1 - Barn owl auditory localization Flashcards
(19 cards)
What do owls and humans use to localize sound sources?
Differences in sounds between left and right ears
This is fundamental for associating acoustic cues with spatial locations.
What is the main question regarding sound localization in the brain?
The form of the association in the brain and how specific neural circuits confer the ability to localize sounds.
What is Interaural Time Difference (ITD)?
The difference in time for sound to reach each ear, which aids in sound localization.
What is Interaural Intensity Difference (IID)?
The difference in loudness of a sound between the two ears, which helps determine elevation.
How do owls use inter-aural differences to code for specific locations in space?
They use inter-aural differences in timing (ITD) for azimuth and intensity (IID) for elevation.
What does azimuth refer to in sound localization?
The horizontal location of a sound source.
What does elevation refer to in sound localization?
The vertical location of a sound source.
What discovery was made regarding space-specific neurons in owls?
They are arranged into an auditory map in the inferior colliculus (IC).
Where do space-specific neurons first appear in barn owls?
In the External Nucleus of the Inferior Colliculus (ICx).
What determines the spatial receptive field of a neuron in ICx?
The tuning curves for interaural timing differences (ITD) and interaural intensity differences (IID).
What is the role of tuning curves in auditory neurons?
They predict the receptive fields based on specific combinations of ITD and IID.
What are the two principal pathways for processing auditory information in owls?
One pathway encodes timing cues (ITD) and another encodes intensity cues (IID).
What is phase locking in auditory neurons?
A mechanism that encodes timing differences as a phase delay.
What is the function of coincidence detectors in sound localization?
They fire maximally when inputs from the left and right ears arrive simultaneously.
How does Jeffress’ model convert a timing code to a place code?
By using delay lines that synchronize inputs from both ears to achieve coincidence detection.
What anatomical feature indicates the presence of delay lines in auditory pathways?
The axonal inputs from left and right ears to the laminar nucleus forming delay lines.
What is the significance of parallel processing in auditory localization?
It allows for simultaneous processing of timing and intensity cues without interference.
True or False: The auditory system can determine which ear a sound is leading and which is lagging.
False.
Fill in the blank: The owl’s brain has a mental map of how the noise fits into the _______.
[space around it].
