[The effects of selective attention to tone pips and speech messages upon event-related potential (author's transl)]

Event-related potentials to tone pips were recorded while subjects listened selectively to one of four kinds of stimuli. High tone pips and a message in female voice were mixed and presented to one ear, and low tones and a message in male voice to the other ear. When attention was directed to tones, a slow negative shift was observed to be superimposed on the N1 (and P2) component evoked by the attended tones; when attention was switched to messages, those N1 and P2 amplitudes to tones in attended and unattended ears were reduced. The attention-related reduction of N1 and P2 amplitudes and the development of the negativity were interpreted in relation to early and late stages of the human information processing.