Quiz4 Flashcards
Evidence for Speech is Special
-It is processed and handled by the brain in a unique way
-Speech is processed in its own special regions of the brain
-Broca’s area and Wernicke’s area (production and comprehension). Speech is impaired with lesions here
Evidence Against Speech is Special
-It is processed like any other learned pattern
-Musicians (but not non-musicians) also process music in these regions (more than speech being processed here)
What Makes Speech Redundant
There is a lot of information with speech and you don’t need all that information
In what situations is redundancy important?
Speech in noisy environment. You can understand speech even when missing some information
How categorical perception is related to instructions
-If the listener is tasked with identifying two different sounds, they will task them into binary categories despite a gradual change.
-If tasked with identifying if a sound is a good prototype, people are able to rate which speech token is a good example of a phoneme. Generally not categorical here.
Where Else is Redundancy seen?
Crickets do this to distinguish between mates and predators
Neural Network
-When a group of neurons cause another neuron to fire, the connection between them strengthens
-aka Hebbian learning
-Categorical perception naturally comes out of this, so it shows speech is not special
Perceptual Magnet
-It is more difficult to distinguish speech tokens that are near the syllable prototype (acoustically similar)
-Bird prototype example: Robin is a bird, ostrich is also a bird
-Different from categorical perception because categorical perception has distinct categories that separate the phonemes
Ototoxicity Definition
Medicines that can damage hair cells
Ototoxicity damage
Damages…
-Inner hair cells
-Outer hair cells
via buildup of reactive oxygen species causing cell death
Ototoxic Medication Examples
-Gentamicin (anitbiotic) (damages IHC)
-Cisplatin (cancer) (damages OHC, spiral ganglion, and stria)
-Vicoden (pain)
-NSAIDs (pain) (less BM movement)
Noise Exposure Effects
-Noise exposure drives metabolic activity
-Causes buildup of reactive oxygen species causing cell death of stria vascularis (key for endolymph) and OHC
-Reduces blood flow to cochlea which deprives cells of needed oxygen
-Earbuds drive louder volumes (closer to TM)
-Lower concentration gradient of K+ in endolymph, less drive for K+ to flow in
Connexin 26 Mutation
-Critical for forming gap junctions that maintain K+ concentration in endolypmh
-Endolymph and perilymph start mixing
DFNB12 Mutation
-Progressive loss of tiplinks in animals
-Results in congenital deafness in humans
Auditory Neuropathy
-Reflects problems with the transmission for signals from the cochlea to the brain
-Related to a decrease in the synchrony of firing in the auditory nerve (lose temporal information)
-Normal OAEs, abnormal ABR
-Normal pure-tone thresholds, but struggle in noisy environments
-Difficulty with gap detection
-Can treat with cochlear implants (increasing synchrony with lots more neurons firing)
Meniere’s disease
-Caused by excess fluid in the inner ear
-Vertigo
-Hearing loss
-Aural fullness
-Tinnitus
-Treatments still being researched
Acoustic Neuroma
-Tumor on CN VIII
-Slow growing and benign
-Reason for a patient with asymmetric loss to get an MRI
-If grown too large, needs to be removed, cutting CN VIII causing hearing loss
Wernicke’s Aphasia
-Comprehension problem
-Fluent but generally meaningless speech
Tumors
Benign but can push against structures as they grow along auditory pathway
Neurofibromatosis Type 2 (NF2)
-Genetic disorder that results in a proliferation of tumors in the nervous system (tumors on CN VIII too)
-Hearing loss
-Tinnitus
-Balance problems
-Numbness/Weakness
-Headache and seizure
-Cataracts
NF2 Treatment
More about management
-Annual MRI
-Annual vision and hearing checks
Presbycusis
-Age-related hearing loss
-Environmental component of loudness and duration of sounds exposed to over a lifetime
-Genetic component too
-Periphery and central damages
