Frontoparietal Cortex Mediates Perceptual Transitions in Bistable Perception
Frontoparietal Cortex Mediates Perceptual Transitions in Bistable Perception
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DOI：
10.1523/jneurosci.1418-13.2013
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发表时间：
2013-10-02
影响因子：
5.3
通讯作者：
Sterzer, Philipp
中科院分区：
文献类型：
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作者：
Weilnhammer, Veith A.;Ludwig, Karin;Sterzer, Philipp
在双稳态视觉中，知觉在两个相互排斥的知觉之间振荡，尽管有持续的感觉输入。与在知觉质量和时间上与双稳态紧密匹配的“重放”转变相比，额顶皮质中更大的大胆反应被证明与内源性知觉转变有关。然而，这种增强的活动是否反映了这些区域对感觉水平加工的因果影响，还是刺激差异的影响，例如，与重放条件相比，导致双稳态知觉转换的持续时间更长，这一点仍然存在争议。在对15名人类参与者进行的fMRI实验中，我们使用旋转的李萨如图形，控制了转换持续时间差异的潜在混淆，并证实了之前的发现，即在双稳态感知过程中，额顶区的转换活动更活跃。此外，我们应用动态因果模型来确定在有效连通性方面最好地解释观察到的粗体信号的神经模型。我们发现，知觉转换的活动增强与从额叶到视觉皮质的自上而下的连接的调制有关，从而论证了额顶皮质在双稳态知觉转换中的关键作用。
During bistable vision, perception oscillates between two mutually exclusive percepts despite constant sensory input. Greater BOLD responses in frontoparietal cortex have been shown to be associated with endogenous perceptual transitions compared with "replay" transitions designed to closely match bistability in both perceptual quality and timing. It has remained controversial, however, whether this enhanced activity reflects causal influences of these regions on processing at the sensory level or, alternatively, an effect of stimulus differences that result in, for example, longer durations of perceptual transitions in bistable perception compared with replay conditions. Using a rotating Lissajous figure in an fMRI experiment on 15 human participants, we controlled for potential confounds of differences in transition duration and confirmed previous findings of greater activity in frontoparietal areas for transitions during bistable perception. In addition, we applied dynamic causal modeling to identify the neural model that best explains the observed BOLD signals in terms of effective connectivity. We found that enhanced activity for perceptual transitions is associated with a modulation of top-down connectivity from frontal to visual cortex, thus arguing for a crucial role of frontoparietal cortex in perceptual transitions during bistable perception.