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Audition II > Unit 3 - Lecture 1 > Flashcards

Unit 3 - Lecture 1 Flashcards

1
Q

What are some general considerations of using animal models?

A
  1. Most knowledge is from animal models
  2. Idea: similar anatomy = similar physiology (ensure by orthologous genes)
    • Animals with similar anatomy should have similar outcomes to humans
  3. Similar functions are reported among species with similar anatomy/genetics
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2
Q

What are translational issues?

A

Can animal knowledge really be applied to humans?

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3
Q

Why is human research largely limited?

A

Human research is largely limited due to ethical reasons.

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4
Q

What animals are typically tested on?

A

Mice, monkeys are too expensive

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5
Q

What limitations exist with using animal knowledge to study humans?

A

Difficult to study human specified functions (e.g., speech, language)

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6
Q

2 classification of methods in neuroscience

A
  1. Anatomic/ morphological methods
  2. Functional methods
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7
Q

Anatomic/ morphological methods

A

On structures from gross to fine, to molecules

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8
Q

What are two types of functional methods?

A
  1. Behaviour methods (subjective)
  2. Objective methods
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9
Q

Functional methods - behaviour methods (subjective)

A
  • Observation (passive, not interference, natural, lack of control)
  • Empirical study (stimuli-responses, designed condition)
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10
Q

Functional methods - objective methods

A
  • Evoked response (Electrophysiology/optical/magnetic responses)
  • Functional imaging
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11
Q

Methods for anatomy and structures (microstructures)

A

Microstructures: dissection, staining, microscopy technologies

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12
Q

Explain how staining works

A
  • Staining to show special materials (histochemical staining,
    immunohistochemical (IHC): against proteins w/ antibodies)
  • Staining uses special chemicals and antibodies which specifically target particular proteins (this lets you observe one thin slice)
  • We want staining to only stain one particular anti body
  • 3D puts the slice information into whole structures
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13
Q

What is a very common chemical to use for staining lipids?

A

Golgi staining with silver nitrate

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14
Q

How can you track the pathway using a tracer?
- why is it not easy

A
  • It is not easy to track the pathway if the fibers are not distributed in a laminated manner (they are very thin)
  • There is a special transportation system to carry the tracer to different places from the site of injection
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15
Q

IHC to identify special protein (calpain)

A
  • Calpain increase in hair cells by noise exposure
  • Calpain is a proteinase that is activated by calcium overload in response to noise
  • In normal ear, this protein is very low level. If too much calpain, ear can be destroyed.
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16
Q

What 3 things does the nucleobase chain form?

A
  1. Genetic code
  2. Ribonucleic acid
  3. Deoxyribonucleic acid
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17
Q

What are 4 methods of molecular biology?

A
  • Expression
  • Immunohistochemistry
  • Structural studies
  • Genetic methods
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18
Q

Methods of molecular biology - expression

A
  • Expression: PCR (Polymerase chain reaction) for mRNA (transcription); Western Blotting for proteins (translation)
  • Both methdos need to remove tissue and take out cells (therefore cant observe normal structures)
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19
Q

Expression - PCR

A

Used to identify mRNA for certain protein

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20
Q

Expression - WB

A
  • Method to identify proteins
  • The protein contains charge and different sizes
  • Spread protein on certain gel, the protein will move in a field of electricity because it contains charge, smaller molecule moves faster, larger moves slowly or not at all)
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21
Q

Methods of molecular biology - Immunohistochemistry
- what does it use
- what does it allow you to observe

A
  • (IHC), with light microscopy and electron microscopy
  • Allows you to observe the molecules in the tissue where they are located (used together with dissection, staining, and microscope)
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22
Q

Methods of molecular biology - Structural studies
- What is it good for
- What is a limitation

A

Xray observation provides a good observation of 3D proteins (but there are more modern methods); limitation is that it can only observe fixed proteins, not living tissues

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23
Q

Methods of molecular biology - Genetic methods

A
  • Gene knockout/in: germ cells and conditional knockout/in somatic cells
  • Gene therapy:
    • Modulation and editing
    • siRNA
    • Stem cell transplantation
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24
Q

Genetic methods - what is gene knockout?

A
  • What is the difference between animals with and without the gene?
  • Shows the role of the gene, done to eggs so species is born without gene
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25
Q

Genetic methods - what is conditional knockout?

A

Knock out gene at a particular time

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26
Q

Genetic methods - What is gene therapy? What are two types

A
  • Decrease or increase the expression of certain genes
  • Modulation and editing
  • Stem cell transplantation
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27
Q

Gene therapy - Modulation and editing

A

Can correct particular genes for treatment (needs more research)

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28
Q

Gene therapy - Stem cell transplantation

A
  • One cell that can be used with other types of cells
  • For regeneration, some cells can be treated in vitro (can be manipulated)
  • Has been used with Parkinson’s disease
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29
Q

What are some methods suitable to human subjects? (5)

A

These are limited by invasiveness
- Behaviour studies
- Evoked potential studies
- Functional imaging
- Neural recording during surgery
- Biopsy

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30
Q

Human subject methods - Behaviour studies

A
  • Subjective
  • Give instructions then see human response
  • Non-invasive
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31
Q

Human subject methods - Evoked potential studies

A
  • Objective
  • Using gross-electrodes that are non-invasive
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32
Q

Human subject methods - Functional imagine

A
  • Can observe the functional change of the brain
  • No surgeries so not harmful
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33
Q

Human subject methods - Biopsy

A

Very popular method, shows if a particular tissue or organ has a disease

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34
Q

____ is the most important single category of functional methods in neuroscience

A

Electrophysiology

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35
Q

Electrophysiology is an ____ method that can be used in humans

A

Objective

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36
Q

What are 3 electrophysiology methods?

