7Hz）、α波（8 - 13Hz）和β波频段（13 - 30Hz）的振荡功率。使用相同的物理刺激，实验的不同任务要么要求检测视觉和触觉模态中的预定义目标，要么要求明确评估跨模态刺激的一致性。行为数据分析显示，一致的视觉触觉刺激组合具有优势。在跨模态目标检测的β频段以及一致性评估的θ频段中，观察到了与两个任务中跨模态一致性相关的振荡动力学差异。对比两个任务中视觉触觉刺激之前的持续活动，发现α波和β波频段存在差异。任务间差异的源重建显示，运动前皮质、辅助运动区、体感联合皮质和缘上回有显著参与。这些区域不仅在目标检测的刺激前间隔中比一致性评估表现出更多参与，而且在检测任务中与跨模态刺激一致性相关的刺激后差异中也至关重要。这些结果进一步证明了低频振荡在分布式脑网络整合中具有功能相关性，正如本研究中视觉触觉模式匹配中的跨模态相互作用所证明的那样。
