The Distinct Roles of Dorsal and Ventral Visual Systems in Naming of Chinese Characters

• Published in: Neuroscience Vol. 390; pp. 256 - 264
• Main Authors: Zhou, Wei, Xia, Zhichao, Georgiou, George K., Shu, Hua
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 15.10.2018
• Subjects: Adult; Brain - physiology; Brain Mapping; character reading; Chinese; dorsal visual regions; effective connectivity; Female; Humans; Magnetic Resonance Imaging; Male; Neural Pathways - physiology; Pattern Recognition, Visual - physiology; rapid automatized naming; Reading; ventral visual regions; Visual Cortex - physiology; Visual Pathways - physiology; Young Adult; dorsal visual regions; GCA; character reading; medFC; rapid automatized naming; IPS; MFG; fMRI; ventral visual regions; ECs; VWFA; effective connectivity; Chinese; IOC; RAN; preFC
• ISSN: 0306-4522; 1873-7544; 1873-7544
• DOI: 10.1016/j.neuroscience.2018.08.024

•Subjects read character and cross-matrices in the fMRI scanner.•Character reading elicited higher activation in L.MFG, L.STG and L.FG than cross scanning.•Top-down and bottom-up connections among dorsal and ventral regions were observed in character reading.•Only top-down connections were found in cross scanning.•The dorsal and ventral connections in character reading were associated with prosaccades and naming respectively. We aimed to investigate the role of dorsal and ventral visual systems in rapid naming of simple Chinese characters. Twenty college students (10 female; Mage = 22.5 years) were required to covertly read a character- and a cross-matrix during an fMRI experiment. A basic prosaccade and a prosaccade-naming task were also performed to confirm the functional significance of the findings. The results of whole brain analysis showed that both dorsal and ventral visual systems were activated in the character-matrix reading. The cross-matrix scanning elicited weaker activation in the left middle frontal gyrus, superior temporal gyrus, and ventral occipitotemporal cortex. Next, whereas both top-down and bottom-up effective connectivities (ECs) were found between these two systems in the character-matrix reading, only top-down ECs were observed in the cross-matrix scanning. Moreover, in the character-matrix reading, we found a negative correlation between the reaction time of naming in the prosaccade-naming task and the EC strength from visual word form area to superior temporal gyrus and a positive correlation between the reaction time in the basic prosaccade task and the EC strength from middle frontal gyrus to intraparietal sulcus. The cross-matrix scanning did not show any brain-behavior relationship. These results suggest that while the dorsal visual system is mainly engaged in eye-movement control, the ventral system is associated more with orthographic processing and orthography-phonology mapping.