Q.1 What does the acronym BCI stand for in neuroengineering?
Brain-Computer Interface
Biological Circuit Integration
Brain-Controlled Instrument
Bioelectric Communication Interface
Explanation - BCI stands for Brain‑Computer Interface, a system that translates brain activity into commands for external devices.
Correct answer is: Brain-Computer Interface
Q.2 Which of the following is a non‑invasive method for acquiring brain signals in BCI systems?
Electrocorticography (ECoG)
Intracortical microelectrodes
Electroencephalography (EEG)
Deep brain stimulation electrodes
Explanation - EEG records electrical activity from the scalp and does not require surgery, making it non‑invasive.
Correct answer is: Electroencephalography (EEG)
Q.3 In a typical BCI pipeline, which step follows signal acquisition?
Feature extraction
Actuator control
User training
Signal amplification
Explanation - After acquiring raw brain signals, the next step is to extract informative features (e.g., frequency bands) for classification.
Correct answer is: Feature extraction
Q.4 Which frequency band of EEG is most commonly associated with motor imagery tasks?
Delta (0.5‑4 Hz)
Theta (4‑8 Hz)
Alpha (8‑12 Hz)
Mu (8‑13 Hz)
Explanation - The mu rhythm, a subset of the alpha band, desynchronizes during motor imagination and is widely used in BCI control.
Correct answer is: Mu (8‑13 Hz)
Q.5 What is the primary advantage of using invasive BCI over non‑invasive BCI?
Lower cost
Higher spatial resolution
Easier regulatory approval
No need for surgical procedures
Explanation - Invasive BCIs place electrodes directly on or inside brain tissue, providing finer spatial detail than scalp‑recorded signals.
Correct answer is: Higher spatial resolution
Q.6 Which of the following is a common classification algorithm used in EEG‑based BCIs?
K‑Nearest Neighbors (KNN)
Support Vector Machine (SVM)
Linear Discriminant Analysis (LDA)
All of the above
Explanation - KNN, SVM, and LDA are all frequently applied to distinguish mental states from extracted EEG features.
Correct answer is: All of the above
Q.7 The term "P300" in BCI refers to:
A type of motor evoked potential
A positive EEG deflection occurring ~300 ms after a rare stimulus
The third phase of a brain‑wave cycle
A proprietary BCI hardware platform
Explanation - The P300 is an event‑related potential used in speller BCIs, appearing about 300 ms after an unexpected stimulus.
Correct answer is: A positive EEG deflection occurring ~300 ms after a rare stimulus
Q.8 Which component of a BCI translates classified brain signals into physical actions?
Signal acquisition module
Feature extraction module
Decoder/translator module
Feedback module
Explanation - The decoder (or translator) converts the classification output into commands for the output device.
Correct answer is: Decoder/translator module
Q.9 In the context of BCI, what does “feedback” refer to?
The electrical noise from the recording hardware
Visual or auditory information provided to the user about performance
The power supply to the electrodes
The latency of the signal processing pipeline
Explanation - Feedback helps users learn to modulate their brain activity by showing the consequences of their actions in real time.
Correct answer is: Visual or auditory information provided to the user about performance
Q.10 Which of these applications is NOT a typical use of BCIs?
Control of prosthetic limbs
Communication for locked‑in patients
Direct control of external drones
Increasing heart rate during exercise
Explanation - BCIs are used for communication, control, and rehabilitation, but they do not directly manipulate physiological functions like heart rate.
Correct answer is: Increasing heart rate during exercise
Q.11 What does the term "signal‑to‑noise ratio (SNR)" describe in EEG recordings?
The ratio of electrode impedance to scalp resistance
The proportion of useful brain activity relative to background noise
The speed of data transmission from the amplifier
The number of channels used in the system
Explanation - Higher SNR means the brain signal is clearer compared to electrical and muscular artifacts.
Correct answer is: The proportion of useful brain activity relative to background noise
Q.12 Which artifact is most likely to contaminate EEG recordings during BCI operation?
Eye blinks
Room temperature changes
Battery level of the amplifier
Wi‑Fi signal strength
Explanation - Eye movements and blinks produce large potentials (electrooculogram) that overlap EEG frequency bands.
Correct answer is: Eye blinks
Q.13 A common method for reducing dimensionality of EEG features before classification is:
Fourier Transform
Principal Component Analysis (PCA)
Laplace Filtering
Binary Thresholding
Explanation - PCA projects high‑dimensional data onto a smaller set of orthogonal components that retain most variance.
Correct answer is: Principal Component Analysis (PCA)
Q.14 Which of the following best describes a "closed‑loop" BCI?
