Poster D23, Friday, August 17, 4:45 – 6:30 pm, Room 2000AB
Examining plasticity of the reading network: insights from deaf readers of Chinese
Junfei Liu1,2,3,4, Tae Twomey1,2, Mengke Wu3,4, Yiming Yang3,4, Mairead MacSweeney1,2;1Institute of Cognitive Neuroscience, University College London, 2Deafness, Cognition and Language Research Centre, University College London, 3Jiangsu Key Laboratory of Language and Cognitive Neuroscience, Jiangsu Normal University, 4School of Linguistic Sciences and Arts, Jiangsu Normal University
The meaning of written words can be accessed directly from orthography or indirectly via phonology. These two routes work together during reading but the weights between them can be modulated by many factors such as the experimental task and the type of script used to represent spoken language. Spoken Chinese is represented using a logographic script. Unlike alphabetic scripts, Chinese orthography generally maps more closely to meaning than to sound. The only published fMRI study of deaf readers of Chinese showed greater activation in right inferior frontal gyrus (IFG), middle frontal gyrus (MFG), supramarginal gyrus (SMG) and angular gyrus (AG) during both rhyming and semantic tasks in deaf than hearing participants (Li et al., 2014). However, deaf and hearing people typically differ in their reading ability. Therefore, it is possible that the difference observed between deaf and hearing readers of Chinese are influenced by the difference in reading levels of the two groups. Using fMRI, we examined the brain network supporting reading Chinese characters in deaf and hearing participants who were matched on reading level. Fifteen deaf and 15 hearing adults were asked to make rhyming and semantic judgements on two simultaneously presented Chinese Characters. A visual similarity judgment task was used as the control task. For both the reaction time (RT) and accuracy data, the main effect of task was significant. However, the main effect of group and the interaction were not significant. The RTs were significantly longer and the accuracies were significantly lower for the rhyming task than the semantic task. RTs were included as a covariate in the whole brain analyses. The fMRI results showed that the rhyming task generated more activation than the semantic task in bilateral precentral gyrus and SMG, left superior parietal lobule, insula and SFG (p < .05, FWE corrected). For the semantic task relative to the rhyming task, significant activation was found in bilateral AG (p < .05, FWE corrected). The main effect of group as well as the interaction was not significant at p < .05 FWE corrected nor even at p < .001 uncorrected. It should be noted however, that, in line with previous literature, there was greater activation in deaf than hearing participants in superior temporal cortices bilaterally when fixation was used as a baseline. The present study shows that deaf and hearing readers of Chinese, who are matched on reading ability, recruit a similar reading network despite the very different auditory experience. This may be the result of the characteristics of the Chinese orthography and/or the visual and semantic approach used to teach Chinese children how to read. The findings suggest that the effect of deafness on the reading network may not be universal.
Topic Area: Writing and Spelling