Cross-Hemispheric Complementary Prefrontal Mechanisms during Task Switching under Perceptual Uncertainty
Cross-Hemispheric Complementary Prefrontal Mechanisms during Task Switching under Perceptual Uncertainty
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DOI：
10.1523/jneurosci.2096-20.2021
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发表时间：
2021-01
期刊：
影响因子：
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通讯作者：
Kaho Tsumura;R. Aoki;Masaki Takeda;K. Nakahara;K. Jimura
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作者：
Kaho Tsumura;R. Aoki;Masaki Takeda;K. Nakahara;K. Jimura
灵活适应变化的环境是一个代表性的执行控制功能，涉及额顶叶网络，需要适当的提取目标相关的信息，通过感知外部环境。然而，在与目标相关的信息不确定的情况下，如何实现灵活性仍不清楚。为了解决这个问题，本研究探讨了任务转换的神经机制，其中任务相关的信息涉及知觉的不确定性。28名男女人类参与者交替进行行为任务，在这些任务中，他们判断随机移动的视觉呈现的彩色点刺激的运动方向或颜色。任务转换与左半球的额顶叶区域有关，对模糊刺激的感知涉及对侧同源额顶叶区域。另一方面，在刺激通道依赖的枕颞区，任务编码信息增加，在任务切换。有效的连接性分析表明，额叶区域向模态依赖性枕颞区的信号时，相关的刺激是更模糊的，而枕颞区向额叶区域的信号时，刺激更独特。这些结果表明，当外部环境涉及知觉不确定性时，左右半球的互补前额叶机制有助于实现行为目标。在我们的日常生活中，实现目标的环境信息并不总是确定的，但我们在这种情况下做出判断，并相应地改变我们的行为。本研究探讨了在目标相关信息涉及知觉不确定性的情况下，行为的灵活性是如何实现的。功能磁共振成像显示，在左半球的外侧前额叶皮层（PFC）与行为的灵活性，和模糊刺激的知觉涉及在右半球的PFC。这些双边PFC信号刺激模态依赖枕颞区，这取决于知觉的不确定性和要执行的任务。这些自上而下的信号补充了枕颞区的任务编码，并强调了执行控制和知觉决策中涉及的大脑半球间前额叶机制。
Flexible adaptation to changing environments is a representative executive control function implicated in the frontoparietal network that requires appropriate extraction of goal-relevant information through perception of the external environment. It remains unclear, however, how the flexibility is achieved under situations where goal-relevant information is uncertain. To address this issue, the current study examined neural mechanisms for task switching in which task-relevant information involved perceptual uncertainty. Twenty-eight human participants of both sexes alternated behavioral tasks in which they judged motion direction or color of visually presented colored dot stimuli that moved randomly. Task switching was associated with frontoparietal regions in the left hemisphere, and perception of ambiguous stimuli involved contralateral homologous frontoparietal regions. On the other hand, in stimulus-modality-dependent occipitotemporal regions, task coding information was increased during task switching. Effective connectivity analysis revealed that the frontal regions signaled toward the modality-dependent occipitotemporal regions when a relevant stimulus was more ambiguous, whereas the occipitotemporal regions signaled toward the frontal regions when the stimulus was more distinctive. These results suggest that complementary prefrontal mechanisms in the left and right hemispheres help to achieve a behavioral goal when the external environment involves perceptual uncertainty. SIGNIFICANCE STATEMENT In our daily life, environmental information to achieve a goal is not always certain, but we make judgments in such situations, and change our behavior accordingly. This study examined how the flexibility of behavior is achieved in a situation where goal-relevant information involves perceptual uncertainty. fMRI revealed that the lateral prefrontal cortex (PFC) in the left hemisphere is associated with behavioral flexibility, and the perception of ambiguous stimuli involves the PFC in the right hemisphere. These bilateral PFC signaled to stimulus-modality-dependent occipitotemporal regions, depending on perceptual uncertainty and the task to be performed. These top-down signals supplement task coding in the occipitotemporal regions, and highlight interhemispheric prefrontal mechanisms involved in executive control and perceptual decision-making.