A system where the user only receives visual feedback
A system that records brain signals but does not act on them
A system that continuously updates its output based on real‑time brain activity and feedback
A system that operates offline after data collection
Explanation - Closed‑loop BCIs provide ongoing interaction, allowing the user to adapt and the system to adjust in real time.
Correct answer is: A system that continuously updates its output based on real‑time brain activity and feedback
Q.15 The term "motor imagery" in BCI research refers to:
Actual movement of a limb
Thinking about moving a limb without physical execution
Imagining the sound of a motor vehicle
Visualizing a computer motor
Explanation - Motor imagery involves mentally simulating movement, which produces detectable EEG patterns useful for BCI control.
Correct answer is: Thinking about moving a limb without physical execution
Q.16 Which of the following is a major ethical concern for invasive BCIs?
High power consumption
Risk of infection and brain tissue damage
Limited battery life
Difficulty in signal amplification
Explanation - Implanting electrodes requires surgery, introducing risks of infection, scarring, and long‑term neural damage.
Correct answer is: Risk of infection and brain tissue damage
Q.17 In the context of BCI, the term "transfer learning" is used to describe:
Moving a BCI system from one lab to another
Training a model on one user’s data and adapting it to another user
Transferring electrical power between devices
Learning to transfer files via brain signals
Explanation - Transfer learning aims to reduce calibration time by reusing knowledge across subjects.
Correct answer is: Training a model on one user’s data and adapting it to another user
Q.18 Which hardware component is essential for amplifying EEG signals before digitization?
Low‑noise preamplifier
Digital signal processor (DSP)
Bluetooth transceiver
Power supply regulator
Explanation - EEG signals are in the microvolt range; a low‑noise preamp boosts them while preserving signal integrity.
Correct answer is: Low‑noise preamplifier
Q.19 What does the term "brain‑controlled cursor" refer to in BCI demonstrations?
A software mouse moved by decoded EEG patterns
A physical device implanted in the brain
A virtual reality headset
An eye‑tracking system
Explanation - Early BCI experiments used decoded EEG to move a cursor on a screen, allowing users to select letters or icons.
Correct answer is: A software mouse moved by decoded EEG patterns
Q.20 Which of the following signal processing steps removes line‑frequency interference (e.g., 50/60 Hz) from EEG recordings?
Band‑pass filtering
Notch filtering
Low‑pass filtering
High‑pass filtering
Explanation - A notch filter attenuates a narrow frequency band, typically centered at 50 Hz (Europe) or 60 Hz (USA) to eliminate mains hum.
Correct answer is: Notch filtering
Q.21 Which of the following best describes the "Hybrid BCI" concept?
Combining invasive and non‑invasive electrodes in the same system
Using both brain signals and peripheral physiological signals (e.g., EMG) for control
Merging BCI with traditional keyboard input
Integrating multiple BCI software libraries
Explanation - Hybrid BCIs fuse brain activity with other biosignals to improve reliability and command repertoire.
Correct answer is: Using both brain signals and peripheral physiological signals (e.g., EMG) for control
Q.22 What is the typical latency (delay) between a user's intention and the resulting action in a well‑designed BCI?
1‑2 ms
10‑30 ms
100‑300 ms
1‑2 seconds
Explanation - Processing, classification, and actuation usually introduce a delay of a few hundred milliseconds, which is acceptable for many applications.
Correct answer is: 100‑300 ms
Q.23 Which of the following is a common metric for evaluating BCI performance?
Bits per minute (BPM)
Classification accuracy
Signal voltage range
Electrode impedance
Explanation - Accuracy (percentage of correctly classified trials) is the standard measure for assessing a BCI's reliability.
Correct answer is: Classification accuracy
Q.24 In BCI literature, the term "SMR" stands for:
Sensorimotor Rhythm
Standard Magnetic Resonance
Signal Modulation Ratio
Spatial Memory Recall
Explanation - SMR refers to the 12‑15 Hz rhythm over sensorimotor cortex, often modulated during motor imagery tasks.
Correct answer is: Sensorimotor Rhythm
Q.25 Which brain region is primarily targeted for motor‑related BCIs?
Occipital lobe
Temporal lobe
Primary motor cortex (M1)
Cerebellum
Explanation - M1 generates signals directly linked to voluntary movement, making it a prime source for motor BCIs.
Correct answer is: Primary motor cortex (M1)
Q.26 A "speller" BCI based on the P300 paradigm works by:
Detecting eye‑movement patterns
Identifying a positive EEG peak when a desired letter flashes
Measuring muscle tension when a key is pressed
Translating spoken words into text
Explanation - The user focuses on a target character; when it flashes, a P300 response is elicited and detected by the system.