A
  1. In viva (done on a living organism)
  2. In vitro (done in a lab dish/test tube)
  3. Pharmacological methods (in vivo and in vitro can be used in pharmacological studies)
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37
Q

Electrophysiology - In viva

A
  • Gross electrode vs microelectrode (multi units vs single unit)
  • Near field vs far field
  • Acute vs chronic
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38
Q

Electrophysiology - In vitro

A
  • Patch clamp, whole cell clamp
  • Taking out the whole piece of the cell
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39
Q

Electrodes for recording and stimulation

A
  • At least two electrodes are needed to form a circuit for signal recoding and stimulation (the material must be conductive).
  • Two electrodes creates a loop to allow the current to pass
  • A grounding electrode provides a pathway to reduce noise
  • Isolation is needed, only tip is exposed to tissue.
  • Also dependent on the diameter (spatial selectivity)
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40
Q

Explain gross electrodes (7)

A
  • Thick, and low impedance
  • Tough
  • Poor spatial resolution
  • Far-field recording
  • Noninvasive (but can also be used invasively, but micro electrode cannot be noninvasive)
  • Responses from many neurons
  • Depends on synchronized activity
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41
Q

Explain microelectrodes (7)

A
  • Thin, high impedance (high level noise)
  • Fragile
  • Good spatial resolution
  • Invasive
  • Near-field recording (micro electrode wont work in far-field because of the low impedance that is needed for gross electrodes)
  • Single unit responses
  • Need surgery to place electrode close to the target,
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42
Q

Voltage clamp: breakthrough for action potential

A
  • Axon from Giant Squid provides the best sample for the study of voltage clamp: to study the feature of ion channels at different membrane potential (axon is 1mm which allows investigation of membrane/action potential)
  • In generation of action potential, the permeability of ion channels are changed with both time and membrane potential. In order to identify the contribution of the two factors, voltage clamp fix the membrane potential to see the change with time. (We cannot freeze time!)
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43
Q

Explain the patch clamp

A
  • Patch clamp: voltage clamp on small patch
  • Patch is small, allow the study of ion channel properties (single ion channel if patch is really small) cell is sucked into the pipe in order to tear of a small piece.
  • This allows us to understand how a particular ion channel works (in vitro study)
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44
Q

Functional Features of Individual Neurons (4)

A
  1. Functional units (neurons and circuits)
  2. Single neuron activities are the foundation of signal coding
  3. Must be recorded separately (single unit study)
  4. By microelectrodes
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45
Q

Explain single unit studies

A

Single unit study forms the foundation of neuroscience (very time consuming, need to repeat hundreds of times)

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46
Q

How are acoustic signals are coded in neural behaviour? (3)

A
  • By rate change
  • By phase locking (temporal pattern)
  • By place (tonotopic map in auditory pathway)
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47
Q

What are 2 ways to record timeline in experiment?

A
  1. Acute
  2. Chronic
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48
Q

Explain acute recording

A
  • Recording over several hours
  • Under anesthesia to make animal stabilized
    • Difficulty to hold electrode in position
  • Suitable for microelectrode recording of single neurons
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49
Q

Explain chronic recording

A
  • Using implanted electrodes
  • Can be gross and microelectrodes
  • Can be recorded from awake animals
  • Long-lasting, allow more manipulation over time
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50
Q

What are two types of single unit recording?

A
  1. Single channels
  2. Multi-channels
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51
Q

Explain single channel single unit recording

A
  • Recording activities of one neuron at a time
  • Very time consuming
  • Can be combined with dye injection to verify neurons with certain response pattern
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52
Q

Explain multi-channel single unit recording

A
  • Recoding activities of many neurons that may be connected via circuits
  • Allow exploring of neural circuits and the mechanism of signal processing
  • Can be done using acute and implantable electrodes.
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53
Q

What are 7 changes from peripheral (low level) to central station (high level, cortex)?

A
  1. Increased number of neurons (SGNs increase in the cortex)
  2. Increased versatility
  3. Slower working speed (due to synaptic delay, temporal resolution goes down)
  4. More complicated circuits, allowing detailed processing
  5. Specified processing combined with high level of integration (seen in high levels)
  6. More place coding (more functional features are related with place coding)
  7. Responses are modulated by many factors—inconsistent response to the same stimuli (sleep, attention, activities, etc)
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54
Q

Central neurons and signal processing

A
  • Relay neurons and inter neurons
  • Principle pathway and local circuits
  • Excitation and inhibition
  • Membrane property variation
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55
Q

Excitation and inhibition doesn’t exist in the ____

A

Peripheral

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56
Q

Relay neurons deliver single across different ____, inter neurons are ____

A

Stimuli (long distance), local

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57
Q

Integration of Auditory Function (what are the 3 types)

A
  • Integrate information from single unit studies
  • Example in intensity coding of auditory nerve
  • Longitude integration (along pathway: ascending and descending innervation)
  • Transverse integration: ex: integration across different frequency channels for speech coding
  • Cross-modality integration
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58
Q

EEG tests ____ brain activity

A

Spontaneous

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59
Q

Explain EEG

A
  • Electroencephalography: only largely synchronized brain rhythm can be demonstrated
  • Spontaneous brain activity
  • Can occur with or without stimulation (always brain activity happen)
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60
Q

Evoked potential is ____ to stimuli

A

Time locked

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61
Q

Explain time locking

A
  • You know when the response will happen after the stimulation
  • Due ton consistency of the time lock, the EVPs can be picked up from large noise by time averaging.
  • Detection of such small signal depends on phase/time locking
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62
Q

What is time averaging?

A
  • Time averaging = we can do thousands of sweeps so over time
  • You are averaging the response (because every sweep you get a response)
  • Noise is random at all times, the noise cancels out each sweep (this is why time averaging works)
  • Gets the peak to stand out
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63
Q

What does AER stand for?

A

Auditory evoked response

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64
Q

What are 5 ways to categorize AER?

A
  1. Labelled by latency
  2. Labelled by stimulus
  3. Labelled as exogenous or endogenous
  4. Labelled by the distance between the electrode and the generator
  5. Labelled by generator
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65
Q
  1. Labelled by latency
A
  • The most common method of categorization
  • Early, middle, and later latency
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66
Q

Explain short latency (5)

A

Shorter the latency…
- Lower the generators in ascending pathway, therefore smaller in amplitude
- Deeper in location
- Smaller in number of neurons
- More transient for synchrony required
- Less influenced by sleep

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67
Q

ABR has ____ latency, which means it is ____.

A

Short, low in the ascending pathway

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68
Q

Why is the shortest latency response the smallest amplitude? Where is it located?

A

The shortest latency response is smallest amplitude because the structure is deeply inside the brainstem (far away from the electrode that is bring used to measure)

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69
Q

Long latency = ____. Where does it directly come from?

A

Bigger amplitude (Directly from the cortex)

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70
Q

Short latency response can also be called a ____.

