Irrelevant speech effect in aging: an assessment of inhibitory processes in working memory

The purpose of this study was to assess whether older adults can inhibit irrelevant auditory information while performing a span task. In Experiment 1, young and older participants recalled seven visually presented digits while subject to three types of irrelevant noise; white noise (nonverbal), and familiar and nonfamiliar language (verbal). A baseline measure was obtained in silence. The effect of each noise was also assessed under articulatory suppression (AS). In Experiment 2, the number of digits to recall was adjusted to participants' individual span. Results show a clear irrelevant speech effect (ISE), that is, recall declines in the presence of familiar and nonfamiliar verbal noise, but is unaffected by white noise. AS negates ISE. Most important, ISE does not interact with age: older adults have no more difficulty inhibiting irrelevant auditory information than do young adults. These results are discussed relative to current theories of inhibition in aging.