The Network of Brodmann's Area 22 in Lexico-semantic Processing: A Pooling-data Connectivity Study

Background and Objective: Modern neuroimaging has demonstrated that cognitive functions are based in networks of interconnected modules. The purpose of this paper was to analyze the connectivity of Brodmann's area (BA) 22 in lexico-semantic tasks. Methods: A connectivity fMRI co-activation study was performed by pooling data of lexico-semantic tasks in which BA22 (core of Wernicke's area) was reported. 283 subjects reported in 21 experiments were analyzed. Analysis of Likelihood Estimates of pooled data was utilized to generate the connectivity map; thresholds at p < 0.01 were corrected for multiple comparisons with false discovery rate. Resulting images were co-registered into MNI standard space. Results: A network consisting of 13 clusters of activation was obtained. Main clusters were located in the left posterior temporal and left inferior frontal gyrus; in addition to these canonical areas, left insula, pre-supplementary motor area, left BA37, primary auditory areas and left occipital lobe were also involved. Conclusions: BA22-related networks involved in lexico-semantics processing were demonstrated utilizing a pooling-data connectivity study. Significance, interpretation and limitations of the results are discussed.