We learn new words via our everyday reading experience, but the precise mechanisms behind this learning are still unclear. In this experiment we tracked the development of lexical representations in adults combining behavioural measures of lexical processing with EEG signatures of visual word sensitivity. Participants learned novel letter strings using two different routines, one based on the standard explicit procedure typically used in the literature, and one based on a more pro-active feedback-based learning. Lexical integration was measured immediately after learning, and one day and one week post-learning. The two different learning methods proved to be equally effective. Participants showed lexical integration of novel word forms both in the behavioural and in the visual EEG task, suggesting that the brain becomes sensitive to lexical representations as it gets repeatedly exposed to written strings of letters.