Mod A Flashcards
What does EEG primarily measure?
a) Action potentials of individual neurons
b) Summation of electrical potentials in the extracellular fluid of postsynaptic neurons
c) Magnetic fields generated by neurons
d) Blood flow in the brain
b) Summation of electrical potentials in the extracellular fluid of postsynaptic neurons
To create a measurable EEG signal, neurons must be:
a) Arranged randomly
b) Arranged in a parallel fashion (perpendicular to the cortex) and synchronously active
c) Aligned parallel to the cortex
d) Randomly aligned
b) Arranged in a parallel fashion (perpendicular to the cortex) and synchronously active
What is volume conduction in the context of EEG?
a) The transmission of sound waves in the brain
b) The process by which a pool of ions attracts nearby ions of the opposite charge, resulting in a wave of charge
c) The propagation of EEG signals within the brain through extracellular space
d) The conduction of electrical signals through individual neurons
c) The propagation of EEG signals within the brain through extracellular space
Why is electrode gel necessary in EEG recording?
a) To improve skin conductivity
b) To reduce impedance
c) To create a conductive path from the scalp to the electrode
d) All of the above
d) All of the above
What is the International 10/20 System used for in EEG electrode placement?
a) To identify 10 important EEG bands
b) To determine electrode impedance
c) To guide the placement of electrodes based on anatomical landmarks
d) To calibrate EEG amplification
c) To guide the placement of electrodes based on anatomical landmarks
What is the main purpose of an amplifier in an EEG system?
a) To maximize the Signal to Noise Ratio (SNR)
b) To increase the size of the noise
c) To reduce the amplitude of EEG signals
d) To amplify only negative voltage
a) To maximize the Signal to Noise Ratio (SNR)
Which EEG band is associated with relaxed wake state and lack of active cognitive processing?
a) Gamma
b) Alpha
c) Beta
d) Theta
b) Alpha
ERPs (Event-related potentials) are:
a) Continuous and spontaneous electrical activities
b) Small voltage fluctuations in the EEG time-locked to external or internal events
c) Large-amplitude oscillations in the brain
d) Long-duration electrical signals
b) Small voltage fluctuations in the EEG time-locked to external or internal events
What does the P300 component of ERPs primarily reflect?
a) Visual processing of faces
b) Motor preparation and execution
c) Allocation of attentional resources and working memory updating
d) Semantic processing
c) Allocation of attentional resources and working memory updating
What is the main advantage of EEGLab?
a) Excellent spatial resolution
b) Real-time source reconstruction
c) Free, works on Matlab, and analyzes data from different software
d) High-quality statistical analysis
c) Free, works on Matlab, and analyzes data from different software
What is the primary disadvantage of fMRI (Functional Magnetic Resonance Imaging) compared to EEG?
a) Limited temporal resolution
b) Excellent spatial resolution
c) Direct measurement of neuronal electrical activity
d) Low cost
a) Limited temporal resolution
Which of the following is an exogenous ERP component?
a) N170
b) P300
c) MMN (Mismatch Negativity)
d) N2c
c) MMN (Mismatch Negativity)
What is the primary function of the P600 ERP component?
a) Semantic processing
b) Syntactic violation in language processes
c) Allocation of attentional resources
d) Motor preparation and execution
c) Allocation of attentional resources
The readiness potential (RP or BP) is associated with:
a) Slow cortical negativity before the execution of voluntary movement
b) Sensory processing of visual stimuli
c) Auditory perception of discrepancies
d) Semantic integration of words in a sentence context
a) Slow cortical negativity before the execution of voluntary movement
What does CNV (Contingent Negative Variation) reflect in EEG?
a) Semantic processing of words
b) Sensory processing of visual stimuli
c) Expectancy, anticipatory attention, and motor preparation
d) Allocation of spatial attention
c) Expectancy, anticipatory attention, and motor preparation
In EEG, what is the role of ICA (Independent Component Analysis)?
a) Amplifying the EEG signal
b) Removing artifacts based on component maps
c) Measuring impedance of electrodes
d) Stimulating neural activity
b) Removing artifacts based on component maps
What is the primary purpose of averaging in ERP analysis?
a) To increase the size of noise in the signal
b) To reduce the Signal to Noise Ratio (SNR)
c) To enhance the amplitude of ERPs by summing random voltage
d) To reduce noise by aligning time-locked ERP activity across trials
d) To reduce noise by aligning time-locked ERP activity across trials
Why is electrode gel applied during EEG recording?
