Hierarchy of direction-tuned motion adaptation in human visual cortex.
Hierarchy of direction-tuned motion adaptation in human visual cortex.
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DOI：
10.1152/jn.00923.2010
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发表时间：
2012-04
影响因子：
2.5
通讯作者：
Hyun Ah Lee;Sang-Hun Lee
中科院分区：
文献类型：
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作者：
Hyun Ah Lee;Sang-Hun Lee
长时间暴露于单一运动方向会改变对后续静态或动态刺激的感知，并引起运动敏感神经元行为的实质性变化，但人脑中神经适应的起源以及运动适应感知结果的神经相关性仍不清楚。使用功能磁共振成像，我们通过探测相对于适应方向的一系列方向适应后皮层活动的变化来测量精细尺度的运动适应调谐曲线。我们发现调节曲线形状存在明显的二分性：早期视觉区域的皮层反应在适应方向和相反方向周围均减少，导致双向调节曲线，而高层区域的反应减少仅发生在适应方向周围，导致单向调节曲线。我们还发现，心理物理学测量的适应调谐曲线是单向的，并且与中颞区（MT）和内侧上颞区（MST）的皮质适应调谐曲线最匹配。我们的研究结果符合但不限于以下解释：运动适应的直接影响发生在早期视觉区域的单向和双向单元中，但运动适应的感知后果体现在 MT 和 MST 的群体活动中，这可能继承了方向选择单元的适应的直接影响。
Prolonged exposure to a single direction of motion alters perception of subsequent static or dynamic stimuli and induces substantial changes in behaviors of motion-sensitive neurons, but the origin of neural adaptation and neural correlates of perceptual consequences of motion adaptation in human brain remain unclear. Using functional magnetic resonance imaging, we measured motion adaptation tuning curves in a fine scale by probing changes in cortical activity after adaptation for a range of directions relative to the adapted direction. We found a clear dichotomy in tuning curve shape: cortical responses in early-tier visual areas reduced at around both the adapted and opposite direction, resulting in a bidirectional tuning curve, whereas response reduction in high-tier areas occurred only at around the adapted direction, resulting in a unidirectional tuning curve. We also found that the psychophysically measured adaptation tuning curves were unidirectional and best matched the cortical adaptation tuning curves in the middle temporal area (MT) and the medial superior temporal area (MST). Our findings are compatible with, but not limited to, an interpretation in which direct impacts of motion adaptation occur in both unidirectional and bidirectional units in early visual areas, but the perceptual consequences of motion adaptation are manifested in the population activity in MT and MST, which may inherit those direct impacts of adaptation from the directionally selective units.