This study examined the effects of selective attention versus stimulus competition on the late auditory evoked potential (LAEP) in 20 young and 20 elderly listeners. In a series of test runs, different oddball tonal sequences were presented to one or both ears, and listeners were instructed to attend to tones at a specific target ear. Peak amplitudes were recorded for the N1, P2, and the early and late N2 components of the LAEP. Significant attention effects were found for all four components. N1 amplitudes increased significantly when participants attended to the target stimuli, whereas the amplitudes of P2, N2e, and N2l decreased. For all LAEP components except N2l, the attention effect did not differ between young and elderly listeners. Significant competition effects also were found for all four components. Amplitudes were significantly larger in monaural than binaural conditions for all components except N2l. The magnitude of this competition effect also was significantly larger for the young listeners than the elderly for all components except N1. These results suggest that the ability to attend selectively to sounds may be more resistant to normal aging than are effects related to stimulus competition.
Correction of response error versus stimulus error in the extinction of discriminated operant learning.
