Processing unattended speech.

This study addresses the question of speech processing under unattended conditions. Dupoux et al. (2003) have recently claimed that unattended words are not lexically processed. We test their conclusion with a different paradigm : participants had to detect a target word belonging to a specific category presented in a rapid list of words, in the attended ear. In the unattended ear, concatenated sentences were presented, some containing a repetition prime presented just before the a target words. We found a significant priming effect of 22 ms (Experiment 1), for category detection in the presence of a prime compared with no prime. This priming effect was not affected by whether the right or the left ear received the prime (Experiments 2a and 2b). We also found that the priming effect disappeared when there was no pitch range difference between attended and unattended messages (Experiments 3 and 4). Finally, we replicated the priming effect by compellingwhen participants were compelled to focus on the attended message asking themin order to perform a second task (Experiment 5). The results demonstrate that priming can be produced by words in unattended continuous speech.