The temporal frequency tuning of human visual cortex investigated using synthetic aperture magnetometry
The temporal frequency tuning of human visual cortex investigated using synthetic aperture magnetometry
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DOI：
10.1016/j.neuroimage.2003.10.045
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发表时间：
2004-04-01
期刊：
影响因子：
5.7
通讯作者：
Singh, KD
中科院分区：
文献类型：
--
作者：
Fawcett, IP;Barnes, GR;Singh, KD
利用合成孔径磁强计（SAM）对脑磁图（MEG）数据进行分析，研究了皮层反应强度和频率随刺激时间频率的变化规律。在两个独立的实验中，在0到21赫兹的频率范围内，在右或左下视野中使用反转棋盘刺激。构建了位于内侧视觉皮层和V5/MT的兴趣区平均时间频率调谐曲线。在内侧视觉皮层，稳态反应的频率和幅度都随着刺激频率的变化而变化，在反应中发现了刺激频率的多重谐波。最大基本响应出现在8赫兹的刺激频率，而最大宽带响应出现在4赫兹。相比之下，诱发的起效反应的幅度和频率内容与刺激频率无关。虽然内侧视觉皮层在刺激期间表现出能量增加，但纹状外区（如V5/MT）表现出双侧事件相关的去同步（ERD）。该ERD的频率内容不依赖于刺激频率，而是在5 - 20 Hz频率范围内的宽带功率降低。在V5/MT范围内，该ERD的幅度对刺激频率具有强烈的低通调谐，并且对对侧视野的刺激仅表现出中度偏好。(C) 2004爱思唯尔公司版权所有。
Using synthetic aperture magnetometry (SAM) analyses of magneto-encephalographic (MEG) data, we investigated the variation in cortical response magnitude and frequency as a function of stimulus temporal frequency. In two separate experiments, a reversing checkerboard stimulus was used in the right or left lower visual field at frequencies from 0 to 21 Hz. Average temporal frequency tuning curves were constructed for regions-of-interest located within medial visual cortex and V5/MT. In medial visual cortex, it was found that both the frequency and magnitude of the steady-state response varied as a function of the stimulus frequency, with multiple harmonies of the stimulus frequency being found in the response. The maximum fundamental response was found at a stimulus frequency of 8 Hz, whilst the maximum broadband response occurred at 4 Hz. In contrast, the magnitude and frequency content of the evoked onset response showed no dependency on stimulus frequency. Whilst medial visual cortex showed a power increase during stimulation, extra-striate areas such as V5/MT exhibited a bilateral event-related desynchronisation (ERD). The frequency content of this ERD did not depend on the stimulus frequency but was a broadband power reduction across the 5 - 20 Hz frequency range. The magnitude of this ERD within V5/MT was strongly low-pass tuned for stimulus frequency, and showed only a moderate preference for stimuli in the contralateral visual field. (C) 2004 Elsevier Inc. All rights reserved.