1. Sound Localization in the Barn Owl (maybe relation to Vision)
Laurene Dampare
Sensory Genomics Final Project

2. Introduction
The asymmetrical design of the Barn Owl's ears is essential for pinpointing its prey in the dark.
-The right ear points slightly upward, and the left ear is
naturally pointed slightly downward.
Sound reaches one ear before the other, with a resulting interaural time difference or ITD
-The difference in arrival time of a sound between two ears.
As humans have a visual map in the brain, the owl also possesses a visual and auditory map.

3. Methods
Eric Knudsen and Konishi undertook a series of experiments in 1977
This was done by probing the brains of anesthetized owls with fine electrodes
A remote-controlled sound speaker was moved to different locations around the owl's head along an imaginary sphere
Firing of neurons in the vicinity of the electrodes was recorded.
This was done over several months
Findings
Cells in the midbrain of the birds containing
cells called space-specific neurons would fire in
response to sound from a particular location.
Cells were organized in a precise topographic
array, similar to maps of cells in the visual cortex of the brain.
But this had a horizontal as well as vertical coordinate system

4. Do sound inform or sight inform sound?
Birds raised with ear plugs
Birds raised with glasses

5. Sources
Carr, C. E. and Konishi, M. (1990) A Circuit for Detection of Interaural Time Differences in the Brain Stem of the Barn Owl. The Journal of Neuroscience. 70(10):
Knudsen, E. I and Knudsen, P.F. (1989), Vision calibrates sound localization in developing barn owls. Journal of Neuroscience. 09:
Knudsen, E. I., and M. Konishi (1979) Mechanisms of sound localization in the barn owl. Journal of Comparative Physiology. 133:
Payne S. Roger. (1971), Acoustic location of prey by the barn owl. Journal of Experimental Biology. 54. S3S-573