Neural responses to tones in the mammalian primary auditory cortex (A1) exhibit adaptation over the course of several seconds. Important questions remain about the taxonomic distribution of multi-second adaptation and its possible roles in hearing. It has been hypothesized that neural adaptation could explain the gradual "build-up" of auditory stream segregation. We investigated the influence of several stimulus-related factors on neural adaptation in the avian homologue of mammalian A1 (field L2) in starlings (Sturnus vulgaris). We presented awake birds with sequences of repeated triplets of two interleaved tones (ABA-ABA-...) in which we varied the frequency separation between the A and B tones (ΔF), the stimulus onset asynchrony (time from tone onset to onset within a triplet), and tone duration. We found that stimulus onset asynchrony generally had larger effects on adaptation compared with ΔF and tone duration over the parameter range tested. Using a simple model, we show how time-dependent changes in neural responses can be transformed into neurometric functions that make testable predictions about the dependence of the build-up of stream segregation on various spectral and temporal stimulus properties.
|Original language||English (US)|
|Number of pages||15|
|Journal||Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology|
|State||Published - 2010|
Bibliographical noteFunding Information:
Acknowledgments The care and treatment of the animals were in accordance with the procedures of animal experimentation approved by the Bezirksregierung Weser-Ems. This work was supported by National Science Foundation grant INT-0107304, by National Institute on Deafness and Other Communication Disorders (NIDCD) grant R01 DC 009582, and a fellowship from the McKnight Foundation to MAB, NIDCD grant R01 DC 07657 to Shihab A. Shamma, CM and AJO, and by Deutsche Forschungsgemeinschaft SFB/TRR31 to GMK.
- Auditory stream segregation
- Sturnus vulgaris