文章基本信息

标题：Mapping human temporal and parietal neuronal population activity and functional coupling during mathematical cognition
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作者：Amy L. Daitch ; Brett L. Foster ; Jessica Schrouff 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2016
卷号：113
期号：46
页码：E7277-E7286
DOI：10.1073/pnas.1608434113
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceHumans have the unique ability to perform exact mental arithmetic, which derives from the association of symbols (e.g., "3") with discrete quantities. Using direct intracranial recordings, we measured electrophysiological activity from neuronal populations in the lateral parietal cortex (LPC) and ventral temporal cortex (VTC) that are known to be important for numerical processing as subjects performed various experiments. We observed functional heterogeneity within each region at the millimeter and millisecond scales and report empirical evidence of functional coupling between the LPC and VTC during mathematical cognition. Our results suggest the presence of an anatomically selective numerical cognition system that engages discrete neuronal populations of the ventral temporal and lateral parietal regions in different time windows of numerical processing. Brain areas within the lateral parietal cortex (LPC) and ventral temporal cortex (VTC) have been shown to code for abstract quantity representations and for symbolic numerical representations, respectively. To explore the fast dynamics of activity within each region and the interaction between them, we used electrocorticography recordings from 16 neurosurgical subjects implanted with grids of electrodes over these two regions and tracked the activity within and between the regions as subjects performed three different numerical tasks. Although our results reconfirm the presence of math-selective hubs within the VTC and LPC, we report here a remarkable heterogeneity of neural responses within each region at both millimeter and millisecond scales. Moreover, we show that the heterogeneity of response profiles within each hub mirrors the distinct patterns of functional coupling between them. Our results support the existence of multiple bidirectional functional loops operating between discrete populations of neurons within the VTC and LPC during the visual processing of numerals and the performance of arithmetic functions. These findings reveal information about the dynamics of numerical processing in the brain and also provide insight into the fine-grained functional architecture and connectivity within the human brain.
关键词：numerical processing ; ECoG ; brain network ; parietal cortex ; ventral temporal cortex