A

Transient response

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71
Q
  1. When something is labelled by stimulus it can either be ____ or ____.
A

Transient, sustained

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72
Q

Transient: signals vs. response

A
  • Signal: quick change of signal with time, better transient at onset and offset than other signals (transient = quick change)
  • Responses: those rely on the transient feature of signals, e.g., CAP in EcochG, ABR etc.
  • Example: click evoked ABR (click is the stimuli which is a transient signal, ABR is also transient)
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73
Q

Why do we need transient?

A
  • Smaller amplitude due to deeper location and smaller amount of neurons
    • Larger difference between electrode and target, therefore we need the neurons working together
  • Short duration resulting in stronger requirement for synchronization
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74
Q

____ is the most transient auditory evoked response

A

ABR

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75
Q

Only see transient signal at the ____ and ____ of tone burst. Therefore ____ is the most transient.

A

onset, offset, click

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76
Q

A transient ____ is needed to produce a transient ____.

A

Signal, response

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77
Q

Why does ABR require a transient stimulus?

A
  1. Early response generated from deeper structure (spatial attenuation)
  2. Early response generated from smaller number of neurons.
  3. Action potential of early response has shorter duration, therefore require better synchronization.
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78
Q

Transient vs frequency selectivity

A
  • Transient: signal with short duration, sharp on and off
  • Abrupt on and off causes frequency splattering, therefore poor frequency selectivity
  • The more transient the stimulus is, the less frequency selective you will have (a very quick onset and offset means there is more chance for splattering)
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79
Q

What is a method for compromising splattering?

A

Short duration tone with time windows

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80
Q

Short duration means ____.

A

Broad band

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81
Q

____ are more frequency selective than a click because they ____.

A

Tone bursts, don’t splatter as much

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82
Q

Explain a click
- what is it (range)
- what is below
- where is synchronization best

A
  • Broad spectrum signal, further limited by transducer (speaker or earphone) but still broad, up limit: ~4-5 kHz
  • Evoke below 5 kHz, spread at high intensity
  • Synchronization better in high F at basal end due to high speed of traveling wave
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83
Q

Why is a click a broadband signal?

A
  • A click is a broadband signal because it is so short in duration and quickly changes with time
  • Therefore, a click is going to have poor frequency selectivity
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84
Q

Explain a click by a 0.1ms pulse
- what is the half power point
- what are the main contributors of ABR?
- what intensity is a cochlear excited at below 5 kHz?

A
  • 0.1 ms pulse is the click that we use (the cut off frequency is at 5 kHz = half power point)
  • Between 0 – 5 is the main contributors of the ABR (3kHz – 5 Khz) = better synchronization
  • At low to moderate intensity, cochlea is excited below 5kHz
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85
Q

Major contributor to ABR is ____ region

A

2-5 kHz

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86
Q

Using clicks for ABR will give you the best ____.

A

Frequency region

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87
Q

Sustained response or steady-state response

A
  • Example: 40 Hz response
  • Repeated click presented at a rate of 40 Hz (doesn’t depend on transient, but periodicity)
  • Or any signal with periodicity of 40 Hz, such as AM
  • You can have a signal with a frequency of 4000 Hz, but you can amplitude modulate it so the periodicity is 40 Hz
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88
Q

What are event-related potentials?

A

Related to the circumstances under which they are elicited rather than to the physical properties of the signals

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89
Q

What is ASSR?
- what frequencies and where is the generator

A
  • Auditory steady state response
  • ASSR at higher frequency: generator moves to brainstem
  • ASSR = a clinical method to record sustained response
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90
Q

Why does ERP happen?

A

It is not entirely clear, it may be related to internal brain activities

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91
Q

steady-state potential is not a response to the ____ of the signal, but to ____.

A

transient feature, periodicity

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92
Q

What is the advantage for a 40 Hz event related response?

A

Big amplitude, better frequency selectivity (due to long duration of stimuli)

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93
Q

What is the disadvantage for a 40 Hz event related response?

A
  • Unknown generator, not reliable in children, influenced by sleep (consciousness)
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94
Q

How 40 Hz ASR added up?

A

If stimuli have periodicity of 40 Hz (25 ms interval), the peaks will add up (the stimuli will match the interval and enhance the signal)

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95
Q

ASSR signals
- carriers
- what does it tell us
- what produces periodicity
- signal energy

A
  • Carriers: could be tone, narrow/wide band noise
  • ASSR tell the function of region of carrier frequency (CF)
  • Amplitude modulation to produce periodicity: modulation frequency (MF)
  • Signal energy: mainly at CF, two sidebands: CF+/-MF
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96
Q

For ASSR use a long-lasting signal with a periodicity of ____

A

40 Hz

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97
Q

The carrier could be 4000 Hz or anything, but need to modulate it at ____ for it to work

A

40 Hz

98
Q

Long-lasting signal create better ____.

A

Frequency selectivity

99
Q

ASSR is able to tell the function of the frequency region of the ____.

A

Carrier frequency

100
Q

Signal energy is mainly distributed around the ____

A

Carrier frequency (two side bands is the modulation frequency around the carrier frequency)

101
Q

What is the source of a 40 Hz tone come from?

A

Midbrain and above

102
Q

What is the source of an 80 Hz tone come from?

A

Brainstem

103
Q

Explain the source of higher frequencies (3)

A
  • More from peripheral (lower level)
  • Smaller amplitude
  • Less influenced by sleep
104
Q

Explain the modulation frequency
- what is it
- what does it impact
- what if our modulation frequency is high

A
  • The modulation frequency is the rate at which the amplitude of the carrier tone fluctuates over time (the 40Hz tone)
  • Where the steady state responses are generated depends on the modulated frequency
  • The higher the modulation frequency, the more contribution from the auditory peripheral (but less neurons here for get a smaller amplitude); so it’s a tradeoff
105
Q

Need to be awake in ____ so difficult for infants

A

ASSR

106
Q
  1. Labelled as Exogenous or endogenous
    - what processing does each use
    - what are examples of each
A

Exogenous
- Depend on the physical features of the stimulus (SLR, MLR, N1-P2, LLR)
- Only bottom up processing

Endogeneous
- Perceptual; depends on the context no physical features (P300 and other cognitive components)
- Top down and bottom up processing

107
Q

What is P300?

