First language lexical attrition remains a difficult phenomenon to study empirically, due to its long-term and dynamic effects. Based on observations from existing case studies, we propose a connectionist model to simulate the effects of first language lexical attrition. The model exhibits a plausible time-course for first language lexical comprehension, highlights the independence of productive and receptive attrition trajectories, and predicts an age of onset effect for early cases of L1 lexical attrition.