Functional Anatomy of Recognition of Chinese Multi-Character Words: Convergent Evidence from Effects of Transposable Nonwords, Lexicality, and Word Frequency.

Nan Lin,Kevin Paterson,Ying Zhao,Mingxia Zhang,Xi Yu

doi:10.1371/journal.pone.0149583

Abstract

This fMRI study aimed to identify the neural mechanisms underlying the recognition of Chinese multi-character words by partialling out the confounding effect of reaction time (RT). For this purpose, a special type of nonword—transposable nonword—was created by reversing the character orders of real words. These nonwords were included in a lexical decision task along with regular (non-transposable) nonwords and real words. Through conjunction analysis on the contrasts of transposable nonwords versus regular nonwords and words versus regular nonwords, the confounding effect of RT was eliminated, and the regions involved in word recognition were reliably identified. The word-frequency effect was also examined in emerged regions to further assess their functional roles in word processing. Results showed significant conjunctional effect and positive word-frequency effect in the bilateral inferior parietal lobules and posterior cingulate cortex, whereas only conjunctional effect was found in the anterior cingulate cortex. The roles of these brain regions in recognition of Chinese multi-character words were discussed.

Highlights

Word recognition is a basic component of reading and has been studied extensively by different methods
The results showed that the reaction time (RT) in the lexical decision task and reading times on the target words were shorter in the transposable-nonword condition than in the regular-nonword condition, indicating that the transposable nonwords can prime their base words from an early stage of word recognition
Neural mechanisms underlying recognition of Chinese multi-character words were investigated by examining the brain activation evoked by Chinese multi-character words, transposable nonwords, and regular nonwords

Summary

Introduction

Word recognition is a basic component of reading and has been studied extensively by different methods. Neuroimaging studies have deepened our understanding of word recognition by providing insights into its functional anatomy [1,2,3]. The most direct way to explore brain structures associated with word recognition is to compare brain activation evoked by words with that evoked by nonwords. The difference in brain activation elicited by the word and nonword conditions, which is often referred to as the lexicality effect, has been observed in extensive brain regions, indicating that skilful word recognition requires/evokes the interplay of various neural networks and processes [1, 2].

Methods

Results

Conclusion