Neuronal substrates for language processing and word priming

The authors of this chapter studied behavioral performance and brain activities associated with word priming using a Japanese Word Stem Completion (WSC) task. They compared the results of this task with the results of a Korean character cognitive task. Their results showed facilitatory effects on subject performance. The percentage of correct answers in the non-priming (P/N) word condition was 94%, whereas the priming (P/Y) condition yielded 100% correct answers. The average reaction time during the P/N word condition was 1501 ms, whereas it was 978 ms and 3106 ms for the P/N non-word and word P/Y word conditions, respectively. In the fMRI experiment, the same tasks were performed using a block-design experimental paradigm without any overt response from the MRI scanner. As seen in the fMRI results, the bilateral middle and inferior frontal gyrus were active with a right hemispheric prevalence. In addition, the superior and inferior parietal gyrus and the supplementary motor area were activated. The prefrontal-parietal network observed in this study is consistent with the areas that were activated during an English word stem task. These results suggest that the facilitatory effects observed in the WSC test were successful for implicit memory retrieval.