Daniela Neuhofer, Martin Stemmler & Bernhard Ronacher (2011): Neuronal
precision and the limits for acoustic signal recognition in a small neuronal
network. J. Comp. Physiol. A 197 (3), 251-265.
Abstract: Recognition of acoustic signals may be impeded by two factors:
extrinsic noise, which degrades sounds before they arrive at the receiver?s
ears, and intrinsic neuronal noise, which reveals itself in the
trial-to-trial variability of the responses to identical sounds. Here we
analyzed how these two noise sources affect the recognition of acoustic
signals from potential mates in grasshoppers. By progressively corrupting
the envelope of a female song, we determined the critical degradation level
at which males failed to recognize a courtship call in behavioral
experiments. Using the same stimuli, we recorded intracellularly from
auditory neurons at three different processing levels, and quantified the
corresponding changes in spike train patterns by a spike train metric, which
assigns a distance between spike trains. Unexpectedly, for most neurons,
intrinsic variability accounted for the main part of the metric distance
between spike trains, even at the strongest degradation levels. At
consecutive levels of processing, intrinsic variability increased, while the
sensitivity to external noise decreased. We followed two approaches to
determine critical degradation levels from spike train dissimilarities, and
compared the results with the limits of signal recognition measured in
behaving animals.
URL: http://www.springerlink.com/content/f01754v688068668/
For reprints please contact D. Neuhofer (email:
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