MODULATION OF EVENT-RELATED POTENTIALS BY WORD REPETITION - THE ROLE OF VISUAL SELECTIVE ATTENTION

Event-related potentials (ERPs) were recorded while subjects viewed vi sually presented words, some of which occurred twice. Each trial consi sted of two colored letter strings, the requirement being to attend to and make a word/nonword discrimination for one of the strings. Attent ion was manipulated by color in Experiment 1, and color and a precue w ere used in Experiment 2. As in previous ERP studies of word repetitio n, a positive offset to repeated words developed when both first and s econd presentations were the focus of attention. In Experiment 2, ERPs showed evidence of positive-going repetition effects in all condition s in which at least one of the two presentations of the repeated word was attended. In the visual modality, the positive-going ERP repetitio n effect occurs only when at least one of the two presentations of a r epeated item is the object of attention, which suggests that one or mo re of the processes reflected by the effect is capacity limited.