ear to brain Flashcards
chapter 11
main pathway
type 1 nerve fibers –> cochlear nucleus –> contralateral inferior colliculus –> medial geniculate body –> auditory cortex
other main pathway
type 1–> conchlear nucleus –>contralateral superior olivary complex –>inferior colliculus –> MGB –> auditory cortex
secondary pathway
stay on ipsilateral to cochlear nucleus, to superior olivary to iferior colliculus to mgb to auditory cortex
cochlear nucleus
structure in the brain stem that recives signals from type 1 nerve fibers of the ipsilateral ear
inferior colliculus
structure in midbrain along the pathway
medial geniculate body
in the thalamus and is a stop in the pathway
superior olivary complex
structure in the brain stem (pons) that receives signals from the cochlear nuclei
- codes localization based on time and intensity
descending pathway
inhibitory neural signals from the olivary complex go to the outer hair cells to cause a reduction in the motile response to modify amplification for loud sounds
where is the auditory cortex
in lateral sulcus above the temporal lobe
contents of the auditory cortex
- auditory core regions (A1 and core)
- belt
- parabelt
tonotopic map
the neurons in the auditory core regions are arranged by similar frequencies in order (low to high)
tunning of neurons
they can be broad or narrow
- narrow only respond to small bands on either side of their chracteristic frequency
- broad bands will be narrower with lower amplitudes
belt and parabelt function
can code for complex sounds with multiple frequencies
- broadly tuned neurons for this
primary auditory cortex
- related to pitch perception
what pathway
- responsible for recogntion of sounds
- belt to parabelt to anterior temporal cortex
