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Stereotactically-guided Ablation of the Rat Auditory Cortex, and Localization of the Lesion in the Brain
Published on: October 11, 2017
Auditory cortex tracks the temporal regularity of sustained noisy sounds
Bernd Lütkenhöner1, Annemarie Seither-Preisler, Katrin Krumbholz
1Section of Experimental Audiology, ENT Clinic, Münster University Hospital, Kardinal-von-Galen-Ring 10, D-48129 Münster, Germany. Lutkenh@uni-muenster.de
Hearing Research
|November 16, 2010
Summary
This study reveals a brain response asymmetry to sound regularity changes. The auditory cortex shows a strong onset response but a weak offset response, suggesting environmental monitoring.
Area of Science:
- Neuroscience
- Auditory Neuroscience
- Cognitive Neuroscience
Background:
- Neuroimaging studies reveal significant asymmetries in auditory cortex responses to temporally regular versus irregular sounds.
- Previous research indicated a pronounced temporal-regularity onset response (TRon) but a minimal temporal-regularity offset response (TRoff).
Purpose of the Study:
- To investigate the onset/offset asymmetry in auditory cortex responses with enhanced statistical power.
- To re-evaluate the mechanisms underlying the observed asymmetry in temporal-regularity processing.
Main Methods:
- Utilized neuroimaging techniques with increased power to examine auditory cortex responses.
- Analyzed the temporal dynamics of brain activity related to the onset and offset of temporally regular sounds.
Main Results:
- Confirmed a dramatic asymmetry between onset and offset responses in the antero-lateral Heschl's gyrus.
- Identified that the offset response is primarily due to the rapid breakdown of a sustained temporal-regularity response (TRsus), not higher-level processing.
- Observed a variable amplitude ratio between the transient onset response (TRon) and TRsus.
Conclusions:
- The rapid decay of sustained activity underlies the weak offset response, suggesting minimal involvement of higher cortical areas.
- Temporal-regularity processing in the auditory cortex may play a role in environmental monitoring and detecting behaviorally relevant stimuli, such as animate sources.
Related Concept Videos
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The auditory system is essential for sound perception, utilizing various critical structures. When sound waves enter the outer ear, they travel through the ear canal and cause the eardrum to vibrate. These vibrations are then transmitted to the middle ear, where three tiny bones – the malleus, incus, and stapes – amplify the sound. This amplification is crucial, as it ensures that the sound vibrations are strong enough to be conveyed to the inner ear. These vibrations then reach the cochlea, a...
01:21Perceiving Loudness, Pitch, and Location
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01:13The Cochlea
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01:01Perception of Sound Waves
The human ear is not equally sensitive to all frequencies in the audible range. It may perceive sound waves with the same pressure but different frequencies as having different loudness. Moreover, the perception of sound waves depends on the health of an individual's ears, which decays with age. The health of one's ears may also be affected by regular exposure to loud noises.
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