GRAVITY DEPENDENT CORTICAL CONTROL OF SENSATION
Abstract
Abstract When comparing human performance in weightless conditions versus performance in gravity, a striking difference is observed for tasks that involve the vestibular system, notably tasks related to orientation. The vestibular system also has a great influence on sound localization, both the semicircular canals and the otolith organs influence the perceived head relative locations of sounds. Here we aim to characterize the dependency of active hearing on vestibular conditions and to examine the hypothesized functioning of cortico–inner-ear control loops. The case study is speaker segregation, in upright and supine conditions. We hypothesize an attention driven, cortico-cochlear loop, where attention steers the cortical pitch estimator to the pitch cues of the attended speaker, and that the output of the pitch estimator is fed back to the cochlear outer-hair-cells (OHCs), enhancing the surroundings of the harmonic components of the attended-speaker while suppressing all other components. Given the role of the vestibular organs and their endolymphatic continuity with the cochlea, a question arises whether a common link exists between semicircular canal interpretation and the cortico-cochlear control circuit. To answer this question, we shall measure the effect of the cortico-cochlear control on OHC responses as a function of body orientation with respect to gravity. Finding a decrease in cortical control of the OHCs in the supine orientation would mirror the concomitant decrease in body spatial position awareness experienced under this condition and would strongly support the hypothesized common link.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 20, 2023
- Source ID
- FA95502210346
Entities
People
- Oded Ghitza
Organizations
- Air Force Office of Scientific Research
- Boston University
- United States Air Force