Auditory P50 obtained with a repetitive stimulus paradigm shows suppression to high-intensity tones.
We manipulated stimulus intensity and number of frequency bands in auditory stimuli in order to investigate the nature of P50 in human auditory evoked potentials. Pure-tone and mixed-tone conditions were examined. For each condition, four stimulus intensities were used: 55, 70, 85 and 100 dB sound pressure level (SPL). The P50s were obtained at Cz using a repetitive stimulus paradigm. P50 amplitudes increased as stimulus intensities increased up to 85 dB; with 100 dB stimulation amplitudes decreased. The number of frequency bands in the stimulus did not affect P50 amplitude. Considered in terms of P50 suppression under a conditioning/testing paradigm, the results suggest that the P50 wave reflects activity of the sensory gating mechanism in humans.
Ninomiya
H
H
Department of Neuropsychiatry, Graduate School of Medical Science, Kyushu University, Fukuoka, Japan. ninoh@npsych.med.kyushu-u.ac.jp
Sato
E
E
Onitsuka
T
T
Hayashida
T
T
Tashiro
N
N
D000328:Adult; D001301:Audiometry, Pure-Tone / Q000379:methods*; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male