1 / 7

Inner Ear Dysfunction

Inner Ear Dysfunction. Upcoming Talk: Isabelle Peretz Musical & Non-musical Brains Nov. 22 @ 12 noon + Lunch Rm 2068B South Building. Neural Correlates of Stream Segregation. Summation of cortical response hypothesis

noe
Download Presentation

Inner Ear Dysfunction

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. Inner Ear Dysfunction Upcoming Talk: Isabelle Peretz Musical & Non-musical Brains Nov. 22 @ 12 noon + Lunch Rm 2068B South Building

  2. Neural Correlates of Stream Segregation • Summation of cortical response hypothesis • (DRAW) Will a stimulated area summate with another stimulated area on the tonotopic map? • Tetanic + rapid stimulation increases probability of summation (Fishman et al., 2001) ALTERNATIVELY? • Lesions of temporal cortex (in and around primary auditory cortex) (Peretz and colleagues, 1999; 2001) • Poster temporal gyrus affects melodic grouping • Intervals, melodic contours • Anterior temporal gyrus affects meter • Rhythmic grouping, temporal combinations

  3. Tinnitus: It has a certain ring to it (see Mencher pp. 144-145) • What is Tinnitus? • Ringing, buzzing, roaring, clicking experienced in one or both ears • Objective tinnitus • Audible to a third party • Stethoscope examination • Less than 5% of all tinnitus sufferers • Subjective tinnitus • Audible only to the patient • Subjective report • Approx. 35% of the population (continuous 15%) • Severe in 15% of tinnitus sufferers • Incidence increases with age & hearing loss • Noise-induced trauma

  4. Causes of Tinnitus • Vibratory • Acoustic stimulation of cochlea • Pulsatile tinnitus: Rhythmic pulsing, heartbeat • Leudet’s tinnitus: crackling of involuntary muscles • Jaw & neck position • Clicking tinnitus: Clicking sound that may occur with serous otitis media • May be objective or subjective • Non-vibratory • Neurochemical changes • Not traced to acoustic stimulation • Subjective tinnitus

  5. Physiological-subjective tinnitus (Jastreboff, 1990) • Cochlear causes • Increased otoacoustic emissions • Continuous spontaneous firing (4%) • Collapsing tectorial membrane • Chronic bent inner hair cells • Tetanic stimulation of auditory system • Reduced outer hair cell population • Inability to modulate gain • Chronic higher sensitivity to background noise • Hyperacusis: chronic oversensitivity (40% correlation) • Correlation with Sensori-neural hearing loss

  6. Higher-level Tinnitus(Lockwood et al., 1998) • Persistent symptoms after transection of auditory pathway • Cortical phenomenon? • fMRI evidence (blood flow) • Typical auditory stimulation = bilateral activation • Tinnitus causes unilateral activation • Modulation of tinnitus has unilateral effects • Neurochemical change in midbrain or cortex may contribute to tinnitus

  7. Summary & Treatments • Variety of contributing pathologies • Physical • Pinched blood vessel, loud-noise exposure, muscular activity, stress • Toxicity • Foods (allergic reactions), quinine, aspirin, cigarettes, alcohol, caffeine • Multiple causes • Treatments • Jaw position • Cutting cochlear nerve (50% effective) • Masking noise • Effectiveness of noise suggests no dementia • Hearing Aid use • Tinnitus retraining therapy • Habituation to tinnitus sound to reduce aversiveness

More Related