Letter
Nature 453 1102-1106 (19 June 2008) | doi:10.1038/nature06910
Neural substrates of vocalization feedback monitoring in primate auditory cortex
Steven J. Eliades1 & Xiaoqin Wang1
1. Laboratory of Auditory Neurophysiology, Department of Biomedical
Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland
21205, USA
Correspondence to: Steven J. Eliades1Xiaoqin Wang1 Correspondence and requests
for materials should be addressed to S.J.E. (Email: or X.W.
(Email:
Abstract
Vocal communication involves both speaking and hearing, often taking place
concurrently. Vocal production, including human speech and animal vocalization,
poses a number of unique challenges for the auditory system. It is important
for the auditory system to monitor external sounds continuously from the
acoustic environment during speaking despite the potential for sensory masking
by self-generated sounds1. It is also essential for the auditory system to
monitor feedback of one's own voice. This self-monitoring may play a part in
distinguishing between self-generated or externally generated2, 3auditory
inputs and in detecting errors in our vocal production4. Previous work in
humans5, 6, 7, 8, 9, 10 and other animals11, 12, 13 has demonstrated that the
auditory cortex is largely suppressed during speaking or vocalizing. Despite
the importance of self-monitoring, the underlying neural mechanisms in the
mammalian brain, in particular the role of vocalization-induced suppression!
, remain virtually unknown. Here we show that neurons in the auditory cortex
of marmoset monkeys (Callithrix jacchus) are sensitive to auditory feedback
during vocal production, and that changes in the feedback alter the coding
properties of these neurons. Furthermore, we found that the previously
described cortical suppression during vocalization actually increased the
sensitivity of these neurons to vocal feedback. This heightened sensitivity to
vocal feedback suggests that these neurons may have an important role in
auditory self-monitoring.
http://www.nature.com/nature/journal/v453/n7198/full/nature06910.html
Editor's Summary
19 June 2008
Listen to yourself: Vocalization feedback monitoring
When we talk, we need to be able to both hear external stimuli, and keep track
of our own voice. In several species, including humans, auditory neurons are
suppressed during vocalization, but the function of this was unclear. New work
suggests that the 'suppressed' neurons are actually enhanced in their
sensitivity to self-generated sounds. Steven Eliades and Xiaoqin Wang found
that in freely behaving marmosets, neurons in the primary auditory cortex are
more sensitive to perturbations in vocal feedback despite the general
suppression. This suggests a possible mechanism for active monitoring of subtle
changes of your own voice. Deficits in such feedback monitoring have been
suggested as a cause for human speech disorders such as stuttering.
http://www.nature.com/nature/journal/v453/n7198/edsumm/e080619-15.html
Enjoy!
Xiao
XIAO, Jianqiang, Ph.D.
Research Associate
Psychology Department
Rutgers University
152 Frelinghuysen Road
Piscataway, NJ 08854
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