Directional anisotropy of motion responses in retinotopic cortex
Directional anisotropy of motion responses in retinotopic cortex
复制标题
视网膜专题皮层运动反应的方向各向异性
作者：
M. Raemaekers;Martin J. M. Lankheet;S. Moorman;Z. Kourtzi;R. van Wezel
最近，有证据表明早期视觉皮层存在径向取向偏差。这些结果表明，在早期视觉皮层中，运动方向应该存在切向偏倚。我们在一项人体成像研究中测试了这一预测，使用的是一个旋转的随机点图案，在54秒的周期内缓慢旋转其运动方向360°。此外，还进行了极角和偏心映射。这样就可以测量不同视网膜异位区域的BOLD反应。我们发现，在V1， V2和V3中，相对于切向运动，离心和向心运动的BOLD反应一致增强。离心和向心响应偏差的相对大小随视觉偏心率的变化而变化。我们没有发现MT+的运动方向偏差。这些结果与先前观察到的跨视野运动灵敏度的各向异性一致。然而，在早期视觉皮层中观察到径向运动偏差是令人惊讶的，考虑到径向方向偏差的证据。为了解决这个明显的矛盾，我们进行了一个额外的实验。另外的实验表明，观察到的运动方向偏差很可能源于视觉皮层内远距离水平连接的各向异性。Hum Brain map, 2009。©2009 Wiley‐Liss, Inc。
Recently, evidence has emerged for a radial orientation bias in early visual cortex. These results predict that in early visual cortex a tangential bias should be present for motion direction. We tested this prediction in a human imaging study, using a translating random dot pattern that slowly rotated its motion direction 360° in cycles of 54 s. In addition, polar angle and eccentricity mapping were performed. This allowed the measurement of the BOLD response across the visual representations of the different retinotopic areas. We found that, in V1, V2, and V3, BOLD responses were consistently enhanced for centrifugal and centripetal motion, relative to tangential motion. The relative magnitude of the centrifugal and centripetal response biases changed with visual eccentricity. We found no motion direction biases in MT+. These results are in line with previously observed anisotropies in motion sensitivity across the visual field. However, the observation of radial motion biases in early visual cortex is surprising considering the evidence for a radial orientation bias. An additional experiment was performed to resolve this apparent conflict in results. The additional experiment revealed that the observed motion direction biases most likely originate from anisotropies in long range horizontal connections within visual cortex. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
影响因子：
2.5
作者：
FELLEMAN, DJ;VANESSEN, DC
通讯作者：
VANESSEN, DC
影响因子：
2.5
作者：
LEVITT, JB;KIPER, DC;MOVSHON, JA
通讯作者：
MOVSHON, JA
影响因子：
2.5
作者：
ALBRIGHT, TD
通讯作者：
ALBRIGHT, TD