A

Occurs 300 seconds after the stimulus

108
Q

Mismatch negativity (MMN) - 6

A
  • Event Related Potential, but not cognitive
  • Elicited by discriminable changes in signal
  • No attention is needed
  • But based upon memory train established by preceding (standard) stimulus
  • Odd-ball paradigm
  • Not endogenous, it belongs to middle latency
109
Q

What is the oddball paradigm?
- what does it measure
- explain the components

A
  • A way to measure mismatch negativity (but also used with endogenous)
  • 1st stimuli is regular, common, and occurs more frequently
  • 2nd stimuli is rare, and occurs less frequently
  • Overall ration is 7:1 (S1 appears more often than S2)
110
Q

Explain the oddball paradigm for mismatch negativity
- what is the process
- what can you determine from this

A
  • Standard: 1000 Hz
  • Odd: 1000 Hz +
  • When the difference between the standard f and odd f is small, the response is largely overlapped, hardly a difference (not picking up odd stimulus)
  • As the odd stimulus goes away from the standard, the responses are different (mismatch negativety)
  • Not endogenous (so don’t need to be paying attention, your brain just notices the different response)
  • Can determined frequency discrimination threshold (how small does the mismatch negativety have to be to notice a difference)
111
Q

What is the difference between ignoring and attending to the stimuli?
- what are 3 components of endogenous
- when do you see P300

A
  • Endogenous response: longer latency, require attention, related to perception
  • P3 does not exist in response to the frequent signal
  • We don’t see the P3 signal when ignoring the signal
  • They actually need to pay attention (if they weren’t paying attention wouldn’t see the P300)
112
Q

Explain the oddball paradigm using words

A
  • Stimuli: sentences with different endings.
  • Normal ending: frequent stimuli
  • Illogical ending: odd stimuli (R stimulus)
  • Perception: understanding the sentences.
  • This shows the importance of context
  • The weirder that it gets, the response gets bigger (your brain is expecting one thing and you receive something else)
113
Q
  1. Labelled by the distance between the electrode and the generator
    - explain both
A

Near-field
- Electrodes close to generator
- Used when monitoring: (1) in surgery room, (2) in combination with far-field recording for localization of generator, (3) behaviour of a single neuron

Far-field
- Electrodes far away from generator
- Used as non-invasive method

114
Q

In most cases, clinical application is ____

A

Far-field

115
Q

____ is typically invasive so not commonly used in clinic

A

Near-field

116
Q
  1. Labelled by generator
    - ECochG
    - ABR
    - Cortical response/potentials
A

ECochG: response from cochlea
ABR: auditory brainstem response
Cortical responses/potentials: from cortex (P300)

117
Q

Neural activity and electric field: 2-source and 1-sink in current

A
  • Neurons generate APs which propagate along axons
  • Potential difference changes with distance
  • The voltage difference goes down with distance
  • When excitation happens, it establishes electrodes with the positive side and negative side
  • Electric field can be mimicked by 2 poles (one positive and one negative)
118
Q

Explain the dipole electric field in volume conductor

A
  • The dashed lines and solid lines are orthogonal to each other (the voltage is the same along any line)
  • This is the electric field the neurons are creating with two poles
  • The current between the 2 poles is conducted in volume conductors (not line conductors like daily life)
  • Current can go across any dashed line between the two poles
  • In order to record the neruons electrical field we have to place the electrode in the same iso-potential line as the two poles (otherwise you wont be able to record the potentials)
  • This is why in ABR electrodes are places in a particular location coming from this idea
119
Q

Explain how amplitude changes with distance (in regards to near field and far field)

A
  • Near field: larger amplitude, larger change if distance change
  • Far field: smaller amplitude, small change with distance
  • If you move electrode across x-axis will get a big amplitude of signal when close to the generator
  • Near vs far field looks at amplitude and change with distance
120
Q

Effect of electrode position

A
  • Far field recording yields poor spatial selectivity and smaller amplitude
  • Near field recording we see two peaks (better spatial selectivity)
121
Q

Effect of neural structure (open field vs. closed field)

A

Open field
- Structures are arranged in a regulated orientation
- The response can be spatially added up
- Can use far-field

Closed field
- Arranged randomly
- Can’t be easily added up
- Can’t measure using far-field

122
Q

Neural activities in closed field cannot be recorded in ____

A

Far-field

123
Q

Electrocochleography (ECochG)
- when does it mature
- what does it contain

A
  • First group of AER studied
  • Mature immediately after birth (in humans, in mice takes 2 weeks)
  • Contain receptor potentials from hair cells
    • SP (summating potential), CM (cochlear microphonics)
    • Neural response—CAP (compound action potentials)
124
Q

ECochG by clicks - How can we get rid of CM and show SP?

A
  • SP is not shown because of filter setting. Eliminating CM by averaging with alternating polarity
  • To get rid of the CM, do alternating averaging
  • SP is a direct current potential (it can be seen by a click, but more easily with tone bursts)
125
Q

ECochG by tone bursts
1. N1 N2 = ____
2. CAP and CM are ____ because they are alternating in phase
3. CM and SP come from hair cells, both are ____
4. CAP = happens at ____

A
  1. CAP
  2. Alternating current (AC)
  3. Receptor potentials
  4. Onset and offset (because APs are synchronized)
126
Q

Basic feature of CM (6)
- what does it mimic
- does it have latency
- what is it generated by
- what does it reflect
- is it useful
- can it be contaminated

A
  • Mimic sound wave—can be eliminated by alternating averaging (in alternating average, signal is presented in opposite polarity in every following stimulation, adding the response will cancel the CM)
  • No latency (except the time for sound travels from speaker to cochlea)
  • Generated mainly by OHCs
  • Reflect the function of MET
  • Least useful in clinic
  • Easily contaminated by electro-magnetic artifacts from transducer
127
Q

As soon as the sound stimulates the HCs, ____ happens

A

CM

128
Q

CM can contaminate the response, so need to get rid of it by ____

A

Alternating the average (flipping polarity)

129
Q

How to identify artifacts in CM testing? (4)

A
  • Look at the latency (CM only has latency from speaker into the cochlea, but the artifact would have no latency at all)
  • Artifacts increases linearly with sound level, but CM saturated at high sound level
  • Artifacts have no time delay
  • Close sound pathway will reduce CM but not artifacts
130
Q

Basic feature of SP
- what is it
- what is it contributed from
- what doest it vary in (5)
- how is it recorded

A
  • Appears as baseline shift in response to sound (how the whole response has moved down)
  • Contributed from IHCs, OHCs and probably neurons (multiple generators)
  • Varied in amplitude, polarity with sound intensity, level and duration, as well as electrode location (most variable response)
  • Recorded from extracochlear electrode, SP is likely to be negative (similar polarity as CAP), but can also be positive if stimulation frequency is very high.
131
Q

