Age-of-acquisition effects in lexical decision and naming: A partly semantic and partly arbitrary mapping account

Word age-of-acquisition (AoA) is a strong determinant of lexical processing. However, whether AoA has a single or multiple-loci remains a debate. Behavioural and pupillary responses investigating AoA, semantic transparency and phonological regularity of 2649 Chinese characters were examined in lexical decision and naming tasks using mixed-effects modelling. Characters learned early elicited larger pupil dilations and were more readily and accurately recognized and named than late acquired ones. Furthermore, larger AoA effects were found in naming irregular characters and recognizing semantically opaque characters, supporting both the arbitrary mapping and semantic hypotheses. Importantly, late-acquired semantically opaque irregular characters were responded to less accurately, suggesting multiple AoA loci at both semantic and phonological levels of representation as semantic activation facilitated transparent irregular characters. Lastly, the pupillary AoA effect and absence of phonological or semantic interactions further supports a multiple-loci account whereby AoA effects also exist at the early visual-orthographic stages of lexical processing. Copyright © 2020 The 61st Annual Meeting of the Psychonomic Society.