Discourse Focus and Memory Encoding: The Role of Trial-Level Alpha Power

The rapid, continuous flow of spoken language places strong demands on attention, and it is thought that listeners meet these demands by predicting when important information will occur and allocating attention accordingly. However, to date there is little direct evidence for the involvement of preparatory attention during language processing. In this study, we investigate preparatory attention during spoken language comprehension by measuring alpha neural activity with EEG, a known measure of temporal attentional preparation. Alpha activity leading up to target words that were either focused or defocused by a preceding discourse question did not vary as a function of focus, challenging the assumption that attention is pre-allocated to the timing of focused words. On the other hand, we found that trial-by-trial fluctuations in alpha activity predicted both the depth of processing and the subsequent memory for new information. Specifically, pre-target alpha modulated a centro-parietal Dm subsequent memory effect for focused words, linking preparatory attention to memory encoding during comprehension. Together, these findings bridge psycholinguistic studies on information structure and cognitive neuroscience research on temporal attention, offering novel insights into the role of alpha activity in attentional dynamics during spoken language processing.