Left hemispheric dominance during auditory processing in a noisy environment.
BACKGROUND
In daily life, we are exposed to different sound inputs simultaneously. During neural encoding in the auditory pathway, neural activities elicited by these different sounds interact with each other. In the present study, we investigated neural interactions elicited by masker and amplitude-modulated test stimulus in primary and non-primary human auditory cortex during ipsi-lateral and contra-lateral masking by means of magnetoencephalography (MEG).


RESULTS
We observed significant decrements of auditory evoked responses and a significant inter-hemispheric difference for the N1m response during both ipsi- and contra-lateral masking.


CONCLUSIONS
The decrements of auditory evoked neural activities during simultaneous masking can be explained by neural interactions evoked by masker and test stimulus in peripheral and central auditory systems. The inter-hemispheric differences of N1m decrements during ipsi- and contra-lateral masking reflect a basic hemispheric specialization contributing to the processing of complex auditory stimuli such as speech signals in noisy environments.
Okamoto
Hidehiko
H
Institute for Biomagnetism and Biosignalanalysis, University of Muenster, Muenster, Germany. okamotoh@uni-muenster.de
Stracke
Henning
H
Ross
Bernhard
B
Kakigi
Ryusuke
R
Pantev
Christo
C
D000161:Acoustic Stimulation; D000328:Adult; D054022:Cerebrum / Q000502:physiology*; D005072:Evoked Potentials, Auditory; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D009622:Noise; D010470:Perceptual Masking