Search Abstracts | Symposia | Slide Sessions | Poster Sessions
Cortico-Cerebellar Synergistic Mechanisms in Chinese Poor Readers: A Dynamic Processing Perspective
Poster Session D, Thursday, October 1, 4:30 - 6:30 pm, Wangari Maathai
Hehui Li1, Ke Hu1, Guotao Chen1, Wuhai Tao1, Yu Dong2; 1School of Psychology, Shenzhen University, Shenzhen, China, 2Cognitive Science and Allied Health School, Beijing Language and Culture University, Beijing, China
Developmental dyslexia is a common neurodevelopmental disorder marked by impairments in reading accuracy and fluency. Reading ability is continuously distributed in the general population, with dyslexia representing the lower end of this spectrum. However, how cortical and cerebellar systems jointly support reading-related learning, and whether their cooperation differs across individuals with varying reading ability, remains unclear in logographic systems such as Chinese, where successful reading depends heavily on the formation of stable orthography–semantics mappings. From a continuum perspective, we combined a pseudo-character form–meaning association learning paradigm with functional magnetic resonance imaging (fMRI), a dynamic causal model and a hierarchical drift diffusion model (HDDM) to examine how cortical and cerebellar systems cooperate during learning, and whether such cooperation differs as a function of reading ability. We selected good readers (n = 37) and poor readers (n = 35) from a cohort of 334 university students based on standardized reading assessments. Across repeated learning blocks, participants gradually associated novel Chinese-like characters with specific meanings, allowing us to track learning-related neural dynamics. Behaviorally, both groups showed robust learning effects, with accuracy rising from 50% to 97%. Three main findings stood out. First, the left fusiform gyrus (LFG) showed the strongest activation throughout learning, whereas the right cerebellar language regions (lobules VI/VIII) exhibited relatively weaker activation, but significantly stronger functional connectivity with the left inferior parietal lobule (IPL) than with the LFG. This suggests that the cerebellum may contribute to Chinese character learning primarily through coordination with higher-order semantic integration regions. Second, dynamic causal modeling revealed an inhibitory effective connection from the LFG to the left IPL during early learning, consistent with a gating mechanism when form–meaning associations are still unstable. Third, although no reliable group differences were found in regional activation or connectivity, fMRI-informed HDDM analyses showed stronger neural activity–drift rate coupling in poor readers within the LFG, left IPL, and right cerebellar lobule VIII. Moreover, the left IPL showed a joint modulation by group and learning stage, indicating sustained compensatory involvement in individuals with lower reading ability. Together, these findings suggest that reading ability differences are reflected less in regional recruitment than in how neural signals dynamically shape evidence accumulation during learning. In particular, individuals with lower reading ability appear to rely more strongly on trial-by-trial neural activity, rather than on a more automatized learning pathway. These results provide new evidence for understanding the cortico–cerebellar mechanisms of Chinese reading difficulty from a continuum perspective.
Topic Areas: Reading, Writing and Spelling