Differential bilingual laterality: mythical monster found in Wales.

Paradis (1992) likens studies of bilingual laterality to reported sightings of the Loch Ness Monster, in that although some studies claim differential laterality much conflicting research evidence does not-and like the mythical Scottish monster, what reason have we to suspect that any such phenomenon might exist? This study reexamines differential bilingual laterality using four groups of English-Welsh bilinguals which differ in their age of acquisition and in their environment of acquisition. Using a split visual field paradigm we present evidence which, supports the notion of greater right hemisphere processing in a later learned language. Our findings also suggest the pattern of lateralization in bilinguals is strongly affected by the specific language environment during development such that the shift toward greater right hemisphere involvement for the later learned language will be more pronounced in individuals which are brought up in areas where that language is not regularly heard.