Correct answer is: Identifying a positive EEG peak when a desired letter flashes
Q.27 Which of the following is a limitation of EEG‑based BCIs compared to invasive BCIs?
Higher spatial resolution
Longer battery life
Susceptibility to motion artifacts
Direct access to single‑neuron activity
Explanation - EEG signals are easily contaminated by muscle movement and electrode shifts, reducing reliability.
Correct answer is: Susceptibility to motion artifacts
Q.28 In BCI research, the term "band‑power" usually refers to:
The total power of all recorded EEG channels
Power in a specific frequency band (e.g., alpha, beta)
The electrical power supplied to the amplifiers
Battery capacity of the headset
Explanation - Band‑power features are computed by integrating the power spectral density over a chosen frequency range.
Correct answer is: Power in a specific frequency band (e.g., alpha, beta)
Q.29 Which of these is NOT a typical step in preprocessing EEG for BCI?
Re-referencing
Artifact rejection
Fourier transform
Voltage amplification
Explanation - Amplification occurs before acquisition; preprocessing includes referencing, filtering, and artifact handling.
Correct answer is: Voltage amplification
Q.30 What does the term "dry electrodes" imply in EEG‑based BCIs?
Electrodes that do not require conductive gel
Electrodes that are completely waterproof
Electrodes that are disposable after each use
Electrodes that operate without power
Explanation - Dry electrodes simplify setup by eliminating the need for conductive paste, though they may have higher impedance.
Correct answer is: Electrodes that do not require conductive gel
Q.31 Which of the following BCI applications is most promising for restoring mobility in spinal‑cord‑injured patients?
P300 speller
Motor‑imagery control of robotic exoskeletons
Emotion‑based music selection
Visual attention monitoring
Explanation - Motor imagery can be decoded to drive exoskeleton joints, helping users regain walking capability.
Correct answer is: Motor‑imagery control of robotic exoskeletons
Q.32 Which of the following best describes "cross‑subject generalization" in BCI research?
Using the same hardware for multiple subjects
Training a classifier on data from one subject and testing on another
Sharing EEG recordings among laboratories
Standardizing electrode placement across studies
Explanation - Cross‑subject generalization measures how well a model trained on one user works for a different user.
Correct answer is: Training a classifier on data from one subject and testing on another
Q.33 When designing a BCI for a pediatric population, which factor is most critical?
Ensuring the headset is lightweight and comfortable
Maximizing the number of electrodes
Using invasive electrode arrays
Implementing high‑frequency sampling (>10 kHz)
Explanation - Children are sensitive to weight and discomfort; ergonomics is essential for compliance and data quality.
Correct answer is: Ensuring the headset is lightweight and comfortable
Q.34 Which of the following best defines the term "neuroplasticity" in the context of BCI training?
The brain's ability to generate electrical currents
Changes in neural pathways due to repeated BCI use
The permanent loss of brain cells after electrode implantation
The static nature of brain connectivity
Explanation - Neuroplasticity allows the brain to adapt and improve control over time with BCI feedback.
Correct answer is: Changes in neural pathways due to repeated BCI use
Q.35 Which data format is commonly used for storing raw EEG recordings in BCI research?
JPEG
CSV
EDF (European Data Format)
MP4
Explanation - EDF is a standard file format for physiological signals, including EEG, facilitating data exchange.
Correct answer is: EDF (European Data Format)
Q.36 What is the purpose of a "ground electrode" in an EEG cap?
To transmit data to the computer
To reference all other electrodes to a common potential
To measure the user's heart rate
To supply power to the amplifiers
Explanation - The ground electrode provides a stable reference, reducing common‑mode noise.
Correct answer is: To reference all other electrodes to a common potential
Q.37 Which of the following is a typical sampling rate for EEG acquisition in BCI systems?
50 Hz
250 Hz
1 kHz
10 kHz
Explanation - A sampling rate of 250 Hz captures the relevant EEG frequencies (up to ~100 Hz) while keeping data size manageable.
Correct answer is: 250 Hz
Q.38 In a motor‑imagery BCI, the user is asked to imagine moving the left hand. Which EEG change is typically observed over the right motor cortex?
Increase in alpha power
Decrease in mu rhythm (desynchronization)
Increase in delta waves
Constant high gamma activity
Explanation - Imagined movement reduces mu (8‑13 Hz) power over the contralateral sensorimotor area, known as event‑related desynchronization.
Correct answer is: Decrease in mu rhythm (desynchronization)
Q.39 Which of these is a potential advantage of using functional near‑infrared spectroscopy (fNIRS) in BCI?
