Study appeared in The Psychonomic Society website
A recent article was written in The Psychonomic Society about lying in your native and non-native language, citing Duñabeitia And Costa's recently publication.
This study used pupil dilation as a measure of emotional response and cognitive load, and found that pupil dilation was greater when participants spoke in their foreign language than when they spoke their native language. Pupil dilation was also greater when participants were lying than when they were being truthful.
Interestingly, the magnitude of the effect of lying was comparable in both their native an non-native languages. This is intriguing because it suggests that the participants were unable to fully distance themselves from the lie in a non-native langauge.
To read the article on The Psychonomic Society, click here.
To read the original study by Duñabeitia and Costa, click here.