Language Differences in the Brain Network for Reading in Naturalistic Story Reading and Lexical Decision

Abstract

Differences in how writing systems represent language raise important questions about whether there could be a universal functional architecture for reading across languages. In order to study potential language differences in the neural networks that support reading skill, we collected fMRI data from readers of alphabetic (English) and morpho-syllabic (Chinese) writing systems during two reading tasks. In one, participants read short stories under conditions that approximate natural reading, and in the other, participants decided whether individual stimuli were real words or not. Prior work comparing these two writing systems has overwhelmingly used meta-linguistic tasks, generally supporting the conclusion that the reading system is organized differently for skilled readers of Chinese and English. We observed that language differences in the reading network were greatly dependent on task. In lexical decision, a pattern consistent with prior research was observed in which the Middle Frontal Gyrus (MFG) and right Fusiform Gyrus (rFFG) were more active for Chinese than for English, whereas the posterior temporal sulcus was more active for English than for Chinese. We found a very different pattern of language effects in a naturalistic reading paradigm, during which significant differences were only observed in visual regions not typically considered specific to the reading network, and the middle temporal gyrus, which is thought to be important for direct mapping of orthography to semantics. Indeed, in areas that are often discussed as supporting distinct cognitive or linguistic functions between the two languages, we observed interaction. Specifically, language differences were most pronounced in MFG and rFFG during the lexical decision task, whereas no language differences were observed in these areas during silent reading of text for comprehension.

Cortical regions supporting reading comprehension skill for single words and discourse

“…These findings are consistent with studies directly contrasting single words and passages (Wang et al, 2015). This suggests that these regions support single-word processing specifically when compared to passage comprehension.…”

“…Participants completed a modified version of the story task described in Wang and colleagues (2015). In the scanner, participants passively read or listened to four stories by Hans Christian Andersen across four scan runs.…”

“…To complement our passage task, we developed a task-free single word processing task. Previous reports note that comparing word- and passage-level processing across studies presents confounds due to differing task demands (Wang et al, 2015). Thus, our single word processing task is passive and task-free to allow for the most valid comparison of processing level between our passage and word processing tasks.…”

Underlying Skills of Oral and Silent Reading Fluency in Chinese: Perspective of Visual Rapid Processing

“…This reveals the relationship between visuospatial attention and Chinese reading fluency, to some extent. Moreover, Wang et al (2015) have found that silent reading of Chinese sentences would induce activation in the middle temporal gyrus which is thought to be important for the direct mapping of orthography to semantics. Based on this finding, it can be proposed that Chinese readers’ visual attention span may have an impact on the parallel processing of multiple orthographic units of Chinese characters which in turn may affect the efficiency of their sentence comprehension ability during the silent reading task.…”

“…Based on this model, global processing typically requires a larger visual attention span than analytic processing (Bosse et al, 2007). Wang et al (2015) has showed that silent reading mainly relies on the global orthographic-to-semantic mapping. In contrast, oral reading fluency has been reported to be involved in the orthographic-to-phonological mapping.…”