The effects of lesions of the bulbar auditory system on several auditory discriminations

Thesis (Ph.D.)--Boston UniversityPLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.This study stems from reports in the experimental literature that selective destruction of portions of the ventral acoustic system of the medulla produced differential effects on sound-based behavior. It has been shown that destruction of the nucleus of the trapezoid body or its afferent fibers resulted in a decrement in the strength of responding which terminated an intense noise signal. whereas auditory threshold to noise was not significantly affected. Bxtensive destruction of all the nuclear and fiber components of the ventral acoustic system raised the threshold substantially and produced a reduction in responding on the noise-termination task. The two problems approached in this thesis were to discover other aspects of audition which would be differentially affected by destruction of selected portions of the ventral acoustic system. and to define precisely the neural damage required to produce substantial shifts in auditory threshold. The subjects were albino rats. The experimental chamber was a wire mesh cage which contained a lever and food cup. A loudspeaker and light source were mounted on the roof of the cage. This apparatus and a pellet dispenser were enclosed in a sound-resistant, light-proof bax. [TRUNCATED]2031-01-0