Centre for Cognitive Neuroscience, Universität Salzburg, Salzburg, Austria.
Allgemeine und Neurokognitive Psychologie, Freie Universität Berlin, Berlin, Germany.
Sci Rep. 2019 Mar 14;9(1):4506. doi: 10.1038/s41598-019-41011-9.
Neurocognitive studies of visual word recognition have provided information about brain activity correlated with orthographic processing. Some of these studies related the orthographic neighborhood density of letter strings to the amount of hypothetical global lexical activity (GLA) in the brain as simulated by computational models of word recognition. To further investigate this issue, we used GLA of words and nonwords from the multiple read-out model of visual word recognition (MROM) and related this activity to neural correlates of orthographic processing in the brain by using functional magnetic resonance imaging (fMRI). Words and nonwords elicited linear effects in the cortex with increasing BOLD responses for decreasing values of GLA. In addition, words showed increasing linear BOLD responses for increasing GLA values in subcortical regions comprising the hippocampus, globus pallidus and caudate nucleus. We propose that these regions are involved in the matching of orthographic input onto representations in long-term memory. The results speak to a potential involvement of the basal ganglia in visual word recognition with globus pallidus and caudate nucleus activity potentially reflecting maintenance of orthographic input in working memory supporting the matching of the input onto stored representations by selection of appropriate lexical candidates and the inhibition of orthographically similar but non-matching candidates.
神经认知研究对视觉单词识别进行了研究，为大脑活动与正字法处理的相关性提供了信息。其中一些研究将字母串的正字法邻域密度与大脑中假设的全局词汇活动（GLA）的数量相关联，这些活动是通过单词识别的计算模型模拟的。为了进一步研究这个问题，我们使用了视觉单词识别的多重读出模型（MROM）中的单词和非单词的 GLA，并通过使用功能磁共振成像（fMRI）将这种活动与大脑中正字法处理的神经相关物相关联。单词和非单词在皮层中引起线性效应，随着 GLA 值的降低，BOLD 反应增加。此外，在包括海马体、苍白球和尾状核在内的皮质下区域，单词的 GLA 值增加，线性 BOLD 反应也随之增加。我们提出，这些区域参与了将正字法输入与长期记忆中的表示相匹配。研究结果表明，基底神经节可能参与了视觉单词识别，苍白球和尾状核的活动可能反映了在工作记忆中维持正字法输入，以支持通过选择适当的词汇候选词和抑制具有相似但不匹配的正字法候选词来将输入与存储的表示相匹配。
