Effects of age-of-acquisition in Chinese reading : a mixed-effect modelling analysis

Abstract

The effect of age of acquisition (AoA) has been established as a determinant of lexical processing. However, the dynamics of its effects is still a matter of debate, from whether AoA has a single locus or multiple loci, to the level of processing its effects lie in. The current study explores the effects of AoA in Chinese in a lexical decision task and a character naming task by comparing the semantic transparency and phonological regularity of 2649 characters. The reaction time, accuracy and pupil dilation of 20 participants was analysed using mixed effects modelling. A general AoA effect was identified in all three measures. Behavioural results indicated a larger AoA effect in naming irregular characters and in recognizing opaque characters, which are evidential of both the arbitrary mapping hypothesis and the semantic hypothesis. Importantly, we found an interaction between AoA, semantic transparency and phonological regularity, where late-acquired, opaque and less regular words were responded to less accurately. This suggests that AoA has multiple loci and its effects arise from both semantic and phonological levels of representations. We also argue against a disconnect between the two hypotheses, as additional semantic activation was proved to be necessary during arbitrary mappings between orthography and phonology. Although pupillary response was not sensitive to the relationship of AoA with semantic transparency and phonological regularity, the presence of a main AoA effect in pupil dilation further supports the multiple-loci explanation of AoA effects and have implications that AoA effects exist beyond semantic and phonological stages of processing.