Individual differences in hemispheric lateralization of language processing

INDIVIDUAL DIFFERENCES AND BRAIN LATERALITY IN LANGUAGEPROCESSINGbySARAH A. VAN DYKEAugust 2011Advisor: R. Douglas WhitmanMajor: Psychology (clinical)Degree: Doctor of PhilosophyConclusions in the literature regarding the relationship between a lateralized biasin the processing of information and individual differences (e.g., biological sex, genderidentity, ability, personality) are inconsistent. Two different measures of laterality werecompared: dichotic listening and lateralized semantic priming and their relation to sex,verbal and visual-spatial ability, gender identity, and personality.Eighty-nine adults (44 women, 45 men) were administered the WechslerAbbreviated Scale of Intelligence, Bem Sex Role Inventory, and Big Five Inventory inaddition to a dichotic listening task and a lateralized semantic priming task that compared ipsilateral and contralateral priming in order to determine the role ofinterhemispheric transfer. Two stimulus onset asynchronies (SOA; 50 ms and 400 ms) and two levels of association strength (high and neutral) between the prime and thetarget words were used in the priming task. Ipsilateral prime-target reaction times were faster than contralateral prime-target presentations, while contralateral presentations resulted in greater semantic priming,suggesting that the time required for interhemispheric transfer allows for greater