Noel Jean-Paul, Balzani Edoardo, Savin Cristina, Angelaki Dora E
Center for Neural Science, New York University, New York City, NY, USA.
bioRxiv. 2023 Jul 31:2023.07.30.551169. doi: 10.1101/2023.07.30.551169.
Natural behaviors occur in closed action-perception loops and are supported by dynamic and flexible beliefs abstracted away from our immediate sensory milieu. How this real-world flexibility is instantiated in neural circuits remains unknown. Here we have macaques navigate in a virtual environment by primarily leveraging sensory (optic flow) signals, or by more heavily relying on acquired internal models. We record single-unit spiking activity simultaneously from the dorsomedial superior temporal area (MSTd), parietal area 7a, and the dorso-lateral prefrontal cortex (dlPFC). Results show that while animals were able to maintain adaptive task-relevant beliefs regardless of sensory context, the fine-grain statistical dependencies between neurons, particularly in 7a and dlPFC, dynamically remapped with the changing computational demands. In dlPFC, but not 7a, destroying these statistical dependencies abolished the area's ability for cross-context decoding. Lastly, correlation analyses suggested that the more unit-to-unit couplings remapped in dlPFC, and the less they did so in MSTd, the less were population codes and behavior impacted by the loss of sensory evidence. We conclude that dynamic functional connectivity between prefrontal cortex neurons maintains a stable population code and context-invariant beliefs during naturalistic behavior with closed action-perception loops.
自然行为发生在封闭的动作-感知循环中，并由从我们即时的感觉环境中抽象出来的动态灵活信念所支持。这种现实世界中的灵活性如何在神经回路中体现仍然未知。在这里，我们让猕猴在虚拟环境中导航，主要通过利用感觉（光流）信号，或者更多地依赖于习得的内部模型。我们同时记录了背内侧颞上区（MSTd）、顶叶7a区和背外侧前额叶皮层（dlPFC）的单神经元放电活动。结果表明，虽然动物能够在不考虑感觉环境的情况下维持与任务相关的适应性信念，但神经元之间的细粒度统计依赖性，特别是在7a区和dlPFC中，会随着计算需求的变化而动态重新映射。在dlPFC而不是7a区，破坏这些统计依赖性会消除该区域的跨环境解码能力。最后，相关性分析表明，dlPFC中单元间耦合重新映射得越多，MSTd中越少，群体编码和行为受感觉证据丧失的影响就越小。我们得出结论，前额叶皮层神经元之间的动态功能连接在具有封闭动作-感知循环的自然行为过程中维持稳定的群体编码和情境不变信念。