Basic features of CAP
- where are peaks from
- where does someone think N2 is from
- how is it recorded
- what is it dominated by

A
  • N1 from dendrites of SGNs, latency ~1 ms (first negative peak)
  • N2 from axons of SGNs, latency ~ 2 ms (second negative peak)
    • Someone thinks that N2 from CN neurons.
  • Recorded extrocochlearly, CAP is dominated by SGNs of basal turn—due to better synchrony
  • CAP is dominated by ANFs with high SR.
132
Q

If we record outside of the cochlea, it is dominated by SGNs of the ____

A

Basal turn (better synchronization)

133
Q

What can you determine by looking at the SP/CAP ratio? (4)

A
  • Meniere’s disease/endolymphatic hydrops, by measuring SP/CAP ratio
  • Identify wave I in ABR
  • Monitoring hearing function in surgery
  • Diagnosis of auditory neuropathy
134
Q

Need synchrony to see CAP, and no synchrony can mean ____

A

Auditory neuropathy

135
Q

ABR (Auditory Brainstem Response) (6)
- what response
- what latency
- sleep?
- when developed
- generators
- what is it used for?

A
  • Transient responses—require higher level of synchronization
  • Short latencies (<12 ms)
  • Not influenced by sleep
  • Quick and well documented after-birth development
  • Clear generators
  • Main form of hearing testing for babies that refer on their hearing screening
136
Q

Combination of near-field and far-field recording to identify generators for ABR
- longest pathway
- shortest pathway

A
  • Shortest pathway: SGN-CN-IC
  • Longest pathway: SGN-CN-MNTB-SOC-LL-IC
  • Therefore, one peak may result from multiple nuclei.
  • Far field first to get wave 1, 2, 3, 4, 5 (so you know the times these happen and with the near field recording you can see what records what)
137
Q

Identification of the Neural Generators - 3 methods

A

Methods
1. Simultaneous near-field and far-field recording
2. Lesion experiment
3. Three dimensional recording

As you get up into the brainstem (wave 3, 4, 5 is more complex)
- Wave 1 = auditory nerve
- Wave 2 = cochlear nucleus
- The others are more complex

138
Q

What is a lesion experiment?

A

Lesion a certain generator to see which peak disappears

139
Q

What is 3 dimensional recording?

A

Can see how the response changes by different placement of electrodes

140
Q

Certain wave peak may have ____ because the complexity of auditory pathway

A

Multiple generators

141
Q

AMLR—Auditory Middle Latency Response (6)
- what is the latency
- generators
- when is it developed
- is it contaminated
- sleep?
- what does it have better?

A
  • Latencies: 12-50 ms
  • Generators: not clear/multiple sources for each peak (less clear cause higher up in the pathway)
  • Later development. not available at birth (need 14 mo. to see clearly, not mature until 7yrs)
  • Easily contaminated by muscle movement (a tense neck can ruin your middle latency response)
  • Influenced by sleep (be awake)
  • Better frequency selectivity—steady state response
142
Q

Any response longer than a short latency response is ____

A

Influenced by sleep

143
Q

ALR—Auditory Later Response (6)
- what is the latency
- what is it made up of
- sleep
- generators
- amplitude size
- what does it need

A
  • Latencies: 50-250 ms (long latency response)
  • Multiple components
  • Influenced by sleep
  • Unclear generators
  • Big amplitude (more amount of neurons)
  • But need longer stimulus interval
144
Q

Application of AER in Auditory Assessment (5) - what do you need for long latency tests in humans

A
  • Long-latency response provides better frequency selectivity
  • Need cooperation from subject
  • Only for mature subjects
  • Big variation (as compared to small latency)
  • ABR is still used most, but need improvement
145
Q

What is not an AER?

A

EEG (you don’t need a stimulus)

146
Q

Categorization of imaging methods (4)

A

CT: computerized tomography (based upon X-ray)
PET: positron emission tomography (on radiation)
MRI/fMRI: magnetic resonant tomography
Multiphoton Microscopy

147
Q

What imaging techniques are morphological?

A

CT and MRI

148
Q

What imaging techniques are functional?

A

PET and fMRI

149
Q

Is multiphoton microscopy morphological or functional?

A

Both

150
Q

What imaging techniques are being used in clinics? What one is still being researched?

A

CT, PET, and MRI/fMRI are used in clinics
Multiphoton microscopy is still being researched

151
Q

Explain X-ray and radiography

A
  • Radio beam and absorption (Different tissue has different absorption rate)
  • Standard x-ray: source-subject-film
152
Q

What is one step ahead of x-ray? explain what CT uses

A
  • CT scan is one step ahead of x-ray (it is more focused and looks at single layers at a time, less broad)
  • CT: laminography based upon rotation of source and detector, laminography at multiple planes produces polytomography
153
Q

Explain CT scan (6)
- what does it do
- what are images shown by
- how is the image reconstructed
- what has low contrast
- what is it best for

A
  • Scanning with focused beam on thin layer of tissue
  • Show image according to absorption
  • Reconstruction by computer software
  • High spatial resolution
  • Contrast across different soft tissue is low (as compared to MRI)
  • Best for bony structure
154
Q

Explain how a CT scan is set up

A
  • A collimator is a device that narrows a beam of particles or waves.
  • The source and detector both rotate around the body (one layer at a time before moving to the next layer)
155
Q

Contrast-Enhancement in X-ray and CT: why is it done? what are 3 methods?

A

Contrast-enhancement is done to increase absorption and to show soft tissues with CT better.
3 methods are
- Inject substance into body space and blood
- Iodinated compounds
- Air injection: pneuomoencephalography

156
Q

Acoustic neuroma is shown in CT scan by ____

A

Enhancer

157
Q

Explain MRI
- how are atoms aligned
- how are atoms excited
- what do different tissues show
- what is MRI better for

A
  • Atoms are aligned by external magnetic field
  • And excited by radio impulse at Larmor fre to high energy status
  • Different tissue, different signals–>images
  • Better resolution for soft tissues
158
Q

Explain what the protons are doing at the start of an MRI (4)

A
  • Each atom contains a small magnetic field
  • The magnetic field in each atom is randomized in term of direction, therefore you will not see the magnetic force because they cancel each other spatially
  • An MRI applies a strong magnetic field, which pushes the individual atoms into the same direction (alignment)
  • When alignment happens, the magnetic field can be formed
159
Q

Explain the radio frequency used in MRI

A
  • A signal of radio frequency (RF) at the Larmor Frequency of each nucleus (or the natural frequency) pushes the proton in the nucleus out of alignment: high energy status
  • The energy of driving magnetic field is absorbed at Larmor frequency.
  • The RF is used in a broad frequency region (contains many different frequencies)
  • The Larmor frequency is the natural frequency of each nuclei
  • Use a detector to generate the image
160
Q

Explain how the protons return from high energy to low energy status
- what happens with T1 and T2

A
  • From high energy status returning to low energy one accomplished with an emission of RF energy (at Larmor frequency)
  • Recovery to alignment and the status of losing phase (related to T1 and T2): T1: return to aliment, T2: return to random status without external magnetic field
161
Q

Three status of atoms in magnetic fields (MRI)

A
  • Random (low energy) - natural
  • Alignment (forced in phase)
  • Irritated (high-energy status)
162
Q

In MRI, the emission is picked up by detector and provide information about ____.

