How we turn languages 'on' and 'off'

Washington D.C. [USA] Sep 11 (ANI): The distinct computations that occur when we switch between different languages, is a new finding that provides insights into the nature of bilingualism.
Lead author of the study, Esti Blanco-Elorrieta, said, "A remarkable feature of multilingual individuals is their ability to quickly and accurately switch back and forth between their different languages."
Senior author Liina Pylkkanen, said, "Specifically, this research unveils for the first time that while disengaging from one language requires some cognitive effort, activating a new language comes relatively cost-free from a neurobiological standpoint."
Previous research has linked language switching with increased activity in areas associated with cognitive control. However, it was unknown whether it is disengaging from the previous language or engaging in a new language that drives this activity.
This is mainly because these two processes happen simultaneously when those who speak two languages switch from one to the other (i.e., when participants switch from speaking Spanish to speaking English, turning Spanish "off" and turning English "on" happen at the same time).
The scientists observed bilingual speakers who viewed the same pictures and named them with semantically identical expressions. In order to gauge the study subjects' brain activity during this experiment, the researchers deployed magnetoencephalography (MEG), a technique that maps neural activity by recording magnetic fields generated by the electrical currents produced by our brain.
The results showed that when bilinguals fluent in American Sign Language (ASL) and English switched languages, turning a language "off" led to increased activity in cognitive control areas while turning a language "on" was no different than not switching.
The researchers also found that for such speakers, producing two words simultaneously (one sign and one spoken word) was not necessarily more cognitively costly than producing only one.
"In all, these results suggest that the burden of language-switching lies in disengagement from the previous language as opposed to engaging a new language," says Blanco-Elorrieta.
The full findings are present in the journal- Proceedings of the National Academy of Sciences. (ANI)