Effects of transient spatial attention on auditory event-related potentials.

Event-related potentials (ERPs) were recorded in subjects receiving left- and right-ear tones while they shifted attention to the left or right on a trial-by-trial basis. ERPs at attended compared with unattended tones revealed an enhanced negativity consisting of an early part that was parietally distributed and a later part with a frontocentral distribution. It may be concluded that these ERP modulations reflect the selection of auditory stimuli according to spatial criteria within a transient spatial attention situation. Furthermore, the attention-related negativity was not reduced for long inter-stimulus intervals (10 s) suggesting that prior stimulus exposure is not a basic requirement for eliciting attention-related negativity in the auditory modality.