Semantic processing and memory for attended and unattended words in dichotic listening: behavioral and electrophysiological evidence.

Thirty-two Ss studied words presented to 1 ear, while ignoring a concurrent word list presented to the opposite ear. The N400 component of the event-related potentials elicited by attended words was modulated by semantic priming between successive words. The N400 elicited by unattended words was insensitive to semantic manipulation. Recognition memory was better for attended than for unattended words. However, the percentage of false positives was elevated equally for lures that were semantically related to "old" words, whether they had been attended or unattended. Words that were initially attended induced similar repetition effects in a lexical decision task as words that were initially unattended. Hence, both attended and unattended words are semantically processed and activate semantic representations. However, attended words from traces that are subsequently more available to conscious recollection than unattended words.