Center for Brain and Cognition, Computational Neuroscience Group, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Roc Boronat 138, Barcelona, 08018, Spain.
Center for Brain and Cognition, Computational Neuroscience Group, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Roc Boronat 138, Barcelona, 08018, Spain; Institució Catalana de la Recerca i Estudis Avanats (ICREA), Universitat Pompeu Fabra, Passeig Lluís Companys 23, Barcelona, 08010, Spain.
Neuroimage. 2018 Oct 15;180(Pt B):534-546. doi: 10.1016/j.neuroimage.2017.09.061. Epub 2017 Oct 9.
Our behavior entails a flexible and context-sensitive interplay between brain areas to integrate information according to goal-directed requirements. However, the neural mechanisms governing the entrainment of functionally specialized brain areas remain poorly understood. In particular, the question arises whether observed changes in the regional activity for different cognitive conditions are explained by modifications of the inputs to the brain or its connectivity? We observe that transitions of fMRI activity between areas convey information about the tasks performed by 19 subjects, watching a movie versus a black screen (rest). We use a model-based framework that explains this spatiotemporal functional connectivity pattern by the local variability for 66 cortical regions and the network effective connectivity between them. We find that, among the estimated model parameters, movie viewing affects to a larger extent the local activity, which we interpret as extrinsic changes related to the increased stimulus load. However, detailed changes in the effective connectivity preserve a balance in the propagating activity and select specific pathways such that high-level brain regions integrate visual and auditory information, in particular boosting the communication between the two brain hemispheres. These findings speak to a dynamic coordination underlying the functional integration in the brain.
我们的行为需要大脑区域之间灵活和敏感的相互作用，根据目标导向的要求整合信息。然而，控制功能专业化大脑区域同步的神经机制仍知之甚少。特别是，人们提出了这样一个问题：对于不同的认知条件，观察到的区域活动变化是否可以通过大脑输入或其连通性的改变来解释？我们观察到，fmri 活动在不同区域之间的转换传递了 19 名受试者执行任务的信息，观看电影与观看黑屏（休息）。我们使用基于模型的框架来解释这种时空功能连接模式，该模型由 66 个皮质区域的局部可变性和它们之间的网络有效连接性来解释。我们发现，在所估计的模型参数中，观看电影在更大程度上影响局部活动，我们将其解释为与刺激负荷增加相关的外在变化。然而，有效连接的详细变化保持了传播活动的平衡，并选择了特定的路径，使得高级大脑区域整合视觉和听觉信息，特别是增强了两个大脑半球之间的通信。这些发现反映了大脑功能整合背后的动态协调。