Higher temporal resolution than EEG
Direct measurement of neuronal action potentials
Portability and tolerance to movement artifacts
Ability to record deep brain activity
Explanation - fNIRS measures hemodynamic responses, is relatively portable, and is less affected by muscle artifacts than EEG, though it has slower dynamics.
Correct answer is: Portability and tolerance to movement artifacts
Q.40 Which term describes a BCI that uses the user's emotional state (e.g., affective EEG) for control?
Affective BCI
Cognitive BCI
Motor BCI
Sensory BCI
Explanation - Affective BCIs interpret emotional or affective EEG signatures to influence system behavior.
Correct answer is: Affective BCI
Q.41 When evaluating a BCI system, the term "information transfer rate (ITR)" measures:
The bandwidth of the wireless link
The speed at which the user can convey commands, measured in bits per minute
The power consumption of the device
The number of electrodes used
Explanation - ITR quantifies communication efficiency; higher ITR indicates faster and more accurate control.
Correct answer is: The speed at which the user can convey commands, measured in bits per minute
Q.42 Which of the following best explains why high‑density EEG caps (e.g., 128 channels) may improve BCI performance?
They reduce the need for amplification
They provide richer spatial information for feature extraction
They eliminate the need for preprocessing
They automatically classify mental states
Explanation - More channels capture finer spatial patterns, aiding discrimination of mental states, though they increase setup time.
Correct answer is: They provide richer spatial information for feature extraction
Q.43 Which of the following is a legal consideration when deploying BCIs for commercial use?
Ensuring the device meets electromagnetic compatibility (EMC) standards
Choosing a bright LED for status indication
Using the latest Bluetooth version
Providing a USB-C connector
Explanation - Regulatory compliance, including EMC and medical device safety, is essential for commercial BCI products.
Correct answer is: Ensuring the device meets electromagnetic compatibility (EMC) standards
Q.44 What does the term "brain‑machine synergy" refer to in advanced BCI research?
The combination of brain signals with machine learning to create adaptive interfaces
Physical bonding of the brain to a computer chip
Using brain signals to power machines directly
A legal partnership between neuroscientists and engineers
Explanation - Synergy emphasizes the co‑adaptation of the user and the algorithm, improving performance over time.
Correct answer is: The combination of brain signals with machine learning to create adaptive interfaces
Q.45 Which of the following signal features is most associated with the gamma band (30‑80 Hz) in BCI?
Slow wave sleep
High‑frequency oscillations linked to attention and motor execution
Eye‑blink artifacts
Baseline drift
Explanation - Gamma activity rises during focused attention and movement, and can be leveraged for BCI control.
Correct answer is: High‑frequency oscillations linked to attention and motor execution
Q.46 Which of the following is a primary challenge when using BCIs for communication with locked‑in syndrome patients?
Limited battery life of the headset
Low signal‑to‑noise ratio due to muscle atonia
Excessive data storage requirements
Difficulty in calibrating the wireless link
Explanation - Patients often cannot generate strong voluntary signals, making reliable detection of intentional patterns difficult.
Correct answer is: Low signal‑to‑noise ratio due to muscle atonia
Q.47 In BCI terminology, the word "decoder" is synonymous with:
Signal amplifier
Feature extractor
Classifier that maps features to commands
Battery management unit
Explanation - A decoder interprets extracted features and decides which output command to issue.
Correct answer is: Classifier that maps features to commands
Q.48 Which of the following best illustrates a real‑world BCI application in gaming?
Using EEG to control a racing car's steering wheel
Controlling a game character's movement by focusing on visual cues (e.g., P300)
Using eye‑tracking to aim in a shooter
Voice commands to change weapons
Explanation - P300‑based BCIs have been used to select actions in games by attending to flashing targets.
Correct answer is: Controlling a game character's movement by focusing on visual cues (e.g., P300)
Q.49 Which of the following describes a common method for reducing inter‑channel noise in EEG?
Common average referencing (CAR)
Increasing the gain of the amplifier
Using a higher sampling rate
Adding more electrodes
Explanation - CAR subtracts the average of all channels from each channel, reducing common noise.
Correct answer is: Common average referencing (CAR)
Q.50 What is the primary function of a "stimulus presentation module" in a P300 speller BCI?
To amplify EEG signals
To display flashing characters and synchronize timing
To store user data securely
To calibrate electrode impedance
Explanation - The stimulus module controls visual events whose timing is critical for detecting the P300 response.
Correct answer is: To display flashing characters and synchronize timing
Q.51 Which of the following is a typical limitation of fMRI‑based BCIs compared to EEG‑based BCIs?
