Behavioral detection of spatial stimuli is reflected in auditory cortical dynamics

We studied the cortical processing of spatial stimuli by magnetoencephalographic (MEG) measurements using broadband noise bursts presented from eight sound source directions in the horizontal plane. The stimuli were individually created for each subject by using three-dimensional (3D) sound techniques. The subjects carried out a behavioral task where their accuracy for localizing the 3D stimuli was established. We found that the auditory N100m response was sensitive to the sound source direction, exhibiting contralaterally more preponderant responses in both the left and the right hemisphere. Generally, responses were more prominent in the right hemisphere. The behavioral performance of the subjects correlated positively with N100m amplitude organization, showing that the dynamics of auditory cortex predict behavioral sound detection.