1 / 28

Auditory Physiology 2

Auditory Physiology 2. PSY 295 – Sensation & Perception Christopher DiMattina , PhD. Hearing. Auditory nerve. The auditory nerve . The auditory nerve receives input from hair cells We characterize auditory nerve fibers by their responses to pure tone stimuli. Auditory nerve fibers.

elsu
Download Presentation

Auditory Physiology 2

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Auditory Physiology 2 PSY 295 – Sensation & Perception Christopher DiMattina, PhD

  2. Hearing PSY 295 - Grinnell College - Fall 2012

  3. Auditory nerve PSY 295 - Grinnell College - Fall 2012

  4. The auditory nerve • The auditory nerve receives input from hair cells • We characterize auditory nerve fibers by their responses to pure tone stimuli PSY 295 - Grinnell College - Fall 2012

  5. Auditory nerve fibers • Tone frequency which increases the neuron’s firing rate at lowest intensity is the characteristic frequency (CF) PSY 295 - Grinnell College - Fall 2012

  6. Nonlinear interactions • Two-tone suppression – playing a second tone of a slightly different frequency can suppress responses to a CF tone • Arises from mechanics of basilar membrane PSY 295 - Grinnell College - Fall 2012

  7. Rate-intensity functions • Auditory nerve fibers increase their firing rate as a function of CF tone level • High spontaneous rate fibers and low spontaneous rate fibers PSY 295 - Grinnell College - Fall 2012

  8. Temporal code for frequency • Auditory nerve fibers phase-lock to tones at lower frequencies • Phase locking becomes inconsistent at higher frequencies due to ANF refractory period PSY 295 - Grinnell College - Fall 2012

  9. Volley principle • Even if individual neurons cannot lock, their total responses can lock to provide a temporal code for sound PSY 295 - Grinnell College - Fall 2012

  10. Central auditory system PSY 295 - Grinnell College - Fall 2012

  11. Central auditory pathway PSY 295 - Grinnell College - Fall 2012

  12. Cochlear nucleus • Receives inputs from the auditory nerve • Diverse cell types with variety of response properties • Some cells tuned to the location of spectral notches, which are an important cue for vertical sound localization PSY 295 - Grinnell College - Fall 2012

  13. Superior olive • First stage where inputs from both ears come together • Important to integrate binaural inputs for sound localization PSY 295 - Grinnell College - Fall 2012

  14. Sound localization PSY 295 - Grinnell College - Fall 2012

  15. Inferior colliculus PSY 295 - Grinnell College - Fall 2012

  16. Inferior colliculus • Complex auditory processing • Neurons sensitive to complex sounds like amplitude-modulated and frequency-modulated stimuli • Performs complex integration of spectral energy PSY 295 - Grinnell College - Fall 2012

  17. Thalamus • Medial geniculate body of thalamus exhibits tonotopic organization and provides input to primary auditory cortex PSY 295 - Grinnell College - Fall 2012

  18. Auditory cortex PSY 295 - Grinnell College - Fall 2012

  19. Tonotopic organization in A1 PSY 295 - Grinnell College - Fall 2012

  20. Auditory cortex responses • Neurons sensitive to more complex spectral-temporal combinations of sound • Two tone pips at specific time delay and frequency difference PSY 295 - Grinnell College - Fall 2012

  21. Auditory cortex • Cells sensitive to musical pitch PSY 295 - Grinnell College - Fall 2012

  22. Hearing loss PSY 295 - Grinnell College - Fall 2012

  23. Hearing loss • 30 million Americans suffer some form of hearing loss • Typically this means elevated thresholds • Many kinds of hearing loss PSY 295 - Grinnell College - Fall 2012

  24. Conductive hearing loss • Middle ear bones are impaired • Middle ear fills with mucus during inner ear infections (otitis media) • Otosclerosis– abnormal bone growths PSY 295 - Grinnell College - Fall 2012

  25. Sensorineural hearing loss • Damage to hair cells or auditory nerve • Exposure to loud sounds • Ototoxic drugs PSY 295 - Grinnell College - Fall 2012

  26. Environmental noise and hearing PSY 295 - Grinnell College - Fall 2012

  27. Hearing aids amplify and compress sounds PSY 295 - Grinnell College - Fall 2012

  28. Cochlear implants PSY 295 - Grinnell College - Fall 2012

More Related