Bickle J, Bernstein M, Heatley M, Worley C, Stiehl S
Focused Research Program in Computational Neuroscience, Brewster A-335, East Carolina University, Greenville, NC 27858-4353, USA.
J Comput Neurosci. 1999 May-Jun;6(3):251-61. doi: 10.1023/a:1008805922693.
We employ computer simulation to investigate the function of neural circuitries between thalamic sensory relay nuclei, primary sensory cortices, and the thalamic reticular nucleus (TRN). Computational similarities exist between these circuits and the architecture of a simple artificial neural network. We impose processing parameters on this network architecture in keeping with anatomical and physiological details of the mammalian geniculo-cortical visual pathway, and then run the simulation on a task involving multiple simultaneous inputs from the simulated visual field. After two to three loops through the simulation, activity in cortical and thalamic units whose receptive fields include the stronger stimulus remains constant, while activity in other cortical and thalamic units activated by weaker stimuli declines toward resting values. These results suggest that the modeled neural circuitry functions to "prime" selective attentional mechanisms further up the visual streams toward specific portions of the total visual stimulus. Besides extending existing models and evidence about the function of these neural circuits, our results also provide physiologists with predicted activity profiles of thalamic and cortical elements of the modeled neural system for a task not yet studied experimentally.
我们采用计算机模拟来研究丘脑感觉中继核、初级感觉皮层和丘脑网状核（TRN）之间神经回路的功能。这些回路与简单人工神经网络的架构存在计算上的相似性。我们根据哺乳动物膝状体 - 皮层视觉通路的解剖和生理细节，对该网络架构施加处理参数，然后在一个涉及来自模拟视野的多个同时输入的任务上运行模拟。经过两到三轮模拟后，其感受野包含较强刺激的皮层和丘脑单元的活动保持恒定，而由较弱刺激激活的其他皮层和丘脑单元的活动则向静息值下降。这些结果表明，所建模的神经回路起到“启动”作用，使视觉信息流中更高层次的选择性注意机制朝向整个视觉刺激的特定部分。除了扩展关于这些神经回路功能的现有模型和证据外，我们的结果还为生理学家提供了针对一个尚未进行实验研究的任务，所建模的神经系统中丘脑和皮层元件的预测活动概况。
