# Coding of auditory space in the avian brain

> **NIH NIH R01** · ALBERT EINSTEIN COLLEGE OF MEDICINE · 2020 · $354,875

## Abstract

ABSTRACT
This revised renewal application carries on the study of how auditory space is encoded in the barn owl's
brain. The owl's specialization for capturing prey using auditory cues provides distinct advantages towards
elucidating the emergence of tuning properties and the neural code underlying sound localization. Spatial
cues are strongly frequency dependent. Additionally, location must be encoded in parallel with
spectrotemporal features which are used to infer the sound's identity. This means that the natural auditory
scene is multidimensional in its essence. This proposal approaches the coding of auditory space in this
compound context.
Aim 1 investigates the relationship between frequency and spatial tuning. We have found correlation
between the tuning of frequency and tuning to the spatial cue for the horizontal axis, interaural time
difference (ITD), in the map of auditory space of owl's midbrain. Correlation between frequency and ITD
tuning has also been observed in the brainstem and midbrain of mammals, which provides an avenue for
establishing links across species. This aim will investigate where the correlation emerges and how it
influences the response of midbrain tegmentum neurons, which readout the midbrain map to command
orienting behavior.
Aim 2 examines the integrated coding of sound direction and identity. Precision in coding sound identity will
be approached by examining the reproducibility of responses across sound repetitions. Our recent studies
suggest that reproducibility depends on sound direction and is enhanced in the processing pathway that
conveys information about interaural level difference (ILD). We will test these hypotheses in space-specific
neurons of the owl's midbrain usingin vivo extracellular and intracellular recordings and sound stimulation
in free field.
Aim 3 investigates the coding underlying the owl's head-orienting responses, taking into account the
dependency between frequency and ITD tuning and the location-dependent selectivity for sound identity
examined in aims 1 and 2 with modeling. The model will be guided by the hypothesis that a rate-code for
sound localization emerges by convergence from the map of auditory space onto midbrain tegmentum
neurons. This code is consistent with the rate code proposed for mammals. The model's predictions will be
tested using in vivo recordings in the midbrain and behavior.
This research will advance knowledge of how cues for sound location and sound identity are integrated in
the midbrain and provide a unifying theory linking the neural coding of ITD across species. Understanding
cue integration in central auditory processing will lead to more accurate interpretations of auditory
perception and hearing disorders, allowing for the design of more efficient treatments.

## Key facts

- **NIH application ID:** 9823873
- **Project number:** 5R01DC007690-16
- **Recipient organization:** ALBERT EINSTEIN COLLEGE OF MEDICINE
- **Principal Investigator:** Jose L Pena
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $354,875
- **Award type:** 5
- **Project period:** 2005-09-01 → 2021-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9823873

## Citation

> US National Institutes of Health, RePORTER application 9823873, Coding of auditory space in the avian brain (5R01DC007690-16). Retrieved via AI Analytics 2026-06-01 from https://api.ai-analytics.org/grant/nih/9823873. Licensed CC0.

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