Modulation of event-related brain potentials by word repetition: effects of local context.

In four experiments, event-related brain potentials (ERPs) were evoked by visually presented word pairs in a task requiring responses to occasional target pairs. In Experiments 1 and 2, some pairs comprised items that had been presented previously. These repeated pairs consisted of words that had been paired together when first presented (same context condition) or words that had first been presented on consecutive trials (different context condition). ERP repetition effects were equivalent in the two conditions. In Experiment 3, same-context repeats were contrasted with a condition in which a repeated word was paired with a new word. Only the same-context pairs evoked a repetition effect. Experiment 4 showed that repetition effects to different- and same-context repeats remained equivalent when first presentations of the members of different-context pairs were separated by six intervening trials. We conclude that the ERP repetition effect shows little sensitivity to local context.