Magnetoencephalographic measurements (MEG) were used to examine the effect
on the human auditory cortex of removing specific frequencies from the acou
stic environment. Subjects listened for 3 h on three consecutive days to mu
sic "notched" by removal of a narrow frequency band centered on 1 kHz. Imme
diately after Listening to the notched music, the neural representation for
a 1-kHz test stimulus centered on the notch was found to be significantly
diminished compared to the neural representation for a 0.5-kHz control stim
ulus centered one octave below the region of notching. The diminished neura
l representation for 1 Id-it reversed to baseline between the successive li
stening sessions. These results suggest that rapid changes can occur in the
tuning of neurons in the adult human auditory cortex following manipulatio
n of the acoustic environment. A dynamic form of neural plasticity may unde
rlie the phenomenon observed here. (C) 1999 Published by Elsevier Science B
.V. All rights reserved.