Klichowski Michal, Króliczak Gregory
Faculty of Educational Studies, Adam Mickiewicz University in Poznan, Poznan, Poland.
Action and Cognition Laboratory, Institute of Psychology, Faculty of Social Sciences, Adam Mickiewicz University in Poznan, Poznan, Poland.
Neuropsychologia. 2017 Jun;100:93-109. doi: 10.1016/j.neuropsychologia.2017.04.019. Epub 2017 Apr 14.
Potential links between language and numbers and the laterality of symbolic number representations in the brain are still debated. Furthermore, reports on bilingual individuals indicate that the language-number interrelationships might be quite complex. Therefore, we carried out a visual half-field (VHF) and dichotic listening (DL) study with action words and different forms of symbolic numbers used as stimuli to test the laterality of word and number processing in single-, dual-language and mixed -task and language- contexts. Experiment 1 (VHF) showed a significant right visual field/left hemispheric advantage in response accuracy for action word, as compared to any form of symbolic number processing. Experiment 2 (DL) revealed a substantially reversed effect - a significant right ear/left hemisphere advantage for arithmetic operations as compared to action word processing, and in response times in single- and dual-language contexts for number vs. action words. All these effects were language independent. Notably, for within-task response accuracy compared across modalities significant differences were found in all studied contexts. Thus, our results go counter to findings showing that action-relevant concepts and words, as well as number words are represented/processed primarily in the left hemisphere. Instead, we found that in the auditory context, following substantial engagement of working memory (here: by arithmetic operations), there is a subsequent functional reorganization of processing single stimuli, whether verbs or numbers. This reorganization - their weakened laterality - at least for response accuracy is not exclusive to processing of numbers, but the number of items to be processed. For response times, except for unpredictable tasks in mixed contexts, the "number problem" is more apparent. These outcomes are highly relevant to difficulties that simultaneous translators encounter when dealing with lengthy auditory material in which single items such as number words (and possibly other types of key words) need to be emphasized. Our results may also shed a new light on the "mathematical savant problem".
语言与数字之间的潜在联系以及大脑中符号数字表征的偏侧性仍存在争议。此外，关于双语者的报告表明，语言与数字的相互关系可能相当复杂。因此，我们进行了一项视觉半视野（VHF）和双耳分听（DL）研究，使用动作词和不同形式的符号数字作为刺激，以测试单语、双语和混合任务及语言情境中单词和数字处理的偏侧性。实验1（VHF）显示，与任何形式的符号数字处理相比，动作词的反应准确性在右视野/左半球具有显著优势。实验2（DL）揭示了一种明显相反的效应——与动作词处理相比，算术运算在右耳/左半球具有显著优势，并且在单语和双语情境中数字与动作词的反应时间上也存在优势。所有这些效应都与语言无关。值得注意的是，对于跨模态的任务内反应准确性进行比较时，在所有研究情境中都发现了显著差异。因此，我们的结果与那些表明与动作相关的概念和单词以及数字单词主要在左半球表征/处理的研究结果相反。相反，我们发现，在听觉情境中，在工作记忆大量参与（此处：通过算术运算）之后，无论是动词还是数字，处理单个刺激会有随后的功能重组。这种重组——它们减弱的偏侧性——至少对于反应准确性而言，并非数字处理所独有，而是与要处理的项目数量有关。对于反应时间，除了混合情境中不可预测的任务外，“数字问题”更为明显。这些结果与同声传译员在处理冗长的听觉材料时遇到的困难高度相关，在这些材料中，诸如数字单词（以及可能的其他类型关键词）等单个项目需要被强调。我们的结果也可能为“白痴学者问题”带来新的启示。