A

Structure

163
Q

MRI Image formation
- What is the release of RF specific too?
- How is the RF detected?
- What is the amplitude modulated by?
- How is the image created?

A
  • Release of RF is tissue (nucleus) specific
  • RF detected by receiving coils
  • Amplitude mapped by Fourier transformation
  • Image created by using the signal
    • Material jumps back to low energy status to produce images
164
Q

MRI T1 and T2-weighted image

A
  • T1: longitudinal (spin-lattice) relaxation time for proton to gain realignment (from high energy status)
  • T2: transverse (spin-to-spin) relaxation time for proton to equilibrium value.
  • Time durations for T1 and T2 changes with different tissues
  • T1>T2 (T2 relaxation is quicker than T1) – T1 is longer than T2 for most tissues (for water both are the same)
  • Different structures prefer different images (T1 vs T2)
  • In T2 image: water is bright, soft-tissue with fat is dark–Good for showing pathology because most lesions are having water
165
Q

For temporal resolution use a ____ weighted image

A

T2

166
Q

What is the main difference between T1 and T2?

A

T2 relaxation is quicker

167
Q

What does water look like in T1 and T2?

A

In T1: water is dark
In T2: water is light

168
Q

Explain fMRI
- whats it related too?
- what is a common method?
- what does increased brain activity have?

A
  • Related to metabolism and blood flow
  • Common method: blood oxygenation level-dependent (BOLD) contrast fMRI
  • Increase brain activity—increase deoxyhemoglobin—increase blood flow (2-6 second later), surplus
  • Deoxyhemoglobin has greater magnetic susceptibility
  • MRI signal represents the ratio which indicates brain activity
  • T2-weighted image for quicker imaging (better temporal resolution)
169
Q

fMRI - image related to hearing task

A
  • Limitation by the huge scanner noise (>100dB SPL) difficult to get
  • Limited by temporal resolution
  • Methods to reduce the impact of background noise
  • Whatever signal you get will partially come from noise
170
Q

Resting status fMRI (rs-fMRI)

A
  • Look for the low frequency vibration of BOLD
  • Calculate correlation across different regions
  • Strong correlation represents strong connectivity (functional connectivity)
171
Q

One ear stimulation with fMRI

A

When one ear is stimulated, both sides of the brain are stimulated (shown in PET scan)

172
Q

Explain PET

A

Radioactive material is injected into blood, stronger signal from area with high blood flow (the brain region that is more active will take more blood supply)

173
Q

PET images for speech perception: strong in ____ side of brain

A

Left

174
Q

Functional images - the brain area with stronger activity/larger metabolic rate will show ____ signal

A

Stronger

175
Q

Functional methods depend upon areas that are ____ and ____

A

Oxygenated, deoxygenated

176
Q

What does magnetoencephalography measure?

A

Measures the magnetic field produced by electrophysiological responses

177
Q

What are 2 advantages of magnetoencephalography?

A
  • High time resolution (comparable to EEG, > MRI/PET/CT
  • Better spatial resolution than EEG/EP
178
Q

Effective ionizing radiation for a PET test is ____ per year.

A

14 micro-Sievert (mSv)

179
Q

Explain fluorescence microscopy
- what shows the different molecules
- what is the visible wave length
- what absorbs the light
- what is the emitted light different from?
- what 2 things separates the emitted light?

A
  • Fluorescent dyes made highly selective to a molecule of interest (DNR/RNA, protein, lipid), diff. colors for different molecules
  • Illuminated by light of a specific wavelength, in visible wavelengths (390-700 nm)
  • Absorption of the light by fluorophores, jumping to high-energy state, emitting light when returning back
  • The emitted light is different from that of illumination
  • The emitted light is separated from the illumination by emission filter and dichroic beamsplitter
180
Q

Explain laser confocal scanning microscopy (LCSM) or Confocal microscopy
- why do wide-field fluorescence microscopes have poor resolution?
- how does LCSM work?
- what does it show a better image than?

A
  • Wide-field fluorescence microscopes has poor resolution due to the emitted light from unfocused background
  • In LCSM, only one point is illuminated at a time, and pinhole is used to block further from the unwanted area, to increase resolution
  • Shows a better image than fluorescence microscopy, but it is still not good enough
181
Q

Limitations of LCSM and advantage

A
  • Visible light is largely scattered and absorbed before it reach a deep target
  • Limited the depth upon which the observation can be done.
  • Limited the use in vivo.
  • Advantage of 2 photon
    • Allows visualization of living tissue at depths
182
Q

How 2-photon imaging work?
- what does photon absorption do?
- what light is used?
- how close are they applied to each other?
- what is that wave length?
- how is energy released?

A
  • Photon absorptions excite a molecule to higher energy state
  • Use infrared light (light that is longer than the wavelength that is visible to us) to reduce absorption and scattering
  • The 2-photons are applied within 1 femtosecond of each other
  • In this way, the two photons, each with wavelength of 400-500 nm, make the wavelength of excitation to be 800-1000 nm (infrared).
  • However, only one photon will release energy at a time, so to present visible light
  • Better focus (no out-of-focus light)
183
Q

Single photon images show ____ that are emitted
Multiphoton emits ____ (can be used in living tissue)

A

large areas, one dot at a time

184
Q

Life imaging of brain

A
  • This is a good tool to investigate brain plasticity (to see how particular material changes over time)
  • Used on animals, not humans
185
Q

Methods of Psychological Evaluation (6)

A

These are methods to determine hearing threshold (sensitivity limen) – softest sounds they can hear, or smallest gap between two sounds they can discriminate…
- Classical methods of limit
- Method of constant stimuli
- Method of adjustment
- Adaptive procedure and derived
- Two-interval forced choice
- Scales of measurement

186
Q

Method of Limit or Yes-No Method (for threshold)

A
  • Tester (audiologist) changes stimulus level in discrete steps
  • Testee responds: yes/no (or no response)
  • Descending series: started well aboce the estimated threshold; check reversal response
  • Ascending series: starts well below estimated threshold; check seversal in response
  • Calculating averaged of reversals as threshold
  • Can be used for both absolute threshold and differentiation threshold
187
Q

How is the method of limit different from finding hearing threshold in clinic?

