Age of acquisition and the cumulative-frequency hypothesis: A review of the literature and a new multi-task investigation

Early-acquired words are processed faster than late-acquired words. This is a well-accepted effect within the word recognition literature. Different explanations have been proposed, either localizing the effect of age of acquisition (AoA) in a particular substage of word processing or seeing it as the result of the way in which information is stored and accessed in the brain in general. The cumulative-frequency hypothesis is an example of the latter type of explanation: It states that the total number of times a system has come across a particular stimulus will determine the speed with which the stimulus can be recognized. The present multi-task investigation provides a critical test of the different explanations. Results show that in a variety of word processing tasks the effects of frequency and AoA are highly correlated, and that the impact of AoA is consistently higher than would be expected on the basis of the cumulative-frequency hypothesis. The findings are interpreted as evidence for recent demonstrations of a loss of plasticity in neural networks due to training and/or for mathematical models that describe the growth of the lexico-semantic network as the attachment of new nodes to existing nodes

Age of acquisition effects in picture naming: Evidence for a lexical-semantic competition hypothesis

In many tasks the effects of frequency and age of acquisition (AoA) on reaction latencies are similar in size. However, in picture naming the AoA-effect is often significantly larger than expected on the basis of the frequency-effect. Previous explanations of this frequency-independent AoA-effect have attributed it to the organisation of the semantic system or to the way phonological word forms are stored in the mental lexicon. Using a semantic blocking paradigm, we show that semantic context effects on naming latencies are more pronounced for late-acquired than for early-acquired words. This interaction between AoA and naming context is likely to arise during lexical-semantic encoding, which we put forward as the locus for the frequency-independent AoA effect