Chapter 10: Auditory/Special Senses

Question 1

What is frequency? What is the standard measurement for it?

Answer 1

It is the number of cycles a wave completes in a given time; Hertz (1 hz = 1 cycle per second)

Question 2

What range of sound do humans hear?

Answer 2

between 20-20k hz

Question 3

What is amplitude? What is it’s basic measurement?

Answer 3

the stimulus intensity or loudness, graphically increased height; a decibel

Question 4

What is the fundamental frequency? What is significant about it?

Answer 4

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

Question 5

What are overtones?

Answer 5

a set of higher frequency sound waves that vibrate at whole number integers of the fundamental frequency

Question 6

What delivery speed of language is perceived as speech?

Answer 6

8-10 segments per second

Question 7

What is prosody? What part of the brain is it perceived by?

Answer 7

the melodic tone of the speaking voice; the same part as music

Question 8

What is the basilar membrane’s function in the hearing process?

Answer 8

it is the receptor surface in the cochlea that transduces sound to neural energy

Question 9

What parts of the basilar membrane have peak vibration to high, medium and low frequencies?

Answer 9

High = the narrow, thick base
Medium = middle
Low = wide thin apex

Question 10

How many inner and outer hair cells are there and how do they differ?

Answer 10

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

Question 11

What are Otoacoustic emissions? What are they used for?

Answer 11

sound produced by the cochlea that moves out of the ear; used to detect hearing loss especially in infants

Question 12

What pathway does audition take to the auditory cortex?

Answer 12

hair cells –> bipolar cells (auditory nerve) –> brainstem –> cochlear nucleus –> superior olive (some to trapezoid body) –> inferior colliculus –> medial geniculate nucleus –> auditory cortex

Question 13

Where does the ventral pathway end up? What is it responsible for?

Answer 13

it ends up in the primary auditory cortex (area A1); and it is used it ID auditory stimuli

Question 14

Where does the dorsal pathway end up? What is it responsible for?

Answer 14

in auditory corticol regions adjacent to area A1; it is involved in controlling movement related to sound

Question 15

Where is area A1 located in the cortex?

Answer 15

Heschl’s gyrus

Question 16

Where is area A2 located in the cortex and what is another named for it?

Answer 16

it is behind it and another name for it is the planum temporale

Question 17

What is significant about the size of A2 and A1 on either side of the brain?

Answer 17

for right handed people A2 is larger on the left and Heschl’s gyrus is larger on the right

Question 18

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?

Answer 18

Wernicke’s area; involved in language comprehension

Question 19

What is special about left handers regarding the size of A1 and A2?

Answer 19

15% of them are the opposite of right handers and 15% of them have bilateral speech representation

Question 20

What is the Insula and what does it do?

Answer 20

it is in the lateral fissure; it contains language and taste perception and is linked to areas with social cognition

Question 21

What is tonotopic representation and how is it represented on the basilar membrane?

Answer 21

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

Question 22

Under what level of sound does the cochlea not respond in a tonotopic manner? How does it compensate?

Answer 22

below 200hz; the apex responds differently depending on the pitch

Question 23

What are two ways to detect location?

Answer 23

Interaural time difference (ITD) and interaural intensity difference (IID)

Question 24

How does ITD function and where does it?

Answer 24

by comparing how long it takes for the sound to reach either ear; located in the medial part of the superior olivary complex

Question 25

How does the IID function?

Answer 25

the head acts as a obstacle and makes sounds quieter, the ear/brain pick up on this to locate the sound

Question 26

What is the function of Broca’s area? Where is it located?

Answer 26

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)

Question 27

What is Broca’s area and Wernicke’s area connected through?

Answer 27

arcuate fasciculus

Question 28

What is Broca’s aphasia?

Answer 28

the inability to speak fluently despite normal comprehension and intact vocal mechanisms

Question 29

What is Wernicke’s aphasia?

Answer 29

the inability to understand or produce language even with production intact

Question 30

What are 2 other regions (besides Wernicke’s and Broca’s) involved in language?

Answer 30

the dorsal areas of frontal lobes and the areas of motor and somatosensory that control the face, tongue etc.

Question 31

Where is the supplementary speech area? What happens when you stimulate it?

Answer 31

it is the dorsal surface of the left frontal lobe; it stops speech completely (Penfield)

Question 32

What does the primary (A1) auditory are respond to compared to the secondary?

Answer 32

Primary: simple bursts of noise
Secondary: syllables and more complex sounds

Question 33

Where is music production vs perception processed?

Answer 33

Production: left hemi
Perception: right hemi

Question 34

Where are pitches compared in the brain?

Answer 34

the frontal lobe

Question 35

What is amusia?

Answer 35

tone deafness

Question 36

What are 2 areas significant to the neurobiology of bird song?

Answer 36

Higher vocal control centre (HVC)
Robustus archistriatalis (RA)

Question 37

What range of sounds do bats emit?

Answer 37

12k-200k hz

Question 38

How are sensory systems organized? (3)

Answer 38

1) Hierarchically
2) Functional segregation
3) Parallel processing

Question 39

What are the 2 types of Parallel processing?

Answer 39

1) Influence conscious behavior without conscious awareness

2) Influence behavior by engaging conscious awareness

Question 40

What is a Fourier analysis?

Answer 40

a mathematical breakdown of complex waves in to component sine waves of different frequencies and amplitudes

Question 41

What are characteristics of a pure tone?

Answer 41

the are sine waves, there is a close relationship between tone and pitch, more difficult to localize

Question 42

How are hair cells depolarized? What happens?

Answer 42

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

Question 43

What kind of information do outer hair cells receive and what do they use it for?

Answer 43

input from the brain to ear; affects the stiffness of the tectorial membrane

Question 44

What part of the brain perceives differences in loudness?

Answer 44

the lateral superior olive; goes to superior collicus after (integrate with vision)

Question 45

What part of the brain perceives difference in time of arrival?

Answer 45

the medial superior olive ; goes to superior collicus after (integrate with vision)

Question 46

Where is the what pathway in the auditory cortex?

Answer 46

the prefrontal cortex

Question 47

Where is the where pathway in the auditory system?

Answer 47

posterior parietal (use both visual and auditory)

Question 48

What is endolymph? What is it rich in that allows action potential generation?

Answer 48

the fluid surrounding hair cells; it is rich in K+

Question 49

How is sound localization organized in the superior colliculi?

Answer 49

retinotopically; allows for animals like barn owls to locate mice in dark