The study involving Glasgow and Edinburgh universities will require its test subjects to speak Gaelic exclusively for about 40 days.
The research aims to add new scientific evidence to suggestions that people who are bilingual have enhanced problem-solving skills and flexible thinking.
The study will include MRI scans to help detect changes in brain functions.
Scientists from Scotland, Belgium and Germany leading the research said the experiments would be entirely non-invasive.
They will be carried out at University of Glasgow's Centre for Cognitive Neuroimaging, with approval of the College of Science and Engineering's ethics committee.
Dr Meike Ramon, of the University of Glasgow and Belgium's Universite catholique de Louvain, said brain functions changed when people performed specific tasks.
She said it should be possible to identify changes before and after someone has spoken Gaelic over a long period.
Research published in August suggested bilingual children outperform children who speak only one language in problem-solving skills and creative thinking.
Researchers set lingual, arithmetical and physical tasks for 121 children, aged about nine, in Scotland and Sardinia, Italy.
They found that the 62 bilingual children were "significantly more successful in the tasks set for them".
The study was published in the International Journal of Bilingualism.
The Glasgow-based children spoke English and Gaelic, or English only, while the Sardinian cohort spoke either Italian only, or Italian and Sardinian.
They were asked to reproduce patterns of coloured blocks, to repeat orally a series of numbers, to give clear definitions of words and to resolve mentally a set of arithmetic problems.
The tasks were all set in English or Italian.
Researchers found that the bilingual children were "significantly more successful in the tasks set for them".
Last month, research published by the University of the Highlands and Islands suggested that generations of families that speak Gaelic use the language in different ways.
Gaelic dominates the conversations of family members aged between 53 and 71.
Second and third generations, family aged 16-37 and three to seven, mostly use English.
But the research also found adults spoke Gaelic when talking to children, who in turn would reply in the language.
BBC News. 2012. “New study of how Gaelic affects brain functions”. BBC News. Posted: December 20, 2012. Available online: http://www.bbc.co.uk/news/uk-scotland-highlands-islands-20795997