Causal roles of prefrontal cortex during spontaneous perceptual switching are determined by brain state dynamics.
Causal roles of prefrontal cortex during spontaneous perceptual switching are determined by brain state dynamics.
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前额叶皮层在自发知觉转换过程中的因果作用是由大脑状态动力学决定的。
DOI：
10.7554/elife.69079
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发表时间：
2021-10-29
期刊：
影响因子：
7.7
通讯作者：
Watanabe T
中科院分区：
文献类型：
--
作者：
Watanabe T
前额叶皮层（PFC）被认为是协调认知动力学的。然而，在视觉感知测试中，除了最近的一项工作外，没有直接证据支持PFC的这种假定因果作用。在这里，使用一种新的脑状态依赖的神经刺激系统，我们确定了因果关系的影响，在三个PFC活动，右额叶眼场，背外侧PFC（DLPFC），和下额叶皮层（IFC）的动态。只有当我们跟踪大脑状态动态并以大脑状态/状态历史依赖的方式调节PFC活动时，因果关系才能在行为上检测到。行为效应是由大脑状态动力学中的瞬时神经变化支撑的，并且这种神经效应可以通过假设的能量景观的结构转换来定量解释。此外，这些研究结果表明，PFC的三个领域的不同功能：特别是，DLPFC增强两个PFC活跃的大脑状态的整合，而IFC促进它们之间的功能隔离。这项工作解决了有关PFC在自发感知切换中的作用的争议，并强调了大脑行为因果关系的精细调查中的大脑状态动力学。一个立方体，似乎改变其空间安排，因为你继续看;优雅的剪影旋转舞者，它开始在相反的方向旋转，你盯着它;一个插图，显示两个侧面-或者是一个花瓶？这些视错觉是视觉感知的例子。除了它们的娱乐性之外，它们还为科学家提供了一种探索人类意识动态以及参与这一过程的神经区域的方法。一些研究表明，视觉感知与前额叶皮层的激活有关，前额叶皮层是一个参与复杂认知过程的大脑区域。然而，目前还不清楚这个区域是否是出现幻觉所必需的。一些研究表明，即使部分前额叶皮层暂时失活，参与者仍然可以体验到幻觉。相反，渡边孝光提出，波动性视觉感知是一个与动态大脑状态相关的过程--也就是说，这种波动性视觉感知需要前额叶皮层的不同区域，这取决于整个大脑的状态。如果不密切跟踪大脑活动，就无法观察到这种因果关系。为了研究这一点，65名参与者在经历视错觉时的大脑状态被记录下来;因此，他们各个大脑区域的活动可以被映射出来，然后前额皮质的区域可以在正确的时间使用经颅磁刺激精确地被抑制。这表明，前额叶皮层区域确实是视觉感知所必需的，但不是以一种简单的方式。相反，哪些是必需的，何时需要取决于整个大脑中发生的活动动力学。总的来说，这些结果表明，监测大脑状态是必要的，以更好地理解-并最终控制-感知和行为的神经通路。
The prefrontal cortex (PFC) is thought to orchestrate cognitive dynamics. However, in tests of bistable visual perception, no direct evidence supporting such presumable causal roles of the PFC has been reported except for a recent work. Here, using a novel brain-state-dependent neural stimulation system, we identified causal effects on percept dynamics in three PFC activities—right frontal eye fields, dorsolateral PFC (DLPFC), and inferior frontal cortex (IFC). The causality is behaviourally detectable only when we track brain state dynamics and modulate the PFC activity in brain-state-/state-history-dependent manners. The behavioural effects are underpinned by transient neural changes in the brain state dynamics, and such neural effects are quantitatively explainable by structural transformations of the hypothetical energy landscapes. Moreover, these findings indicate distinct functions of the three PFC areas: in particular, the DLPFC enhances the integration of two PFC-active brain states, whereas IFC promotes the functional segregation between them. This work resolves the controversy over the PFC roles in spontaneous perceptual switching and underlines brain state dynamics in fine investigations of brain-behaviour causality. A cube that seems to shift its spatial arrangement as you keep looking; the elegant silhouette of a pirouetting dancer, which starts to spin in the opposite direction the more you stare at it; an illustration that shows two profiles – or is it a vase? These optical illusions are examples of bistable visual perception. Beyond their entertaining aspect, they provide a way for scientists to explore the dynamics of human consciousness, and the neural regions involved in this process. Some studies show that bistable visual perception is associated with the activation of the prefrontal cortex, a brain area involved in complex cognitive processes. However, it is unclear whether this region is required for the illusions to emerge. Some research has showed that even if sections of the prefrontal cortex are temporally deactivated, participants can still experience the illusions. Instead, Takamitsu Watanabe proposes that bistable visual perception is a process tied to dynamic brain states – that is, that distinct regions of the prefontal cortex are required for this fluctuating visual awareness, depending on the state of the whole brain. Such causal link cannot be observed if brain activity is not tracked closely. To investigate this, the brain states of 65 participants were recorded as individuals were experiencing the optical illusions; the activity of their various brain regions could therefore be mapped, and then areas of the prefrontal cortex could precisely be inhibited at the right time using transcranial magnetic stimulation. This revealed that, indeed, prefrontal cortex regions were necessary for bistable visual perception, but not in a simple way. Instead, which ones were required and when depended on activity dynamics taking place in the whole brain. Overall, these results indicate that monitoring brain states is necessary to better understand – and ultimately, control – the neural pathways underlying perception and behaviour.