Instrumentation For Neurofeedback Flashcards
EOG artifact in EEG recording is due to
Electrical potential differences between the aqueous and vitreous humors of the eye
I blinks an eye movements, produce artifacts that may fall within the _______ range
Delta and theta
What is related to EEG signal frequency
Cycles per second
If your voltage is 24 & resistance is 2, current is ______ amperes.
12
Which band pass can be used to measure alpha EEG activity.
8 - 12 Hz
And impedance meter measures the quality of skin – electric contact in
Kohms
What is specified in dB/octave?
Filter Slope
Power refers to the square of signal
Amplitude
________ artifact is usually the strongest source of contamination during EEG recording.
Sixty Hz (50 Hz)
What can worse than movement artifact in EEG recording
Lengthening the EEG cable
SMR activity can be detected from
12-15 Hz
The majority of EEG power falls between
0-20 Hz
The EEG primarily reflects, graded _________ Potentials in _______
Excitatory and inhibitory
Dendrites
What EEG landmark is closest to the ear
Preauricular point
In North America, contamination from line, current occurs primarily at
60 Hz
Standard electric placement system draws an imaginary line from the nasion to the
Inion
A ______ wave is a slow Cortical potential
P300
Which bandpass can be used to measure Theta EEG activity
4-7 Hz
AnEEG signal is measured in microvolts. A microphone is _______ of a volt.
1/1,000,000
Breathing pattern can influence EEG training. For example, when hyperventilation constricts cerebral blood vessels, it generates ________ activity.
Theta
Which circuit does a blown fuse illustrate
Open circuit
What measures and electroencephalograph’s ability to detect the smallest signal voltage
Sensitivity
How would you control eye-movement artifact?
- Monitoring, vertical and horizontal EOG artifacts.
- Exclude contaminated epoch
- Use a high pass filter to exclude activity in the Delta range
When there’s a break in an electrode cable, impedance measured from both ends of the cable should be _____ ohms
Infinite
EEG signals are converted into ____ during optical, isolation
Light
Which filter select signals below a specified cut off frequency
Low-pass filter
Which technique is used to quantify EEG amplitude within a specific frequency bands
FFT
If a signal amplitude is one microvolts at Midland, the amplitude at the corner frequencies is _____ microvolts
.707
A notch filter to remove line current noise typically operates from ____\ in North America.
58 - 62 Hz
The highest amplitude EEG frequency band is called the ______ frequency
Dominant
Which common mode rejection, ratio specifications would you prefer in an electroencephalograph?
110 dB
What index is an EEG’s ability to detect the smallest change in activity
Resolution
What is typically the strongest source of interference in EEG recording?
60 Hz artifact
A one second exposure to currents of _______ mA can produce ventricular fibrillation
50 mA
What filter select signals above a specified, cut off frequency
High pass filter
A dummy subject is used with EEG or EMG instruments to measure
Both environmental and instrument noise
Opposition to the movement of an AC signal through a circuit is called
Impedance
What is measured in microvolts
Signal strength
Which integration method produces the highest EEG and EMG values
Peak to peak
What forces electrons to move in a circuit
Electromotive force
Where is alpha, amplitude lowest in a healthy subject
Frontal lobe
Sudden limb and electrode cable movement will most affect the _____ band
Delta
Your electroencephalograph’s display shows two microvolts. During which stage of processing was the value calculated.
Integration
Which term refers to the combination of electrodes used in a single amplifier channel
Derivation
What describes a differential amplifier
Subtract identical input signals
Sterman recommends using _____ to represent EEG power in descriptive statistics
The natural log transformation of microvolts
How does a ground fault interrupter circuit, protect against shock
Triggers a circuit breaker when there is leakage
EEG electrodes are located blank of the distance between the nasion and the inion, and between the left preauricular point, and right preauricular point
10 or 20%
Which term means a segment of a biofeedback or neurofeedback recording
Epoch
A conservative guideline is that impedance values for disc electrodes should not exceed _____ kohms , and it should be balanced with _____ kohms to ensure acceptable common motor ejection and high sensitivity
5; 1
What material produces the lowest electrode noise
Silver silver-chloride
How can you control radio Frequency artifact
- Select a 40 Hz. High pass filter.
- Locate encoders away from high frequency, artifact sources.
- Remove unused sensor cables from the encoder box.
A one second exposure to current exceeding _____ mA can produce injury
5 mA
Name the international EEG electrode placement system
10-20 international system of electrode placement
_____ is the correlation between the amplitude of specific frequencies, recorded a different sites overtime and specific conditions.
Comodulation
A blown fuse illustrates what kind of circuit
Open
What would help reduce 60 Hz noise during EEG & SEMG recording
Differential amplifier
When a faulty electrode connection results in a sudden voltage discharge, this produces….
Electrode pop, artifact
Which electroencephalograph differential input impedance specification is best
10 megohms
Which method produces the largest signal voltage by transforming both positive and - halves into an equivalent, DC signal
Full wave rectification
Which term refers to a signal sampling.
Epoch
Which is the first amplification stage in an instrument that requires several stages to increase a low level signal to voltage levels, requiring for processing?
Preamplifier
_____ is the rate of electron movement through a circuit
Current
A(n) ______ multiplies the voltage of a low amplitude signal
Amplifier
In ______, EEG signals are rapidly sampled, digitized, and decomposed into a series of wave forms of different frequencies. This technique calculates amplitude for frequencies within a band, passed to determine the power distribution of a signal.
FFT
_______ refers to the actual frequency selected by a filter for further analysis
Bandpass
An amplifier is differential input impedance should be at least ______ times the skin electrode impedance
100
Which integration method results in a voltage that is two times peak voltage?
Peak to peak
Which is the proportion of signal to artifact amplitude measured in dB?
Signal to noise ratio
_____ occurs when an EMG signal travels to an EEG electrode and contaminates these recordings
Volume conduction
Which of these is an interval between two frequencies that represents a 2:1 ratio
Octave
______ is the ability of a differential amplifier to subtract signals common to active and reference electrodes
Common mode rejection
Which is a unit of resistance
Ohm
Which of these converts a filtered AC signal into a positive DC signal for integration?
Rectifier
________ refers to a point on a waveforms 360° cycle had an instant in time.
Phase
An ________ prevents current flow under normal circumstances
Insulator
What measures the noise due to instrument an environmental sources?
Dummy subject
The ______ is the absolute difference between the high pass and low pass frequencies, measured in hertz
Bandwidth
What protects a patient from shock hazard by converting an electrical signal to a beam of light that is projector across a gap and re-converted into a electrical signal?
Optical isolator
