Kenneth S. Henry, Megan D. Gall, Gavin M. Bidelman & Jeffrey R. Lucas
(2011): Songbirds tradeoff auditory frequency resolution and temporal
resolution. J. Comp. Physiol. A 197 (4), 351-359.
Abstract: Physical tradeoffs may in some cases constrain the evolution of
sensory systems. The peripheral auditory system, for example, performs a
spectral decomposition of sound that should result in a tradeoff between
frequency resolution and temporal resolution. We assessed temporal
resolution in three songbird species using auditory brainstem responses to
paired click stimuli. Temporal resolution was greater in house sparrows
(Passer domesticus) than Carolina chickadees (Poecile carolinensis) and
white-breasted nuthatches (Sitta carolinensis), as predicted based on
previous observations of broader auditory filters (lower frequency
resolution) in house sparrows. Furthermore, within chickadees, individuals
with broader auditory filters had greater temporal resolution. In contrast
to predictions however, temporal resolution was similar between chickadees
and nuthatches despite broader auditory filters in chickadees. These results
and the results of a model simulation exploring the effect of broadened
auditory filter bandwidth on temporal resolution in the auditory periphery
strongly suggest that frequency resolution constrains temporal resolution in
songbirds. Furthermore, our results suggest that songbirds have greater
temporal resolution than some mammals, in agreement with recent behavioral
studies. Species differences in temporal resolution may reflect adaptations
for efficient processing of species-specific vocalizations, while individual
differences within species may reflect experience-based developmental
plasticity or hormonal effects.
URL: http://www.springerlink.com/content/336323467x5r6133/
For reprints please contact K. S. Henry (email:
Peter W. Alderks & Joseph A. Sisneros (2011): Ontogeny of auditory saccular
sensitivity in the plainfin midshipman fish, Porichthys notatus. J. Comp.
Physiol. A 197 (4), 387-398.
Abstract: The auditory system of the plainfin midshipman fish, Porichthys
notatus, is an important sensory receiver system used to encode
intraspecific social communication signals in adults, but the response
properties and function of this receiver system in pre-adult stages are less
known. In this study we examined the response properties of auditory-evoked
potentials from the midshipman saccule, the main organ of hearing in this
species, to determine whether the frequency response and auditory threshold
of saccular hair cells to behaviorally relevant single tone stimuli change
during ontogeny. Saccular potentials were recorded from three relative sizes
of midshipman fish: small juveniles [1.9?3.1 cm standard length (SL), large
juveniles (6.8?8.0 cm SL) and non-reproductive adults (9.0?22.6 cm SL)]. The
auditory evoked potentials were recorded from the rostral, middle and caudal
regions of the saccule while single tone stimuli (75?1,025 Hz) were
presented via an underwater speaker. We show that the frequency response and
auditory threshold of the midshipman saccule is established early in
development and retained throughout ontogeny. We also show that saccular
sensitivity to frequencies greater than 385 Hz increases with age/size and
that the midshipman saccule of small and large juveniles, like that of
non-reproductive adults, is best suited to detect low frequency sounds (<105
Hz) in their natural acoustic environment.
URL: http://www.springerlink.com/content/h15787406470310v/
For reprints please contact P. W. Alderks (email:
Kind regards
Sonja
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Dr. Sonja Amoser
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3400 Weidlingbach
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