University of Hong Kong, Hong Kong.
J Cogn Neurosci. 2013 Jul;25(7):998-1007. doi: 10.1162/jocn_a_00377. Epub 2013 Feb 28.
Hemispheric asymmetry in the processing of local and global features has been argued to originate from differences in frequency filtering in the two hemispheres, with little neurophysiological support. Here we test the hypothesis that this asymmetry takes place at an encoding stage beyond the sensory level, due to asymmetries in anatomical connections within each hemisphere. We use two simple encoding networks with differential connection structures as models of differential encoding in the two hemispheres based on a hypothesized generalization of neuroanatomical evidence from the auditory modality to the visual modality: The connection structure between columns is more distal in the language areas of the left hemisphere and more local in the homotopic regions in the right hemisphere. We show that both processing differences and differential frequency filtering can arise naturally in this neurocomputational model with neuroanatomically inspired differences in connection structures within the two model hemispheres, suggesting that hemispheric asymmetry in the processing of local and global features may be due to hemispheric asymmetry in connection structure rather than in frequency tuning.
左右大脑半球在处理局部和整体特征方面的不对称性，被认为源于两个半球在频率滤波方面的差异，但这种差异在神经生理学上并没有得到很好的支持。在这里，我们检验了这样一种假设，即这种不对称性发生在感觉水平之外的编码阶段，原因是每个半球内的解剖连接存在不对称。我们使用两个具有不同连接结构的简单编码网络作为模型，基于从听觉模式到视觉模式的神经解剖学证据的假设推广，来研究两个半球中不同编码的情况：在左侧语言区域中，柱之间的连接结构更加远程，而在右侧同源区域中，连接结构更加局部。我们表明，在这个具有神经解剖学启发的连接结构差异的神经计算模型中，既可以自然地产生处理差异和差分频率滤波，也可以产生处理局部和整体特征的半球性不对称，这表明局部和整体特征处理的半球性不对称可能是由于连接结构的半球性不对称，而不是频率调谐的不对称。
