Lateralization of semantic processing is shaped by exposure to specific mother tongues: The case of insight problem solving by bilingual and monolingual native Hebrew speakers

Solving insight problems is a complex task found to involve coarse semantic processing in the right hemisphere when tested in English. In Hebrew, the left hemisphere (LH) may be more active in this task, due to the inter-hemispheric interaction between semantic, phonological and orthographic processing. In two Hebrew insight problems experiments, we revealed a performance advantage in the LH, in contrast to the patterns previously observed in English. A third experiment, conducted in English with early Hebrew-English bilinguals, confirmed that the LH advantage found with Hebrew speakers does not depend on specific task requirements in Hebrew. We suggest that Hebrew speakers show redundancy between the hemispheres in coarse semantic processing in handling frequent lexical ambiguities stemming from the orthographic structure in Hebrew. We further suggest that inter-hemispheric interactions between linguistic and non-linguistic processes may determine the hemisphere in which coarse coding will take place. These findings highlight the possible effect of exposure to a specific mother tongue on the lateralization of processes in the brain, and carries possible theoretical and methodological implications for cross-language studies.