Neural substrates of Chinese lexical production: The role of domain-general cognitive functions

Verbal fluency test, a type of word generation task, is a commonly used neuropsychological assessment. Among the healthy population, it has been used to assess verbal ability, but also executive functions. In the clinical field, verbal fluency has been used to support the diagnoses of a number of neuropsychological disorders. However, existing evidence do not allow for clear conclusions on whether such nonlinguistic uses of verbal fluency test are justified. The present study therefore investigated the involvement of domain-general cognitive functions in word production using functional magnetic resonance imaging, assessing verbal fluency, response inhibition, and working memory updating brain activations in the same set of participants. Results showed that response inhibition and working memory updating do play a role in verbal-fluency-type word production tasks, although language-specific regions are also required. Furthermore, domain-general and language-specific areas are closely neighboring subregions within the same broad brain regions. Additionally, a neural network for Chinese lexical production was observed, which corroborate neural bases for production in alphabetic languages, indicating that there is a core network for lexical production, regardless of language, production mode, or cue stimulus type, with other additional areas involved under some production conditions. Given that most previous research only investigated alphabetic languages, these results help gain a better understanding of language production mechanisms across languages.