a) To improve skin conductivity and reduce impedance
b) To create a non-conductive barrier between the electrode and the skin
c) To minimize the saturation of space beneath the electrode
d) To amplify the EEG signals at the source
a) To improve skin conductivity and reduce impedance
What is the typical frequency range of the Gamma EEG band?
a) 0.5-3 Hz
b) 4-7 Hz
c) 8-13 Hz
d) 30-80 Hz
d) 30-80 Hz
How is SNR (Signal-to-Noise Ratio) measured in EEG?
a) By comparing the amplitude of the EEG signal to the frequency
b) By calculating the ratio of signal amplitude to noise amplitude
c) By measuring the impedance of electrodes
d) By counting the number of EEG channels
b) By calculating the ratio of signal amplitude to noise amplitude
What does the Nyquist rate represent in the context of A/D conversion in EEG recording?
a) The maximum frequency that can be accurately measured
b) The minimum frequency that can be accurately measured
c) The ratio of positive to negative electrode signals
d) The speed at which the converter samples the signal
a) The maximum frequency that can be accurately measured
What does the P1/N1 ERP component reflect?
a) Semantic processing of words
b) Allocation of spatial attention
c) Motor preparation and execution
d) Spatial focusing of attention
d) Spatial focusing of attention
In EEG electrode placement, what does the term “10/20” refer to?
a) The ratio of positive to negative electrode signals
b) The percentage of electrodes with good electrical conductance
c) The distance between electrodes on the scalp
d) The placement of electrodes based on four anatomical landmarks
d) The placement of electrodes based on four anatomical landmarks
What is the primary function of the REST (Reference Electrode Standardization Technique) in EEG?
a) To standardize the placement of electrodes on the scalp
b) To provide a reference that tends to infinite
c) To improve the SNR of EEG signals
d) To eliminate the need for electrode gel
b) To provide a reference that tends to infinite
Which EEG band is associated with active waking consciousness, alertness, and external attention?
a) Gamma
b) Beta
c) Alpha
d) Theta
b) Beta
What is the primary advantage of EEG over fMRI in terms of temporal resolution?
a) EEG has better spatial resolution
b) EEG has a lower sampling rate
c) EEG provides real-time measurements
d) EEG can measure hemodynamic changes
c) EEG provides real-time measurements
What does CNV (Contingent Negative Variation) reflect in EEG?
a) Visual processing of faces
b) Semantic processing of words
c) Expectancy, anticipatory attention, and motor preparation
d) Allocation of spatial attention
c) Expectancy, anticipatory attention, and motor preparation
Which ERP component is sensitive to the probability of a task-defined stimulus category?
a) P300
b) P3a
c) P3b
d) N400
a) P300
What is the role of ICA (Independent Component Analysis) in EEG data processing?
a) Amplifying the EEG signal
b) Enhancing the spatial resolution of EEG
c) Removing artifacts based on component maps
d) Creating reference electrodes
c) Removing artifacts based on component maps
What is the primary function of the amplifier in an EEG system?
a) To amplify only negative voltage
b) To reduce the Signal to Noise Ratio (SNR)
c) To maximize the SNR of the measured voltage
d) To decrease the amplitude of the EEG signal
c) To maximize the SNR of the measured voltage
In EEG, what is the purpose of skin preparation before electrode application?
a) To increase skin impedance
b) To decrease impedance below 5-10 kΩ
c) To enhance the amplitude of EEG signals
d) To create a non-conductive barrier between skin and electrodes
b) To decrease impedance below 5-10 kΩ
What is the primary advantage of using silver-silver chloride (Ag/AgCl) electrodes in EEG recording?
a) Higher impedance
b) Larger bias potential
c) Minimal polarization
d) Increased noise in the EEG signal
c) Minimal polarization
How does the Volume Conduction process contribute to the propagation of EEG signals within the brain?
a) By creating a wave of charge that travels through extracellular space
b) By generating electrical potentials in the postsynaptic neurons
c) By enhancing the amplitude of EEG signals
d) By preventing the cancellation of positive and negative signals
a) By creating a wave of charge that travels through extracellular space
What is the primary role of the Montage in EEG recording?
a) To amplify EEG signals
b) To filter out noise in the signal
c) To position electrodes on the scalp
d) To determine the reference electrode placement
c) To position electrodes on the scalp
What does the term “Bipolar Montage” in EEG recording refer to?
a) Both electrodes placed on active sites
b) One electrode on an “inactive” site and one on an active site
c) The arrangement of electrodes based on the 10/20 system
d) Amplification of the EEG signal
a) Both electrodes placed on active sites
What is the primary advantage of the EEG system’s A/D conversion in digital recording?
