Abstract
The study investigated the effect of unintentional learning of semantically unrelated word pairs on event-related brain potentials. Two experiments were conducted, in whose acquisition phase participants listened to five word pairs of semantically unrelated words, each pair being repeated twenty times. In the test phase of Experiment I, these “old” pairs were presented mixed with “new” pairs containing other words. In the test phase of Experiment II a third condition was added in which the first word in a pair was one of the words presented during acquisition but the second word was new. In both experiments the second word in new word pairs elicited a large negative deflection identified as an N400, whose amplitude in Experiment II did not depend on whether the first word was old or new. The result is primarily caused by building new associations between words, while the repetition effect played a relatively minor role.