Staples Ryan, Graves William W
Department of Psychology, Rutgers University, 101 Warren St., Newark, NJ 07102.
Neurobiol Lang (Camb). 2020;1(4):381-401. doi: 10.1162/nol_a_00018. Epub 2020 Oct 1.
Determining how the cognitive components of reading - orthographic, phonological, and semantic representations - are instantiated in the brain has been a longstanding goal of psychology and human cognitive neuroscience. The two most prominent computational models of reading instantiate different cognitive processes, implying different neural processes. Artificial neural network (ANN) models of reading posit non-symbolic, distributed representations. The dual-route cascaded (DRC) model instead suggests two routes of processing, one representing symbolic rules of spelling-sound correspondence, the other representing orthographic and phonological lexicons. These models are not adjudicated by behavioral data and have never before been directly compared in terms of neural plausibility. We used representational similarity analysis to compare the predictions of these models to neural data from participants reading aloud. Both the ANN and DRC model representations corresponded with neural activity. However, ANN model representations correlated to more reading-relevant areas of cortex. When contributions from the DRC model were statistically controlled, partial correlations revealed that the ANN model accounted for significant variance in the neural data. The opposite analysis, examining the variance explained by the DRC model with contributions from the ANN model factored out, revealed no correspondence to neural activity. Our results suggest that ANNs trained using distributed representations provide a better correspondence between cognitive and neural coding. Additionally, this framework provides a principled approach for comparing computational models of cognitive function to gain insight into neural representations.
确定阅读的认知成分——正字法、语音和语义表征——是如何在大脑中实现的,一直是心理学和人类认知神经科学的长期目标。两种最著名的阅读计算模型实例化了不同的认知过程,这意味着不同的神经过程。阅读的人工神经网络(ANN)模型假定为非符号的分布式表征。而双通路级联(DRC)模型则提出了两条加工通路,一条表征拼写-发音对应的符号规则,另一条表征正字法和语音词典。这些模型没有通过行为数据来评判,并且以前从未在神经合理性方面进行过直接比较。我们使用表征相似性分析,将这些模型的预测与参与者大声朗读时的神经数据进行比较。ANN模型和DRC模型的表征都与神经活动相对应。然而,ANN模型的表征与更多与阅读相关的皮层区域相关。当对DRC模型的贡献进行统计控制时,偏相关分析表明ANN模型在神经数据中占显著方差。相反的分析,即剔除ANN模型的贡献来检验DRC模型所解释的方差,结果显示与神经活动没有对应关系。我们的结果表明,使用分布式表征训练的人工神经网络在认知编码和神经编码之间提供了更好的对应关系。此外,这个框架为比较认知功能的计算模型提供了一种有原则的方法,以深入了解神经表征。