A
  • The tester is turning down the stimulus level in 2 dB steps
  • Much more accurate
188
Q

Method of limit for Differential Limen

A
  • Compare between two sounds (is sound 1 or sound 2 louder)
  • There will be two transition points (louder to equal, and if the first sound is softer than the second sound)
  • Between the 2 transition points the level difference is the ability of discrimination
  • To determine the differential limen do averaging of the two transition points
  • The larger the difference between the two transition points, discrimination is poor
    • 58-53 = 5 which is their differential limen
    • They can discriminate within 5 dB (anything between there the subject cant tell there is a difference)
189
Q

What are 2 limitations or bias due to guessing in the method of limit?

A

Anticipation – the subject predicts change might happen.
- Lower (better) ascending threshold; anticipate the stimulus
- Higher (poorer) descending threshold; anticipates not hearing it

Habituation – no change in response until larger change in stimuli
- Ascending: does not change response from no to yes until threshold exceeds a few trials
- Descending: continues to respond yes after the sound is inaudible

Time consuming because we are trying to be very accurate

190
Q

What does anticipation result in?

A

Results in a lower/better ascending threshold and a higher descending threshold

191
Q

What technique is used to prevent guessing?
- why does it prevent guessing

A
  • Method of constant stimuli
  • Order is random, so subject has no way to guess what will be the next stimuli (could be much louder or much weaker)
  • Collect response across many trials to see how many yes responses were presented
192
Q

Explain how the method of constant stimuli works?

A
  • Using a fixed set of stimuli (10 or 20 levels)
  • The whole set of stimuli is presented in each trial
  • Within each trial, the stimuli are presented in random order
  • Calculate % correct across many trials
  • Draw curve to determine limen (50% response level)
193
Q

Method of constant stimuli example

A

The whole set consist of 8 levels, totally 50 trials—each stimulus 50 times

194
Q

Step size and accurate estimation

A

The smaller the steps, the more accurate the estimation

195
Q

Explain how the method of constant stimulation can be used for differential limen

A
  • They are playing the second tone and discriminating which is louder
  • Marking how often they say the second tone is louder or quieter
  • You can get 50% by guessing, so need to look at differential limen
  • 75% determines the differential limen because you can get 50% by guessing
196
Q

Explain why we have to use 75% correct as the threshold for differential limen

A
  • 50% can be obtained by chance (guessing).
  • DL is determined at a performance certain value above chance
  • DL usually set up at 75% “louder” responses-certain % above chance. – this is used as criteria for threshold
  • DL (%) varies: to be more aggressive or conservative
197
Q

Method of Adjustment
- what is it
- what is the bias

A
  • Testee controls the signal change (converting point)
  • Stimulus is changed continuously not in discrete steps
  • Used for testing absolute thresholds and differential limen
  • Control dial must be unlabelled to avoid bias
  • Bias: perseveration of response/persistence of stimulus
198
Q

Explain perseveration of response

A

Persistence of the stimulus means that a lower threshold is obtained on a descending run because the subject continues to turn the level
down below threshold as though the sound were still audible

In an ascending trial, the absence of audibility persists so that the subject keeps turning the level up until the true threshold is passed by some amount, which has the opposite effect of raising the measured threshold level.

199
Q

Adaptive Procedure
- what does it depend on
- what do you do
- why is it more efficient

A
  • Stimulus presented depends on previous response
  • Make changes around threshold (target), not far away
  • More efficient method because (1) close to target (2) no need for estimation of target (3) adjustable step size leads to more precision
  • Many alternative procedures in practice: e.g. modified method of limit by adaptive procedure
200
Q

What method does the adaptive procedure use?

A
  • Up-Down or staircase method
  • Closing in on the threshold
201
Q

Parameter estimation by sequential testing (PEST)

A
  • Adaptive changes in both direction and step size
  • As you get closer to the threshold the step sizes are getting smaller
  • More efficient (no need for estimation of target, don’t need to have an idea of what their threshold is)
202
Q

Method of Tracking
- what is it an example of?
- what does the subject do?

A
  • Example of the adaptive method
  • Subject controls the stimuli, but only the direction (ascending or descending)
    • If detected turn it down, if not turn it up
  • Fixed rate of change
  • Bekesy audiometry (frequency also changes in a fixed rate (not control by subject; subject only controls levels)
203
Q

The principle of adaptive method is that sound level fluctuates around ____

A

Threshold

204
Q

Bekesy tracking
- what is changed
- how does it work
- what are the trials

A
  • Both frequency and intensity are changed.
  • Testee controls only the direction of intensity change (not freq)
  • When the sound is audible, tune it down, not audible, tune it up
  • Frequency is changed at a fixed rate
  • Two different trials with (1) continuous tone, (2) pulsed tone
  • Diagnosis mainly based upon the difference between the two trials
205
Q

5 types of performance from bekesy tracking

A
  • Type I: normal or CHL (no separation between tones)
  • Type II: cochlear HL/SNHL (separation of the two curves at higher frequencies)
  • Type III: retrocochlear (much larger separation, auditory neuropathy, the continuous tone drops off because the person is experiencing auditory fatigue)
  • Type IV: retro/cochlear (retrocochlear and cochlear pathologies, separation across whole frequency range, but more cochlear loss)
  • Type V: pulsed threshold higher than continuous one, seen in non-organic HL
206
Q

Two Alternative/Interval Forced (TAFC) Choice: Method for Difference Limens

A
  • Compare standard tone and probe tone or other alternative comparison (e.g., one interval has noise, the other has noise + signal)
  • Threshold must be 75% or higher (because can get 50% by guessing)
  • Response modification (variation/size of signal difference between two intervals can be changed)
  • Calculate mean
  • Variations in procedure regarding this method
207
Q

What the % threshold would be if 3IFC

A

Present 3 intervals and only one will contain the target sound (choose which one has the tone)
- If is 3 intervals forced choice
- The % correctness from guessing is 33%
- The criterion for threshold can be 50%.

