Auditory stimuli. The standard or background stimulus was a train of brief sounds 25 ms in duration, 800 Hz in frequency, and 65 dB SPL in sound pressure. The test stimulus to evoke change-related cortical responses was a similar train of 10 brief sounds of 70 dB. One brief sound was inserted before the test stimulus as a prepulse.
Inui et al. BMC Neuroscience 2012 13:135 doi:10.1186/1471-2202-13-135