Brouwer Gijs Joost, van Ee Raymond
Helmholtz Institute, University of Utrecht, 3584 CC Utrecht, The Netherlands.
J Neurosci. 2007 Jan 31;27(5):1015-23. doi: 10.1523/JNEUROSCI.4593-06.2007.
We investigated the role of retinotopic visual cortex and motion-sensitive areas in representing the content of visual awareness during ambiguous structure-from-motion (SFM), using functional magnetic resonance imaging (fMRI) and multivariate statistics (support vector machines). Our results indicate that prediction of perceptual states can be very accurate for data taken from dorsal visual areas V3A, V4D, V7, and MT+ and for parietal areas responsive to SFM, but to a lesser extent for other visual areas. Generalization of prediction was possible, because prediction accuracy was significantly better than chance for both an unambiguous stimulus and a different experimental design. Detailed analysis of eye movements revealed that strategic and even encouraged beneficial eye movements were not the cause of the prediction accuracy based on cortical activation. We conclude that during perceptual rivalry, neural correlates of visual awareness can be found in retinotopic visual cortex, MT+, and parietal cortex. We argue that the organization of specific motion-sensitive neurons creates detectable biases in the preferred direction selectivity of voxels, allowing prediction of perceptual states. During perceptual rivalry, retinotopic visual cortex, in particular higher-tier dorsal areas like V3A and V7, actively represents the content the visual awareness.
我们使用功能磁共振成像(fMRI)和多变量统计(支持向量机),研究了视网膜拓扑视觉皮层和运动敏感区域在模糊的运动结构(SFM)过程中对视觉意识内容的表征作用。我们的结果表明,对于取自背侧视觉区域V3A、V4D、V7和MT+以及对SFM有反应的顶叶区域的数据,感知状态的预测可以非常准确,但对于其他视觉区域,预测的准确性则较低。预测的泛化是可能的,因为对于明确的刺激和不同的实验设计,预测准确性都显著高于随机水平。对眼动的详细分析表明,策略性的甚至是被鼓励的有益眼动并不是基于皮层激活的预测准确性的原因。我们得出结论,在感知竞争过程中,视觉意识的神经关联可以在视网膜拓扑视觉皮层、MT+和顶叶皮层中找到。我们认为,特定运动敏感神经元的组织在体素的偏好方向选择性上产生了可检测的偏差,从而使得感知状态的预测成为可能。在感知竞争过程中,视网膜拓扑视觉皮层,特别是像V3A和V7这样的高级背侧区域,积极地表征视觉意识的内容。