208
Q

What are the 4 scales of measurement?

A
  • Nominal scales
  • Ordinal scales
  • Interval scale
  • Ratio scales
209
Q

What is a nominal scale?

A
  • The least restrictive
  • Assign observations to groups
  • Ex: male-female, normal-hearing impaired
  • No ordering
210
Q

What is an ordinal scale?

A
  • Rank order of observations (1st, 2nd, etc)
  • Does not define the size of difference between the categories
211
Q

What is an interval scale?

A
  • Specify order and distance
  • Ordered metric scale (ruler)
212
Q

What is a ratio scale?

A
  • Define distance in ratio instead of absolute unit
  • Understand “true zero point” - not actually zero, otherwise the ratio will be indefinitely large (sound level)
  • Highest level of scaling (most restrictive)
213
Q

Direct Scaling (5)

A

Ratio
- Ratio estimation (how many times louder)
- Ratio production (make the sound 2 times louder)
Magnitude
- Magnitude estimation (assign a number to a giving sound)
- Magnitude production (match sound to a given number)
Cross-Modality Matching

214
Q

What is the modulus?

A
  • This is the estimation of magnitude (with reference to other stimuli)
  • Present at different levels and ask subject how they would compare that sound to the modulus
  • A modulus us used so subjects have something to compare
  • Trying to quantify how loud something is
  • First subject hears sound (modulus) –> then we tell the subject we call this a number 10
  • Then present tone at a different level and get them to give a number to that and how it related to the modulus
215
Q

Can the modulus be removed?

A
  • Yes, because it is relative
  • Modulus can be removed: absolute magnitude estimation (AME)
216
Q

Magnitude Production
- how to assign numbers (bias)

A
  • Reverse of magnitude estimation
    • Subject makes sound level based upon the number that is given
    • Can be done with and without modulus (absolute magnitude production (AMP)
  • Subject bias: tend not to assign extreme values in magnitude estimation, but to make extreme level adjustments in magnitude production
    • A number is given (number 9), and the subject would adjust the sound a produce a sound that is equal to that number
217
Q

Estimation/production without reference to modulus and other stimuli
- where is the bias more true

A

Bias is especially true at lower sound levels (the separation is close at higher sound levels, but are farther apart at lower sound levels)

218
Q

What is PMB?

A
  • Bias and balancing procedure (PMB—psychological magnitude balance)
  • How you balance the bias, accurate representation of a persons loudness sensation
219
Q

Sensitivity vs response proclivity

A

Sensitivity—real threshold
Proclivity—response bias or uncertainty

220
Q

Proclivity in Psychoacoustic Evaluation - method of limit

A
  • Anticipation
  • Habituation
221
Q

Proclivity in Psychoacoustic Evaluation - method of adjustment

A

Persistence of the stimulus, or perseveration of the response

222
Q

Yes and No: four possible outcomes

A

Hit = there is a signal and the subject detects
Correct rejection = no signal and subject didn’t hear
Miss = there is a signal but subject fails to detect
False alarm = no signal but subject says there is one

223
Q

Correction for chance success

A

p(hit)corrected = p(hit) - p (false alarm) / 1 - p (false alarm)

224
Q

If p(hit) = 0.78 and p(false alarm) = 0.17, what is the p(hit)corrected?

A

0.735

225
Q

A pass is considered…

A

Not having the disease

226
Q

A fail is considered…

A

Having the disease (it is bad to have the disease)

227
Q

True failed
False pass
False failed
True pass

A
  • Hit = true failed (TF); subject has the disease and they really do
  • Miss = false pass (FP); subject has the disease but results don’t show it
  • False alarm = false failed (FF); test shows they have the disease, but they actually don’t
  • Correct rejection = true pass (TP); subject is healthy and the test doesn’t show any problem
228
Q

A true fail and a false pass means you are ____.

A

Impared

229
Q

A false fail and a true pass means you are ____.

A

Normal/healthy

230
Q

Sensitivity and specificity

A

Sensitivity = TF/[TF+FP] (% impaired that hit)
- The ability to detect a positive result

Specificity = TP/[TP+FF] (% of normal that pass)
- The ability to detect a negative result

231
Q

A high sensitivity is critical for a ____.

A

Screening tool

232
Q

A high specificity is critical for terminal ____ tool

A

Diagnosis

233
Q

What type of test is NBHS?

A

NBHS is highly sensitive because you don’t want to miss anyone that has hearing loss (more false positives possible) it is screening, then do a diagnostic test to confirm

234
Q

Assumptions of Theory of signal detection (TSD)

A
  • Noise exists: external and internal
  • Function changes
  • Decision: noise alone (N) or signal-plus-noise (SN)
    • Decision axis
    • Or magnitude of sensory activation
    • Probability
235
Q

How do we make decisions?
- what does a large separation between N and SN mean?
- what does d’ represent?
- what does it mean if the curves are largely overlapped?
- what does it mean if there is a large separation between curves?

A
  • Larger the separation between N and SN, and the smaller the σ, the bigger the d’—the measure of sensitivity
  • The distance between the response of noise and noise + s are represented by d’
  • B shows the cruves largely overlapped, it is harder to make a decision (d’ is smaller)
  • A is showing a larger separation so it is easier to make a decision
236
Q

Performance changes with ____ as well as noise

A

Signal energy

237
Q

Making an internal decision
- 2 ways of bias

A

Biased by:
(1) Subject knowledge about the chance of signal
(2) Award of correct response (consequence of making different mistakes)

238
Q

____ can influence bias

A

Instruction

239
Q

What will a good test have?

A
  • A good test will have lower sigma value so a lower difference between the means
  • A lower lateral distribution (which makes a larger d’)
240
Q

How to show the quality of signal detection?
- what does it show
- where are each represented?

A
  • How probabilities change with different d’ – shown by ROC curve
  • Receiver-operating characteristic—ROC curve
  • Show sensitivity and criterion at the same time
  • Sensitivity: rep by distance of ROC from the diagonal
  • Criterion: particular points along the curve
241
Q

Larger the d’, smaller the ____ when sensitivity is high

A

False alarm

242
Q

Implication of TSD

A
  • Important for psychoacoustic/neurological experiment
  • Design and assumption
  • Clear-cut of threshold does not exist
  • Outcome depends on methods

Audition II (7 decks)

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