Megan D. Gall, Kenneth S. Henry & Jeffrey R. Lucas (2012): Two measures of
temporal resolution in brown-headed cowbirds (Molothrus ater). J. Comp.
Physiol. A 198 (1), 61-68.
Abstract: Studies of auditory temporal resolution in birds have
traditionally examined processing capabilities by assessing behavioral
discrimination of sounds varying in temporal structure. Here, temporal
resolution of the brown-headed cowbird (Molothrus ater) was measured using
two auditory evoked potential (AEP)-based methods: auditory brainstem
responses (ABRs) to paired clicks and envelope following responses (EFRs) to
amplitude-modulated tones. The basic patterns observed in cowbirds were
similar to those found in other songbird species, suggesting similar
temporal processing capabilities. The amplitude of the ABR to the second
click was less than that of the first click at inter-click intervals less
than 10 ms, and decreased to 30% at an interval of 1 ms. EFR amplitude was
generally greatest at modulation frequencies from 335 to 635 Hz and
decreased at higher and lower modulation frequencies. Compared to data from
terrestrial mammals these results support recent behavioral findings of
enhanced temporal resolution in birds. General agreement between these AEP
results and behaviorally based studies suggests that AEPs can provide a
useful assessment of temporal resolution in wild bird species.
URL: http://www.springerlink.com/content/m05728136542tm22/
For reprints please contact M. D. Gall (email:
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Sonja Amoser
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