Lower spatial resolution
Very high temporal resolution
Large, immobile equipment and high cost
Inability to detect hemodynamic changes
Explanation - fMRI provides excellent spatial resolution but requires a scanner, making it impractical for everyday BCI use.
Correct answer is: Large, immobile equipment and high cost
Q.52 Which machine‑learning technique is specifically designed to handle sequential data, making it suitable for time‑series EEG?
Convolutional Neural Networks (CNN)
Recurrent Neural Networks (RNN)
Decision Trees
k‑Means clustering
Explanation - RNNs retain information across time steps, ideal for modeling temporal dependencies in EEG.
Correct answer is: Recurrent Neural Networks (RNN)
Q.53 What does the term "online calibration" refer to in BCI systems?
Adjusting the classifier while the user is actively using the system
Updating the firmware over the internet
Changing electrode placement between sessions
Increasing the sampling rate during data collection
Explanation - Online calibration adapts the model in real time to compensate for signal drift or user fatigue.
Correct answer is: Adjusting the classifier while the user is actively using the system
Q.54 Which of the following is a standard open‑source software platform for building BCIs?
MATLAB
OpenVibe
Photoshop
AutoCAD
Explanation - OpenVibe provides tools for real‑time EEG acquisition, processing, and BCI application development.
Correct answer is: OpenVibe
Q.55 In the context of BCIs, the term "command latency" is most affected by:
Electrode material
Signal processing and classification time
Color of the headset
User’s eye color
Explanation - The delay between intent detection and device actuation depends largely on algorithmic processing speed.
Correct answer is: Signal processing and classification time
Q.56 Which physiological signal, besides EEG, is sometimes combined with it to improve BCI robustness?
Electromyography (EMG)
Electrocardiography (ECG)
Electrodermal activity (EDA)
All of the above
Explanation - Hybrid BCIs may fuse EEG with EMG, ECG, or EDA to exploit complementary information and reduce false detections.
Correct answer is: All of the above
Q.57 Which of the following is a potential risk of long‑term use of invasive BCIs?
Reduced battery life of the external device
Scar tissue formation (gliosis) around electrodes
Increased Wi‑Fi interference
Decreased EEG sampling rate
Explanation - Glial scarring can increase impedance and degrade signal quality over time.
Correct answer is: Scar tissue formation (gliosis) around electrodes
Q.58 When using a motor‑imagery BCI, the user typically receives feedback via:
Auditory tones only
Visual cursor movement or virtual avatar motion
Haptic vibration on the forearm
All of the above
Explanation - Multimodal feedback (visual, auditory, haptic) can enhance learning and control accuracy.
Correct answer is: All of the above
Q.59 What is a primary advantage of using a “wet” EEG electrode compared to a “dry” one?
Lower contact impedance and better signal quality
No need for skin preparation
Cheaper manufacturing cost
Longer lifespan without cleaning
Explanation - Conductive gel reduces impedance, resulting in higher fidelity recordings.
Correct answer is: Lower contact impedance and better signal quality
Q.60 Which of the following best describes a "steady‑state visual evoked potential" (SSVEP) BCI?
A system that detects spontaneous brain rhythms without external stimuli
A BCI that uses flickering visual stimuli at specific frequencies to generate identifiable EEG responses
A BCI that records auditory evoked potentials
A BCI that relies on muscle potentials
Explanation - SSVEP BCIs present stimuli flashing at distinct frequencies; the EEG shows corresponding frequency peaks that can be decoded.
Correct answer is: A BCI that uses flickering visual stimuli at specific frequencies to generate identifiable EEG responses
Q.61 In BCI research, the term "cortical plasticity" is most closely related to:
Changes in skull thickness
Alterations in cortical representation due to learning and BCI use
Variations in blood pressure
Fluctuations in ambient temperature
Explanation - Cortical plasticity describes how repeated BCI training can reorganize neural maps, improving performance.
Correct answer is: Alterations in cortical representation due to learning and BCI use
Q.62 Which of the following is a typical method for evaluating the statistical significance of BCI classification results?
t‑test comparing accuracy against chance level
Measuring battery voltage
Counting the number of electrodes
Assessing Wi‑Fi signal strength
Explanation - Statistical tests (e.g., t‑test, permutation test) determine whether observed accuracy exceeds what would be expected by random guessing.
Correct answer is: t‑test comparing accuracy against chance level
Q.63 Which of the following best explains why BCI systems often require a calibration session before use?
To charge the device batteries
To personalize the classifier to the user’s unique brain signal patterns
To install operating system updates
To test Wi‑Fi connectivity
Explanation - Individual variability in EEG necessitates a brief training phase to tailor the model to each user.
