Chapter 10: Auditory/Special Senses Flashcards
What is frequency? What is the standard measurement for it?
It is the number of cycles a wave completes in a given time; Hertz (1 hz = 1 cycle per second)
What range of sound do humans hear?
between 20-20k hz
What is amplitude? What is it’s basic measurement?
the stimulus intensity or loudness, graphically increased height; a decibel
What is the fundamental frequency? What is significant about it?
it is the rate at which a complex waveform repeats and it is the lowest common multiple of a higher set of tones; it is what we hear in complex sounds
What are overtones?
a set of higher frequency sound waves that vibrate at whole number integers of the fundamental frequency
What delivery speed of language is perceived as speech?
8-10 segments per second
What is prosody? What part of the brain is it perceived by?
the melodic tone of the speaking voice; the same part as music
What is the basilar membrane’s function in the hearing process?
it is the receptor surface in the cochlea that transduces sound to neural energy
What parts of the basilar membrane have peak vibration to high, medium and low frequencies?
High = the narrow, thick base Medium = middle Low = wide thin apex
How many inner and outer hair cells are there and how do they differ?
12k outer vs 3.5k inner; outer attached only loosely; inner are gone once you lose them; outer relax or contract to change the tectorial stiffness based on brain transmission
What are Otoacoustic emissions? What are they used for?
sound produced by the cochlea that moves out of the ear; used to detect hearing loss especially in infants
What pathway does audition take to the auditory cortex?
hair cells –> bipolar cells (auditory nerve) –> brainstem –> cochlear nucleus –> superior olive (some to trapezoid body) –> inferior colliculus –> medial geniculate nucleus –> auditory cortex
Where does the ventral pathway end up? What is it responsible for?
it ends up in the primary auditory cortex (area A1); and it is used it ID auditory stimuli
Where does the dorsal pathway end up? What is it responsible for?
in auditory corticol regions adjacent to area A1; it is involved in controlling movement related to sound
Where is area A1 located in the cortex?
Heschl’s gyrus
Where is area A2 located in the cortex and what is another named for it?
it is behind it and another name for it is the planum temporale
What is significant about the size of A2 and A1 on either side of the brain?
for right handed people A2 is larger on the left and Heschl’s gyrus is larger on the right
What area is located on the cortex of the left planum, located at the rear of the left temporal lobe? What is it responsible for?
Wernicke’s area; involved in language comprehension
What is special about left handers regarding the size of A1 and A2?
15% of them are the opposite of right handers and 15% of them have bilateral speech representation
What is the Insula and what does it do?
it is in the lateral fissure; it contains language and taste perception and is linked to areas with social cognition
What is tonotopic representation and how is it represented on the basilar membrane?
it is structural organization for processign sound waves from lower to higher frequencies; the thick base is higher frequencies and it gets lower towards the apex
Under what level of sound does the cochlea not respond in a tonotopic manner? How does it compensate?
below 200hz; the apex responds differently depending on the pitch
What are two ways to detect location?
Interaural time difference (ITD) and interaural intensity difference (IID)
How does ITD function and where does it?
by comparing how long it takes for the sound to reach either ear; located in the medial part of the superior olivary complex
How does the IID function?
the head acts as a obstacle and makes sounds quieter, the ear/brain pick up on this to locate the sound
What is the function of Broca’s area? Where is it located?
functions with the motor cortex to produce movements needed for speaking, it is also involved in DISCRIMINATION; located in the anterior left hemi (frontal lobe area)
What is Broca’s area and Wernicke’s area connected through?
arcuate fasciculus
What is Broca’s aphasia?
the inability to speak fluently despite normal comprehension and intact vocal mechanisms
What is Wernicke’s aphasia?
the inability to understand or produce language even with production intact
What are 2 other regions (besides Wernicke’s and Broca’s) involved in language?
the dorsal areas of frontal lobes and the areas of motor and somatosensory that control the face, tongue etc.
Where is the supplementary speech area? What happens when you stimulate it?
it is the dorsal surface of the left frontal lobe; it stops speech completely (Penfield)
What does the primary (A1) auditory are respond to compared to the secondary?
Primary: simple bursts of noise
Secondary: syllables and more complex sounds
Where is music production vs perception processed?
Production: left hemi
Perception: right hemi
Where are pitches compared in the brain?
the frontal lobe
What is amusia?
tone deafness
What are 2 areas significant to the neurobiology of bird song?
Higher vocal control centre (HVC) Robustus archistriatalis (RA)
What range of sounds do bats emit?
12k-200k hz
How are sensory systems organized? (3)
1) Hierarchically
2) Functional segregation
3) Parallel processing
What are the 2 types of Parallel processing?
1) Influence conscious behavior without conscious awareness
2) Influence behavior by engaging conscious awareness
What is a Fourier analysis?
a mathematical breakdown of complex waves in to component sine waves of different frequencies and amplitudes
What are characteristics of a pure tone?
the are sine waves, there is a close relationship between tone and pitch, more difficult to localize
How are hair cells depolarized? What happens?
movement of the fluid towards the tallest hair; cation channels open and there is a K+ which causes a NT to be released from the basilar membrane
What kind of information do outer hair cells receive and what do they use it for?
input from the brain to ear; affects the stiffness of the tectorial membrane
What part of the brain perceives differences in loudness?
the lateral superior olive; goes to superior collicus after (integrate with vision)
What part of the brain perceives difference in time of arrival?
the medial superior olive ; goes to superior collicus after (integrate with vision)
Where is the what pathway in the auditory cortex?
the prefrontal cortex
Where is the where pathway in the auditory system?
posterior parietal (use both visual and auditory)
What is endolymph? What is it rich in that allows action potential generation?
the fluid surrounding hair cells; it is rich in K+
How is sound localization organized in the superior colliculi?
retinotopically; allows for animals like barn owls to locate mice in dark
