Lexical decision and semantic categorization: age of acquisition effects with students and elderly participants

Age of acquisition (AoA) effects have often been found in a large variety of tasks involving word processing. One of the ongoing discussions remains the confounding of AoA effects with word frequency (e.g. Morrison & Ellis, 1995). In this study we removed possible frequency confounds by comparing AoA and word familiarity differences with young and older participants. A lexical decision experiment was conducted to test if reaction time (RT) differences of both age groups might be explained by differences in AoA of the words. Previous research (Brysbaert, Van Wijnendaele, & De Deyne, 2000) has shown that AoA effects might also have a semantic origin, apart from proposed origins at the word output or word form access level. To further test this hypothesis we adapted the lexical decision procedure to become a semantic categorization task.