Correct answer is: To personalize the classifier to the user’s unique brain signal patterns
Q.64 What does the term "brain‑computer symbiosis" imply for future BCI development?
Merging the hardware of the brain and computer into a single chip
A mutual adaptation where both the user and the algorithm continuously improve each other’s performance
Using brain tissue as a power source
Eliminating the need for any external device
Explanation - Symbiosis emphasizes co‑learning, with the system adjusting to the user and the user adapting to the system.
Correct answer is: A mutual adaptation where both the user and the algorithm continuously improve each other’s performance
Q.65 Which of the following BCI paradigms is most suitable for users who cannot control eye movements?
P300 speller
SSVEP
Motor‑imagery
Eye‑tracking interface
Explanation - Motor‑imagery does not rely on eye movements, making it appropriate for users with severe oculomotor impairments.
Correct answer is: Motor‑imagery
Q.66 In a BCI system, which component is primarily responsible for converting digital signals into physical actions (e.g., moving a robotic arm)?
Signal acquisition module
Feature extraction module
Actuator driver
Ground electrode
Explanation - The actuator driver receives commands from the decoder and sends appropriate control signals to hardware devices.
Correct answer is: Actuator driver
Q.67 Which of the following best describes the role of "artifact rejection" in EEG preprocessing?
Increasing the sampling frequency
Removing segments contaminated by eye blinks, muscle activity, or line noise
Amplifying the raw brain signal
Storing data in a cloud server
Explanation - Artifact rejection cleans the data to improve classification accuracy.
Correct answer is: Removing segments contaminated by eye blinks, muscle activity, or line noise
Q.68 Which of the following is a common benchmark dataset used for evaluating EEG‑based BCI algorithms?
ImageNet
UCI Machine Learning Repository – EEG Motor Imagery
CIFAR‑10
MNIST
Explanation - The UCI EEG Motor Imagery dataset provides standardized recordings for algorithm comparison.
Correct answer is: UCI Machine Learning Repository – EEG Motor Imagery
Q.69 Which of the following statements about BCI “latency” is correct?
Lower latency always improves classification accuracy
Higher latency improves user comfort
Latency is the time delay between user intent and system response
Latency is measured in volts
Explanation - Latency quantifies the temporal gap between brain activity detection and the resulting action.
Correct answer is: Latency is the time delay between user intent and system response
Q.70 What is the typical frequency range of the alpha band in EEG?
0.5‑4 Hz
4‑8 Hz
8‑12 Hz
30‑80 Hz
Explanation - Alpha rhythms occupy 8‑12 Hz and are prominent during relaxed wakefulness with eyes closed.
Correct answer is: 8‑12 Hz
Q.71 Which of the following best describes a “brain‑controlled prosthetic hand”?
A hand that moves automatically without user input
A prosthetic limb whose movements are driven by decoded brain signals
A robotic hand that uses voice commands
A glove that records hand temperature
Explanation - The BCI translates the user’s intent into motor commands that operate the prosthetic.
Correct answer is: A prosthetic limb whose movements are driven by decoded brain signals
Q.72 In BCI research, the term "overfitting" refers to:
A model that performs well on training data but poorly on new data
A hardware malfunction in the amplifier
Excessive electrode impedance
Using too many participants in a study
Explanation - Overfitting occurs when a classifier captures noise rather than underlying patterns, limiting generalization.
Correct answer is: A model that performs well on training data but poorly on new data
Q.73 Which of the following BCI modalities directly measures changes in blood oxygenation?
EEG
fNIRS
EMG
EOG
Explanation - Functional near‑infrared spectroscopy detects hemodynamic responses linked to neural activity.
Correct answer is: fNIRS
Q.74 What is a major benefit of using wireless EEG headsets for BCI applications?
Unlimited battery life
Reduced motion constraints and increased user comfort
Higher signal fidelity than wired systems
Elimination of all artifacts
Explanation - Wireless setups enhance mobility, though they may trade off a bit of signal quality.
Correct answer is: Reduced motion constraints and increased user comfort
Q.75 Which of the following is a recognized standard for safety testing of implanted neural devices?
ISO 13485
IEC 60601‑1‑10 (Neurostimulation)
IEEE 802.11ac
FDA 510(k) for software only
Explanation - IEC 60601‑1‑10 provides guidelines for safety and performance of neurostimulation equipment, including BCIs.
Correct answer is: IEC 60601‑1‑10 (Neurostimulation)
Q.76 When a BCI system uses “adaptive classifiers”, it means:
The classifier updates its parameters during use based on incoming data
The system changes the electrode positions automatically
The user must manually adjust the decision thresholds
The hardware adjusts its power consumption
Explanation - Adaptive classifiers learn from ongoing data to maintain performance despite signal variability.
