Abstract
This study investigated the effect of aging on the dual task interference when an auditory task of answering to questions was combined with a visual search task. The study focused on the effect of unilateral auditory input, which is usually the case when we use cellular phone by applying it to one ear while driving. Participant's task was to detect a probe from among distracters. In the dual task condition, participant detected the probe, while listening to a simple open-ended question. Both younger and older participants showed comparable dual task interference in detection RT. In the older participants, however, the auditory task interfered with the probe detection more when they heard the questions with their left ear than when they did so with their right ear, suggesting that the dual task cost was especially large when they answered to question heard from their left ear.
