Departments of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, QC, Canada.
Eur J Neurosci. 2012 Sep;36(6):2849-58. doi: 10.1111/j.1460-9568.2012.08205.x. Epub 2012 Jul 3.
Plaid stimuli are often used to investigate the mechanisms involved in the integration and segregation of motion information. Considering the perceptual importance of such mechanisms, only a very limited number of visual brain areas have been found to be specifically involved in motion integration. These are the human (h)MT+ complex, area V3 and the pulvinar. The hMT+ complex can be functionally subdivided into two separate areas, middle temporal area (MT) and medial superior temporal area (MST); however, it is currently unclear whether these distinct sub-regions have different responses to plaid stimuli. To address this issue we used functional magnetic resonance imaging to quantify the relative response of MT and MST to component and pattern motion. Participants viewed plaid stimuli that were constrained to result in the perception of either component motion (segregation of motion information) or pattern motion (integration of motion information). MT/MST segregation was achieved using a moving dot stimulus that allowed stimulation of each visual hemifield either in unison or separately. We found pattern motion selective responses in both MT and MST. Consistent with previous reports, activity indicative of pattern motion selectivity was also found in the pulvinar as well as in other extrastriate areas. These results demonstrate that MT, MST and the pulvinar are involved in the complex motion integration mechanisms that are triggered by plaid stimuli. This reinforces the concept that integrative computations take place in a distributed neuronal circuit both in cortical and sub-cortical networks.
棋盘刺激常被用于研究运动信息整合和分离所涉及的机制。考虑到这些机制在知觉上的重要性，只有非常有限的一些视觉脑区被发现专门参与了运动整合。这些脑区包括人类 hMT+ 复合体、V3 区和丘脑枕。hMT+ 复合体可在功能上进一步细分为两个独立的区域，即颞中回（MT）和内侧上颞区（MST）；然而，目前尚不清楚这些不同的亚区对棋盘刺激是否有不同的反应。为了解决这个问题，我们使用功能磁共振成像来量化 MT 和 MST 对成分运动和图案运动的相对反应。参与者观看了受限制的棋盘刺激，这些刺激只能导致成分运动（运动信息的分离）或图案运动（运动信息的整合）的知觉。通过使用允许同时或分别刺激每个视觉半视野的移动点刺激来实现 MT/MST 分离。我们在 MT 和 MST 中都发现了图案运动选择性反应。与之前的报告一致，在丘脑枕以及其他视皮层外区域也发现了与图案运动选择性相关的活动。这些结果表明，MT、MST 和丘脑枕都参与了由棋盘刺激触发的复杂运动整合机制。这进一步证实了整合计算发生在皮质和皮质下网络中分布式神经元回路的概念。