Correct answer is: The classifier updates its parameters during use based on incoming data
Q.77 Which of the following is a typical characteristic of an invasive microelectrode array like the Utah array?
Contains 1000+ electrodes spaced millimeters apart
Provides single‑unit (neuron) level recordings
Requires no surgical implantation
Operates solely on wireless power
Explanation - The Utah array can record spikes from individual neurons, offering high spatial and temporal resolution.
Correct answer is: Provides single‑unit (neuron) level recordings
Q.78 Which of the following is a major challenge for BCIs that aim to decode speech directly from the brain?
Limited battery capacity of headsets
Complexity of mapping neural activity to phonemes or words
Inability to record any brain signals during speech
Excessive weight of the device
Explanation - Speech decoding requires fine‑grained models linking cortical activity to language elements, which is computationally intensive.
Correct answer is: Complexity of mapping neural activity to phonemes or words
Q.79 Which of the following best describes “neurofeedback” in the context of BCI training?
Providing the user with real‑time visual or auditory cues about their brain activity to encourage self‑regulation
Automatically adjusting the amplifier gain
Recording the user’s heart rate
Delivering electrical stimulation to the brain
Explanation - Neurofeedback helps users learn to modulate specific brain rhythms, improving BCI control.
Correct answer is: Providing the user with real‑time visual or auditory cues about their brain activity to encourage self‑regulation
Q.80 In BCI research, the term "subject‑specific model" indicates:
A model that works equally well for all participants
A classifier trained and tuned for data from a single individual
A universal algorithm that does not require training
A model that only uses generic population data
Explanation - Subject‑specific models capture idiosyncratic EEG patterns, often yielding higher accuracy than generic models.
Correct answer is: A classifier trained and tuned for data from a single individual
Q.81 Which of the following is a reason why BCI research often uses simulated data before testing on humans?
To avoid any cost associated with hardware
To evaluate algorithms under controlled conditions and reduce ethical concerns
Because simulated data is more accurate than real data
To bypass regulatory approval
Explanation - Simulations allow rapid testing while ensuring safety and ethical compliance before human trials.
Correct answer is: To evaluate algorithms under controlled conditions and reduce ethical concerns
Q.82 Which of the following best explains why BCIs that rely on SSVEP generally achieve higher information transfer rates than those using motor imagery?
SSVEP signals are larger in amplitude and have a clear frequency signature
Motor imagery does not produce any EEG changes
SSVEP requires fewer electrodes
Motor imagery is only possible in children
Explanation - The strong, frequency‑locked response in SSVEP makes detection faster and more reliable, boosting ITR.
Correct answer is: SSVEP signals are larger in amplitude and have a clear frequency signature
Q.83 Which of the following is an example of a BCI‑controlled assistive device?
Smartphone voice assistant
Eye‑gaze tracking mouse
Powered wheelchair driven by EEG commands
Bluetooth speaker
Explanation - BCI‑controlled wheelchairs translate brain commands into navigation actions, aiding mobility.
Correct answer is: Powered wheelchair driven by EEG commands
Q.84 Which of the following is a typical method for synchronizing stimulus presentation with EEG recording in a P300 speller?
Using a shared hardware trigger line
Relying on the user’s eye movements
Randomly varying stimulus intervals
Adjusting the room lighting
Explanation - A hardware trigger ensures precise timing between visual events and EEG acquisition for accurate epoching.
Correct answer is: Using a shared hardware trigger line
Q.85 Which of the following is a common source of "baseline drift" in EEG recordings?
Electrode polarization over time
High‑frequency muscle activity
Ambient temperature changes
Bluetooth latency
Explanation - Slow changes in electrode‑skin interface potentials cause low‑frequency drift that must be removed.
Correct answer is: Electrode polarization over time
Q.86 In BCI literature, the term "classifier confidence" usually refers to:
The voltage level of the EEG signal
The probability estimate that the classifier’s output is correct
The physical size of the electrode array
The speed of data transmission
Explanation - Confidence scores help decide whether to accept a command or request additional evidence.
Correct answer is: The probability estimate that the classifier’s output is correct
Q.87 Which of the following best describes the concept of "brain‑computer fusion"?
Merging two BCI devices into one
Combining multiple brain signal modalities (e.g., EEG + fNIRS) to improve performance
Using brain signals to power a computer
Physically attaching a computer chip to the brain
Explanation - Fusion leverages complementary information from different neuroimaging techniques for more robust BCIs.
