The age of acquisition effect of L2 word is dependent on or independent of L1 word age of acquisition? Evidences from learning of L2 pseudowords

The study explored the origin of the age of acquisition (AoA) effect in second language (L2) using ERPs technique. We simulated L2 AoA by manipulating the order at which English pseudowords entered into training. Chinese-English bilinguals (mean age 22.04, range 18–28) learned English pseudowords matched with Chinese (L1) words, investigating the order of acquisition (OoA) effect of English pseudowords and its relationship with the matched L1 words’ AoA. OoA effects were observed in lexical decision, naming and semantic judgment tasks on N170, P200 and N400. Furthermore, OoA effects were modulated by L1 AoA in the semantic judgment task. These results suggested that OoA effects were independent at orthographic and phonological levels but modulated by L1 AoA at the semantic level. The interpretation of L2 AoA effects requires not only the integration of Semantic and Arbitrary Mapping Hypotheses, as well as consideration of the representation and activation characteristics of L2 words.