a) To increase the size of noise in the signal
b) To convert the signal into a numerical form for storage
c) To decrease the speed of the signal sampling rate
d) To minimize the amplitude of EEG signals
b) To convert the signal into a numerical form for storage
What is the primary function of the amplifier in an EEG system?
a) To maximize the Signal to Noise Ratio (SNR) of the measured voltage
b) To increase the size of noise in the signal
c) To decrease the amplitude of the EEG signal
d) To reduce the speed of the signal sampling rate
a) To maximize the Signal to Noise Ratio (SNR) of the measured voltage
What is the primary purpose of EEG Band analysis?
a) To measure skin impedance
b) To assess the amplitude of EEG signals
c) To categorize EEG based on frequency bands
d) To determine electrode placement on the scalp
c) To categorize EEG based on frequency bands
What is the primary advantage of using fNIRS (Functional Near-Infrared Spectroscopy) over fMRI in functional brain imaging?
a) Better spatial resolution
b) Real-time measurements
c) Limited temporal resolution
d) Excellent temporal resolution
b) Real-time measurements
What is the primary limitation of EEG compared to fMRI in functional brain imaging?
a) Poor spatial resolution
b) Limited temporal resolution
c) Excellent temporal resolution
d) Direct measurement of neuronal electrical activity
a) Poor spatial resolution
What is the primary purpose of the Reference Electrode in EEG?
a) To maximize the amplitude of EEG signals
b) To minimize the amplitude of EEG signals
c) To provide a neutral site for voltage measurement
d) To reduce the speed of the signal sampling rate
c) To provide a neutral site for voltage measurement
What is the primary difference between exogenous and endogenous ERP components?
a) Exogenous components reflect entirely cognitive processes, while endogenous components reflect sensory activity.
b) Exogenous components are triggered by external stimuli, while endogenous components are entirely cognitive processes.
c) Exogenous components are modulated by top-down processes, while endogenous components are influenced by stimulus physical parameters.
d) Exogenous components have a latency of less than 100 ms, while endogenous components have a latency greater than 250 ms.
b) Exogenous components are triggered by external stimuli, while endogenous components are entirely cognitive processes.
What is the role of MMN (Mismatch Negativity) in ERP?
a) To reflect semantic processing of words
b) To respond to novel and unexpected stimuli
c) To indicate allocation of spatial attention
d) To measure motor preparation and execution
b) To respond to novel and unexpected stimuli
In EEG, what is the role of the ERP component N400?
a) It reflects semantic processing of words and the associative strength in semantic memory.
b) It measures perceptual processing of faces.
c) It is associated with the P300 component in auditory processing.
d) It is a positive wave related to language processes.
a) It reflects semantic processing of words and the associative strength in semantic memory.
What is the primary function of the Contingent Negative Variation (CNV) in EEG?
a) To reflect sensory activity from primary sensory brain areas.
b) To indicate allocation of spatial attention.
c) To facilitate S2 stimulus processing.
d) To measure semantic processing of words.
b) To indicate allocation of spatial attention.
What is the primary purpose of pre-processing steps such as ICA and artifact removal in EEG analysis?
a) To increase the amplitude of EEG signals.
b) To eliminate ERPs from the recorded data.
c) To enhance the spatial resolution of EEG.
d) To remove unwanted interference signals that contaminate the signal of interest.
d) To remove unwanted interference signals that contaminate the signal of interest.
In EEG recording, what does the Slow Cortical Potentials refer to?
a) Slow surface negativity reflecting cortical facilitation.
b) Rapid fluctuations in the excitability of populations of neurons.
c) Event-related cortical activity that lasts from 300 ms to several seconds.
d) Negative event-related cortical activity developing about 1500 ms before voluntary movement.
c) Event-related cortical activity that lasts from 300 ms to several seconds.
What is the primary role of the A/D conversion process in digital recording in EEG?
a) To decrease the size of the EEG signal.
b) To increase the speed of the signal sampling rate.
c) To convert the EEG signal into a numerical form for storage.
d) To minimize the amplitude of the noise in the signal.
c) To convert the EEG signal into a numerical form for storage.
Which EEG frequency band is associated with memory consolidation during sleep?
a) Gamma
b) Beta
c) Theta
d) Delta
d) Delta
What is the primary advantage of using EEG over fMRI for studying real-time brain activity?
a) Better spatial resolution
b) Lower sampling rate
c) Real-time measurements
d) Excellent temporal resolution
c) Real-time measurements
