Involvement of human primary somatosensory cortex in vibrotactile detection depends on task demand
Involvement of human primary somatosensory cortex in vibrotactile detection depends on task demand
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人类初级体感皮层参与振动触觉检测取决于任务需求
DOI：
10.1016/j.neuroimage.2016.05.056
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发表时间：
2016
期刊：
影响因子：
5.7
通讯作者：
N. Holmes
中科院分区：
文献类型：
--
作者：
Luigi Tamè;N. Holmes
检测和辨别感觉刺激是神经系统的基本功能。电生理学和病变研究表明，猕猴初级体感皮层（SI）在区分刺激方面发挥着至关重要的作用，但并不是简单地检测刺激所必需的。相比之下，人类经颅磁刺激 (TMS) 研究表明，当通过 SI 传递单个 TMS 脉冲时，体感检测几乎完全中断。为了解决这一差异，我们测量了参与者在 SI、未由振动触觉刺激激活的控制部位（顶下小叶，IPL）或远离头部（无 TMS 条件）的情况下使用单独定制的 fMRI 引导 TMS 检测振动触觉刺激的灵敏度和决策标准。在一项单间隔检测任务中，TMS 增加了参与者报告“不存在”目标的可能性，无论地点如何，但 TMS 相对 SI 也降低了检测灵敏度，并阻碍了触觉灵敏度随着时间的推移而提高。然后，我们在一系列两区间强制选择（2IFC）检测和辨别任务中测量了触觉阈值，对反应标准和短期记忆负荷的依赖性较低。我们发现，检测刺激的阈值与 SI 和 IPL 上的 TMS 相当，但 SI 上的 TMS 特别且显着损害了频率辨别力。我们的结论是，根据猕猴研究，人类 SI 是区分触觉刺激以及随着时间的推移或在高任务要求下维持刺激表征所必需的，但简单的触觉检测可能不需要。重要的陈述对猴子的研究表明，初级体感皮层负责区分指尖上的不同振动，但不仅仅是检测这些振动。然而，对人类的类似研究表明，体感皮层对于检测和区分触觉刺激是必需的。我们使用磁脑刺激来干扰人类体感皮层，同时健康志愿者检测并区分施加到指尖的振动。我们发现，体感皮层需要在短时间内将振动触觉刺激保留在记忆中并比较两个振动触觉刺激，但不仅仅需要检测振动触觉刺激。这表明振动触觉检测并不总是需要人类初级体感皮层。
Detecting and discriminating sensory stimuli are fundamental functions of the nervous system. Electrophysiological and lesion studies suggest that macaque primary somatosensory cortex (SI) is critically involved in discriminating between stimuli, but is not required simply for detecting stimuli. By contrast, transcranial magnetic stimulation (TMS) studies in humans have shown near-complete disruption of somatosensory detection when a single pulse of TMS is delivered over SI. To address this discrepancy, we measured the sensitivity and decision criteria of participants detecting vibrotactile stimuli with individually-tailored fMRI-guided TMS over SI, over a control site not activated by vibrotactile stimuli (inferior parietal lobule, IPL), or away from the head (a no TMS condition). In a one-interval detection task, TMS increased participants' likelihood of reporting ‘no’ target present regardless of site, but TMS over SI also decreased detection sensitivity, and prevented improvement in tactile sensitivity over time. We then measured tactile thresholds in a series of two-interval forced-choice (2IFC) detection and discrimination tasks with lower dependence on response criteria and short-term memory load. We found that thresholds for detecting stimuli were comparable with TMS over SI and IPL, but TMS over SI specifically and significantly impaired frequency discrimination. We conclude that, in accordance with macaque studies, human SI is required for discriminating between tactile stimuli and for maintaining stimulus representations over time, or under high task demand, but may not be required for simple tactile detection.Significant statementStudies on monkeys have suggested that the primary somatosensory cortex is responsible for discriminating between different vibrations on the fingertips, but not just for detecting these vibrations. However, similar studies in humans suggest that the somatosensory cortex is required both for detecting and discriminating between tactile stimuli. We used magnetic brain stimulation to interfere with human somatosensory cortex while healthy volunteers detected and discriminated between vibrations applied to their fingertips. We found that the somatosensory cortex is required for keeping vibrotactile stimuli in memory for short periods of time and for comparing two vibrotactile stimuli, but is not required merely for detecting vibrotactile stimulation. This suggests that human primary somatosensory cortex is not always needed for vibrotactile detection.
影响因子：
2.8
作者：
Song,Sunbin;Sandrini,Marco;Cohen,LeonardoG
通讯作者：
Cohen,LeonardoG
影响因子：
--
作者：
Brainard, DH
通讯作者：
Brainard, DH
影响因子：
3.7
作者：
Katus, Tobias;Grubert, Anna;Eimer, Martin
通讯作者：
Eimer, Martin