Disparity-tuned population responses from human visual cortex.
Disparity-tuned population responses from human visual cortex.
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DOI：
10.1523/jneurosci.3795-10.2011
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发表时间：
2011-01-19
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影响因子：
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通讯作者：
Norcia AM
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作者：
Cottereau BR;McKee SP;Ales JM;Norcia AM
我们使用视觉诱发电位源成像来测量大范围水平差（0.5 - 64弧分）内的神经群体反应。刺激是一个中央圆盘，以2hz的频率在注视平面上来回移动，周围要么是双眼不相关的点（视差噪声），要么是注视平面上出现的相关点。磁盘和环绕都由动态随机点组成，以去除相干的单目信息。在单独的功能磁共振成像扫描中定义的五个感兴趣视觉区域（roi） [V1，人类中颞区（hMT+）， V4，外侧枕复合体（LOC）和V3A]中测量视差调节。对于每个ROI中的两种类型的环绕，视差调节功能在2和16 arcmin之间达到峰值。V1 ROI中的视差调谐不受环绕类型的影响，但环绕相关性改变了其他ROI中视差响应的幅度和相位。在V3A和LOC roi中，当磁盘位于环绕面前面时，响应幅度增大，表明这些区域编码了图地关系和目标凹凸性。在hMT+和V4 ROI中，相关环绕在二次谐波处产生一致的相位滞后，但振幅没有变化，而在V3A ROI中，相位和振幅都有影响。因此，对视差环境的敏感性在视觉皮层中普遍存在，但这些环境相互作用的动态在不同区域有所不同。
We used source imaging of visual evoked potentials to measure neural population responses over a wide range of horizontal disparities (0.5– 64 arcmin). The stimulus was a central disk that moved back and forth across the fixation plane at 2 Hz, surrounded either by binocularly uncorrelated dots (disparity noise) or by correlated dots presented in the fixation plane. Both disk and surround were composed of dynamic random dots to remove coherent monocular information. Disparity tuning was measured in five visual regions of interest (ROIs) [V1, human middle temporal area (hMT+), V4, lateral occipital complex (LOC), and V3A], defined in separate functional magnetic resonance imaging scans. The disparity tuning functions peaked between 2 and 16 arcmin for both types of surround in each ROI. Disparity tuning in the V1 ROI was unaffected by the type of surround, but surround correlation altered both the amplitude and phase of the disparity responses in the other ROIs. Response amplitude increased when the disk was in front of the surround in the V3A and LOC ROIs, indicating that these areas encode figure– ground relationships and object convexity. The correlated surround produced a consistent phase lag at the second harmonic in the hMT+ and V4 ROIs without a change in amplitude, while in the V3A ROI, both phase and amplitude effects were observed. Sensitivity to disparity context is thus widespread in visual cortex, but the dynamics of these contextual interactions differ across regions.