Human auditory cortex responses to rising versus falling glides.
A 24-channel SQUID magnetometer was used to record signals from the right auditory cortex to tone glides with 16 different centre frequencies (ranging from 0.5 to 2 kHz), sweeping over one octave. The stimulus sequence, presented with an interstimulus onset interval of 0.6 s, consisted of infrequent 'deviant' rising (falling) glides and frequent 'standard' falling (rising) glides; the rising glides were identical to the falling glides but presented in the reverse direction. Deviant glides elicited significantly larger responses than standards at a latency of about 100 ms. This amplitude difference presumably arises from a mismatch response to the deviants. These results suggest that the auditory cortex extracts the direction of frequency transition even when the stimuli do not contain same frequencies.
Pardo
P J
PJ
Low Temperature Laboratory, Helsinki University of Technology, Espoo, Finland.
Sams
M
M
D000161:Acoustic Stimulation; D000328:Adult; D001303:Auditory Cortex / Q000502:physiology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D015225:Magnetoencephalography; D008297:Male