Multichannel waveforms and topographic mapping of the auditory brainstem response under common stimulus and recording...

Topographic representation of brain electrical activity may be employed to provide information about excitation patterns and symmetry of responses to sensory stimulation. The present investigation describes the waveforms and topographic distribution of the auditory brainstem response (ABR) in normal-hearing and neurologically-normal women during several stimulus and recording conditions using a multiple electrode array. Acoustic stimuli were rarefaction clicks presented monaurally at five intensities. Latencies and amplitudes for the sagittal and coronal electrodes as well as the topographies of waves I, III, and V were described. Wave I, in an ipsilateral inverting reference condition, exhibited smallest amplitudes at the temporal electrode ipsilateral to the stimulated ear and maximum voltage at electrode sites contralateral to the stimulated ear. Amplitude and latency patterns of wave III were peculiar to level of stimulation, ear of stimulation and selection of inverting electrode site. Wave III maximum voltage was detected at fronto-central scalp areas contralateral to the stimulated ear. Wave V latencies and amplitudes varied across electrode site and inverting electrode position. Its topography revealed maximum positive voltage at fronto-central electrodes, slightly asymmetric in some instances. Analysis of amplitude and topographic patterns of ABR components may provide useful information to supplement that provided by conventional displays of waveforms.