Age of acquisition in naming Japanese words

The effect of age of acquisition (AoA) on word naming in Japanese was examined. Half of the participants had words presented in Kanji, and for the other half the same words were presented in Kana. There was a main effect of script with words being read aloud faster when presented in their Kana compared to Kanji transcription, and a main effect of AoA with faster naming times to earlier acquired stimuli. The interaction between AoA and type of script was also significant, with the AoA effect being larger when naming words presented in Kanji compared to naming the same words when presented in Kana. These results are consistent with the hypothesis that the size of the AoA effect is influenced by the nature of mapping between orthography and phonology.