Lexical Contributions to Retention of Verbal Information in Working Memory: Event-Related Brain Potential Evidence

The present study investigated whether lexical codes contribute to retention of verbal information in working memory. We used event-related brain potentials (ERPs) recorded while participants were performing a serial recall task to show differences in brain activity during retention of words or pseudowords. The effects of lexical status and memory load (task difficulty) upon ERP activity during retention also differed, with memory load affecting ERP indices of phonological processing. The timing of the ERPs suggested that the influence of lexical status upon retention began during encoding. The contrast between ERPs in the serial recall task and in a control task with negligible memory demand indicated that the effect of lexical status in the retention interval of the memory task was specific to consciously controlled memory operations. These results support the view that lexical codes actively contribute to retention of words in working memory. © 1999 Academic Press