EEG- Measurement & Development Flashcards

1
Q

How is EEG data practically used?

A

diagnostic marker of ADHD, medication effects, outcome measure for training studies, basis for all ERP studies, PPT

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2
Q

What do EEGs measure?

A

Measure of brain electrical activity, recorded during resting states and active processing.

Measuring outcome of action potential: NTs bind to post-synaptic receptors -> headed IPSPs and EPSPs (measure from EEG)

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3
Q

Where does rhythmical cortical EEG activity come from?

A

interaction between the thalamus and cortex

ARAS primary driver for cortical EEG

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4
Q

Who described the first “brain wave”?

A

Caton (1875) in rabbits and monkeys- primarily slow wave activity (probably delta)

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5
Q

Who described the first EEG activity in humans?

A

Berger (1929)- 2 basic wave patterns- large regular (alpha), smaller irregular (beta)

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6
Q

Who later discovered delta and theta?

A

William Grey Walter- discovered delta waves during sleep and theta

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7
Q

What are the characteristics of delta waves?

A

0.5-3.5Hz, 20-200uV, deep sleep, in very young children and in area of a lesion

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8
Q

What are the characteristics of theta waves?

A

4-7Hz, 20-100uV, more frequent in children, indicator of maturational lag and general marker of patient dysfunction (if patient alert & awake)

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9
Q

What are the characteristics of alpha waves?

A

8-12Hz, 20-60uV, relaxed waking state, eyes closed, mental inactivity, posterior dominant

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10
Q

What are the characteristics of beta waves?

A

13-25Hz, 2-20uV, mental activity, frontocentral

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11
Q

What are some less common waves?

A

Gamma- 30-120Hz? not heavily studied

Others: kappa, lambda, Mu

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12
Q

Whats involved in a monopolar EEG recording?

A

Most frequently used. reference sit to compare active data against (usually on ear)

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13
Q

Whats involved in a bipolar EEG recording?

A

Difference between 2 active electrodes (less frequently used)

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14
Q

What is the international 10-20 system?

A

international convention that allows comparison of results- electrodes used in measurements between several point, with most placed at intervals of 10% or 20% of the distance
Electrode cap has distances built in
(also international 10-10 with more electrodes)

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15
Q

What is spectral analysis?

A

Analysing the EEG- two ways:

  1. Time Domain: amount of EEG activity within a time (Hz)
  2. Frequency Domain: Amount of power within a given EEG frequency (uV)
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16
Q

What is Fast Fourier Transform (FFT)?

A

Algorithm that analyses each waveform and quantifies amount of power within it.

Absolute power: measure of magnitude of the power in the EEG or a specific frequency band measured in uV2
Relative power: Amount of power that one frequency band contributes to entire power of EEG as a %
eg. relative theta = Absolute theta/ absolute (delta+theta+alpha+beta) x100

17
Q

What is co-modulation/is it effective?

A

Correlation between the power (frequency domain) at two electrode sites supposedly represents as measure of the fundamental connectivity between two regions -> not mainstream use as unproven procedure

18
Q

What is EEG coherence?

A

Better way of doing what co-modulation is trying to.
Correlation in time domain between 2 signals in a given frequency band (how similar is the shape of the brain waves at 2 electrode sites?)
High coherence indicates two locations functionally and/or structurally connected