Optimizing lexical learning by manipulating phonological training

In this thesis, I examine the impact of manipulating phonological training environments on learning novel words in adulthood. Adults who learn non-native phonological categories are thought to utilize two main types of strategies. A reflective strategy involves developing explicit rules for categorizing sounds, whereas a reflexive strategy entails implicitly mapping sounds onto representations. Successful learning has been associated with a transition from a reflective to a reflexive strategy. This study examined the extent to which successful phonological category learning can lead to the enhanced acquisition of novel lexical items based on the same phonological category structure. Monolingual English speakers (N=40) learned to categorize Mandarin tones in one of four training regimens. Participants in a Reflect→Reflex condition were initially presented with a training environment designed to enhance reflective learning and then with an environment designed to enhance reflexive learning. Participants in a Reflex→Reflect condition were presented with the two environments in a reversed order. Training environments in two control conditions exclusively targeted either reflective or reflexive learning. Following phonological training, participants were trained to identify novel pseudo-Mandarin lexical items using a sound-to-meaning training paradigm across three days. Participants in the Reflect→Reflex condition outperformed all conditions on the lexical task, despite equivalent performance in the earlier phonological categorization task. Results support initially targeting reflective and later targeting reflexive systems during speech category learning. The findings suggest that reducing challenges in phonological categorization via optimized training approaches may help bootstrap novel word learning.