There is considerable evidence showing that age ofacquisition (AoA) is an important factor influencing lexicalprocessing. Early-learned words tend to be processed morequickly compared to later-learned words. The effect could bedue to the gradual reduction in plasticity as more words arelearned. Alternatively, it could originate from differenceswithin semantic representations. We implemented the trianglemodel of reading including orthographic, phonological andsemantic processing layers, and trained it according toexperience of a language learner to explore the AoA effects inboth naming and lexical decision. Regression analyses on themodel’s performance showed that AoA was a reliablepredictor of naming and lexical decision performance, and theeffect size was larger for lexical decision than for naming.The modelling results demonstrate that AoA operatesdifferentially on concrete and abstract words, indicating thatboth the mapping and the representation accounts of AoAwere contributing to the model’s performance.

Learning to read has a substantial effect on the representationsof spoken and meaning forms of words. In this paper weassess literacy effects beyond representational changes,focusing on adaptations to the architecture of the readingsystem that maps between these representations. We present aconnectionist model of reading that predicted distinctprocessing of pre- and post-literacy acquired words. Forreading for meaning, words learned prior to literacy wereprocessed more indirectly via phonological representations,whereas for post-literacy acquired words, processing wasmore direct along the orthography to semantics pathway. Thismore computationally intensive route was prioritised becauseindirect phonology to semantics mappings were unavailable.Such an effect was less apparent for naming, because learningdirect orthography to phonology mappings is lesscomputationally intensive. These results were confirmed in ananalysis of naming and lexical decision behavioural data. Theeffect of literacy onset remains an observable artefact in adultreading.