Auditory 2

Front 1

Where is the start of the auditory neural pathway?

Back 1

Cochlear nerve - CN VIII

Front 2

Where does the cochlear nerve synapse first?

Back 2

Ventral and Dorsal Cochlear nuclei (spiral ganglia)

Front 3

Where does the Dorsal Cochlear nucleus project to?

Back 3

Via the lateral lemniscus to the InferiorColliculus

Front 4

Where does the ventral cochlear nucleus project to?

Back 4

2 places:
1. W/ DCN to lateral lemniscus to inferior colliculus
2. To SOC then to IC via LL

Front 5

Which pathway goes to the SOC?

Back 5

That for sound localization

Front 6

Which pathway goes directly to the LL/IC?

Back 6

That for pattern recognition

Front 7

Where does the inferior colliculus project to?

Back 7

Superior Geniculate Nucleus then to the Primary auditory cortex

Front 8

What is primary auditory cortex also called and where is it located?

Back 8

Heschel's gyrus in the superior temporal lobe

Front 9

What are the numbers of the primary auditory cortex?

Back 9

A1 - Brodmann's area 41

Front 10

What is the first place of binaural convergence?

Back 10

SOC in pons

Front 11

Why is it difficult to localize pathologic lesions in the auditory system?

Back 11

Because there are many crossovers - makes topography and laterality of limited use for diagnosing pathologies.

Front 12

Where exactly is auditory cortex A1 located?

Back 12

Embedded within the lateral fissure of sylvius

Front 13

Where does the primary auditory cortex project to?

Back 13

Multiple higher order cortical areas surrounding A1

Front 14

Function of Wernicke's area:

Back 14

speech interpretation - comprehension of language

Front 15

Where is Wernicke's area located?

Back 15

On the left side of the brain, in the superior temporal gyrus.

Front 16

How is the auditory cortex organised?

Back 16

Hierarchically.

Front 17

Where do lesions generally have to be to make unilateral hearing losses?

Back 17

Peripheral or in the cochlear nucleus

Front 18

What is Tonotopic Organization?

Back 18

Preservation of the topography of the peripheral receptor array within the central pathways of the auditory sytem.

Front 19

What exactly is the "receptor array" that gets preserved by higher neurons in the auditory system?

Back 19

The receptive hair cells of the cochlea that are arranged along the basilar membrane.

Front 20

important to know; where is the cochlear nucleus located?

Back 20

In the medulla

Front 21

To what tones are hair cells sensitive as you move along the basilar membrane from base to apex?

Back 21

Increasingly lower frequency tones.

Front 22

Why does the basilar membrane respond to lower freq tones at its apex?

Back 22

Because it is wider and more floppy there.

Front 23

So what is the receptive field of an auditory nerve cell?

Back 23

The region of the basilar membrane to which it is responsive.

Front 24

Characteristic frequency

Back 24

The frequency to which a cell is best responsive

Front 25

What is the frequency tuning curve?

Back 25

The curve that describes how well a cell responds to higher and lower frequencies.

Front 26

What are the axes for the frequency tuning curve?

Back 26

X - frequency
Y - spike rate
Z - intensity

Front 27

At an auditory nerve cell's characteristic frequency (X) what makes the tuning curve broaden?

Back 27

increasing intensity

Front 28

What does it mean that the tuning curve broadens?

Back 28

At a neuron's characteristic frequency as intensity increases the neuron responds to a wider range of tone.

Front 29

What do we realize by understanding that auditory nerves have characteristic frequencies?

Back 29

Nerves have receptive fields that correlate with specific regions of the basilar membrane.

Front 30

Components of a Frequency Response Curve:

Back 30

-Frequency and Spike rate change
-Intensity held constant

Front 31

What does a frequency response curve show?

Back 31

An auditory nerve's Characteristic frequency

Front 32

Components of a Tuning Curve:

Back 32

-Intensity and frequency change
-Spike rate held constant (isorate)

Front 33

What does the tuning curve show?

Back 33

How well an auditory nerve responds to different frequencies

Front 34

Components of the Intensity function curve:

Back 34

-Changing Intensity/spike rate
-Hold freq at characteristic (best)

Front 35

What does the intensity function curve show?

Back 35

That as intensity increases, the tuning curve for a neuron gets wider and the nerve responds to a wider range of tones.

Front 36

So how does an auditory nerve's response change as intensity of sound decreases?

Back 36

It becomes narrower- more sharply tuned; less likely to respond to sounds that are at different frequencies other than its own personal characteristic frequency.

Front 37

How does the tonotopic arrangement of hair cells on the basilar membrane translate to the CNS higher pathways?

Back 37

It remains; is preserved; tonotopic maps are found in most major auditory nuclei, the primary auditory cortex, and secondary auditory cortex!

Front 38

2 ways in which the auditory neural system is functionally organized:

Back 38

1. Localization pathways
2. Recognition pathways

Front 39

What pathway carries the initial localization fibers?

Back 39

Where is my OLIVE
-VCN -> superior olivary complex

Front 40

What pathway carries the initial pattern recognition fibers?

Back 40

DCN/VCN -> LL -> inf colliculus

Front 41

what is the primary auditory area A1 responsible for?

Back 41

Sorting out localization vs recognition of sound

Front 42

What is the cortex surrounding A1 responsible for?

Back 42

Higher order processing of sound

Front 43

2 important areas surrounding the primary A1 auditory cortex:
WHAT IS THE FUNCTION OF EACH?

Back 43

1. Wiernicke's area - for speech analysis (comprehension)
2. Broca's area - for speech PRODUCTION

Front 44

Result of a lesion to Wiernicke's area:

Back 44

Can't comprehend questions so can't formulate answers

Front 45

Another name for Wiernicke lesions:

Back 45

Wernicke's Aphasia

Front 46

Lesions to Broca's area result in:

Back 46

Word salad -> you can understand the question, and formulate an answer, but can't get the words out - just a jarbled mess.

Front 47

Is Wernicke's aphasia lack of speech?

Back 47

No; they can talk b/c broca's area is still ok; just don't talk because not intelligent enough to.

Front 48

How are cells higher up in the auditory complex different in terms of selectivity compared to early hair cells?

Back 48

They are more responsive - can be finicky and respond only to different complex features of sounds.

Front 49

What are the components of speech sounds?

Back 49

-Initial formant (changes over time)
-Sustained tone

Front 50

What is likely the difference between similar speech sounds?

Back 50

Only the dynamic components - initial formant

Front 51

2 factors that allow us to localize sound:

Back 51

-Binaural time delay
-Binaural intensity difference

Front 52

What causes the binaural time delay?

Back 52

The fact that our two ears are located at different places in space, so one recieves soundwaves at a time before the other.

Front 53

What causes the binaural intensity difference?

Back 53

Shadowing of the head

Front 54

Where does interpretation of interaural time and intensity differences begin?

Back 54

At the superior olivary complex - the first place of binaural convergence.

Front 55

How does the SOC allow localization of sound?

Back 55

By the fact that specific neurons within the SOC only fire when recieve SIMULTANEOUS input from 2 inputs (from each ear) - this creates a place code for location of impulse.

Front 56

What is the process of SOC cells responding to converging input from right/left pathways?

Back 56

Temporal coincidence