PSYCH 3A03 Lecture Notes - Medial Geniculate Nucleus, Auditory Cortex, Cochlear Nucleus

• School: McMaster University
• Department: Psychology
• Course: PSYCH 3A03
• Professor: Paul Faure

Document Summary

Presentation of 2 tones is also informative on auditory function. Tone 1 presented @ cf of anf. Tone 2 presented off cf of anf. Varying the frequency and spl of tone 2 relative to tone 1 reveals regions of suppression in neural response. Amount of suppression caused by varying frequency and spl of tone 2 is visualized by plotting on neural tuning curve of tone 1. Cause of tone suppression is nonlinear motion of basilar membrane vibrations to 2 tones. One must be cautious in trying to predict responses of a neuron to a complex sound based on its responses to simple sounds. Can also measure two tone suppression effects on other spike parameters. E. g. spike synchrony (coefficient of synchronization), spike rate, etc. Fewer spikes and larger sound pressure levels in order for the ipsilateral tone to produce effects. Function of efferent auditory system is still not fully understood. Crossed olivocochlear bundle (cocb) fibers, from medial superior olive, are inhibitory.