Department of Kinesiology, University of Waterloo, Ontario, Canada.
Hum Brain Mapp. 2010 Jan;31(1):14-25. doi: 10.1002/hbm.20841.
Previous research has shown that information from one sensory modality has the potential to influence activity in a different modality, and these crossmodal interactions can occur early in the cortical sensory processing stream within sensory-specific cortex. In addition, it has been shown that when sensory information is relevant to the performance of a task, there is an upregulation of sensory cortex. This study sought to investigate the effects of simultaneous bimodal (visual and vibrotactile) stimulation on the modulation of primary somatosensory cortex (SI), in the context of a delayed sensory-to-motor task when both stimuli are task-relevant. It was hypothesized that the requirement to combine visual and vibrotactile stimuli would be associated with an increase in SI activity compared to vibrotactile stimuli alone. Functional magnetic resonance imaging (fMRI) was performed on healthy subjects using a 3T scanner. During the scanning session, subjects performed a sensory-guided motor task while receiving visual, vibrotactile, or both types of stimuli. An event-related design was used to examine cortical activity related to the stimulus onset and the motor response. A region of interest (ROI) analysis was performed on right SI and revealed an increase in percent blood oxygenation level dependent signal change in the bimodal (visual + tactile) task compared to the unimodal tasks. Results of the whole-brain analysis revealed a common fronto-parietal network that was active across both the bimodal and unimodal task conditions, suggesting that these regions are sensitive to the attentional and motor-planning aspects of the task rather than the unimodal or bimodal nature of the stimuli.
先前的研究表明，一种感觉模态的信息有可能影响另一种感觉模态的活动，并且这些跨感觉模态的相互作用可以在感觉特异性皮层的皮质感觉处理流的早期发生。此外，已经表明，当感觉信息与任务的执行相关时，感觉皮层会被上调。本研究旨在探讨在与任务相关的延迟感觉-运动任务中，当两种刺激均与任务相关时，同时进行双模态（视觉和振动触觉）刺激对初级体感皮层（SI）调制的影响。假设与单独的振动触觉刺激相比，需要结合视觉和振动触觉刺激会与 SI 活动的增加相关。使用 3T 扫描仪对健康受试者进行功能磁共振成像（fMRI）。在扫描过程中，受试者在接收视觉、振动触觉或两种类型的刺激时执行感觉引导的运动任务。采用事件相关设计来检查与刺激开始和运动反应相关的皮质活动。对右侧 SI 进行了感兴趣区域（ROI）分析，结果显示在双模态（视觉+触觉）任务中，与单模态任务相比，血氧水平依赖信号变化的百分比增加。全脑分析的结果揭示了一个共同的额顶叶网络，该网络在双模态和单模态任务条件下均活跃，这表明这些区域对任务的注意力和运动计划方面敏感，而不是对刺激的单模态或双模态性质敏感。
