Effects of the critical band on auditory-evoked magnetic fields.
Changes in the bandwidth affect the perceived loudness of a stimulus even when the level of the stimulus remains fixed. If the bandwidth of a sound is varied while maintaining the overall intensity, the loudness remains constant as long as the bandwidth is less than the critical bandwidth. If the bandwidth is increased beyond the critical bandwidth, the loudness increases with increasing bandwidth. Human cortical responses as a function of stimulus bandwidth were examined by recording auditory-evoked magnetic fields. The results showed that the N1m magnitudes, that is, the estimated equivalent current dipole moments, increased with increasing bandwidth when the bandwidth was increased beyond the critical bandwidth.
Soeta
Yoshiharu
Y
Institute for Human Science and Biomedical Engineering, National Institute of Advanced Industrial Science and Technology, Osaka, Japan. y.soeta@aist.go.jp
Nakagawa
Seiji
S
Matsuoka
Katsunori
K
D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D001303:Auditory Cortex / Q000502:physiology* / Q000528:radiation effects; D001931:Brain Mapping; D004307:Dose-Response Relationship, Radiation; D005072:Evoked Potentials, Auditory / Q000502:physiology* / Q000528:radiation effects; D006801:Humans; D008144:Loudness Perception / Q000502:physiology* / Q000528:radiation effects; D015225:Magnetoencephalography; D011930:Reaction Time / Q000502:physiology / Q000528:radiation effects; D013057:Spectrum Analysis