Brain Circuit for Cognitive Control Is Shared by Task and Language Switching

TLDR

Controlling multiple languages during speech production is thought to involve mechanisms shared with domain‑general cognitive control, and neuroimaging has suggested some neural overlap, though evidence has been indirect. The study aimed to provide direct evidence of this overlap by comparing language and nonverbal switching within the same participants under closely matched task conditions. Using fMRI, the authors examined switch‑specific brain activation during a linguistic switching task and a matched nonlinguistic switching task in early, highly proficient Spanish‑Basque bilinguals. The results demonstrate that highly similar brain circuits underlie both language control and domain‑general cognitive control in these bilinguals.

Abstract

Controlling multiple languages during speech production is believed to rely on functional mechanisms that are (at least partly) shared with domain-general cognitive control in early, highly proficient bilinguals. Recent neuroimaging results have indeed suggested a certain degree of neural overlap between language control and nonverbal cognitive control in bilinguals. However, this evidence is only indirect. Direct evidence for neural overlap between language control and nonverbal cognitive control can only be provided if two prerequisites are met: Language control and nonverbal cognitive control should be compared within the same participants, and the task requirements of both conditions should be closely matched. To provide such direct evidence for the first time, we used fMRI to examine the overlap in brain activation between switch-specific activity in a linguistic switching task and a closely matched nonlinguistic switching task, within participants, in early, highly proficient Spanish-Basque bilinguals. The current findings provide direct evidence that, in these bilinguals, highly similar brain circuits are involved in language control and domain-general cognitive control.