Correct answer is: Combining multiple brain signal modalities (e.g., EEG + fNIRS) to improve performance
Q.88 Which of the following is a typical ethical guideline for BCI research involving human participants?
Ensuring informed consent and the right to withdraw
Providing participants with free laptops
Requiring participants to have prior BCI experience
Using only male participants to reduce variability
Explanation - Ethical standards demand that participants understand the study, its risks, and can stop participation at any time.
Correct answer is: Ensuring informed consent and the right to withdraw
Q.89 What is the main reason for using a “band‑pass filter” (e.g., 1‑40 Hz) in EEG preprocessing for BCIs?
To remove both low‑frequency drift and high‑frequency noise
To amplify the EEG signal
To convert analog signals to digital
To increase electrode impedance
Explanation - Band‑pass filtering isolates the frequency range where most EEG information resides while discarding artifacts.
Correct answer is: To remove both low‑frequency drift and high‑frequency noise
Q.90 Which of the following best illustrates the concept of "closed‑loop neurostimulation"?
Delivering electrical pulses based on real‑time detection of pathological brain activity
Providing continuous stimulation regardless of brain state
Using a fixed‑schedule stimulation protocol
Applying stimulation only during sleep
Explanation - Closed‑loop systems adjust stimulation parameters in response to ongoing neural signals, enhancing efficacy and safety.
Correct answer is: Delivering electrical pulses based on real‑time detection of pathological brain activity
Q.91 Which of the following is a potential advantage of using a "cloud‑based" BCI processing platform?
Eliminates the need for any local hardware
Provides scalable computational resources for complex algorithms
Guarantees zero latency
Ensures 100 % data privacy
Explanation - Cloud platforms can run heavy machine‑learning models without requiring powerful on‑device processors.
Correct answer is: Provides scalable computational resources for complex algorithms
Q.92 Which of the following statements about “brain‑controlled drones” is true?
They rely exclusively on invasive electrodes
They have been demonstrated using EEG‑based motor‑imagery control
They require users to speak commands
They are currently prohibited by aviation authorities
Explanation - Research prototypes have used EEG motor‑imagery to steer quadrotor drones, showcasing BCI control of aerial platforms.
Correct answer is: They have been demonstrated using EEG‑based motor‑imagery control
Q.93 What does the term "neural decoding" refer to in BCI research?
Translating recorded neural activity into intended commands or information
Increasing the signal strength of electrodes
Measuring the temperature of brain tissue
Encoding visual stimuli into neural patterns
Explanation - Neural decoding is the core process that maps brain signals to user intents for BCI output.
Correct answer is: Translating recorded neural activity into intended commands or information
Q.94 Which of the following is a common method to evaluate the robustness of a BCI system across different sessions?
Cross‑session validation
Increasing electrode size
Using a single‑session training set only
Ignoring noise in the data
Explanation - Cross‑session validation tests whether a model trained on one session maintains performance on later sessions.
Correct answer is: Cross‑session validation
Q.95 In a BCI experiment, the user’s brain activity is recorded while they imagine moving their right hand. Which electrode location (according to the 10‑20 system) is most likely to show the strongest desynchronization?
O1
Fz
C3
P4
Explanation - C3 lies over the left motor cortex, which controls the right hand; it typically shows mu rhythm desynchronization during right‑hand motor imagery.
Correct answer is: C3
Q.96 Which of the following best describes the purpose of a "ground truth" label in BCI data collection?
The exact timing of stimulus onset
The known intended command or mental task performed by the user during each trial
The voltage level of the EEG signal
The battery level of the recording device
Explanation - Ground truth provides the reference labels needed to train and evaluate classifiers.
Correct answer is: The known intended command or mental task performed by the user during each trial
Q.97 Which of the following is a major factor limiting the scalability of invasive BCI deployments in clinical settings?
The need for wireless connectivity
Surgical risks and long‑term biocompatibility concerns
The lack of any commercial BCI software
Inability to record any brain activity
Explanation - Implantation surgery and chronic tissue response are significant barriers to widespread clinical adoption of invasive BCIs.
Correct answer is: Surgical risks and long‑term biocompatibility concerns
Q.98 Which of the following best explains why high‑frequency (gamma) EEG activity is more challenging to decode for BCIs?
Gamma activity is too slow to be useful
It is often of lower amplitude and more susceptible to muscle artifacts
Gamma waves are only present during sleep
Gamma signals are not detectable with current hardware
Explanation - Gamma band signals have small amplitudes and can be contaminated by EMG, making reliable extraction difficult.
Correct answer is: It is often of lower amplitude and more susceptible to muscle artifacts
Q.99 In a BCI that uses the "steady‑state visual evoked potential" (SSVEP) paradigm, what determines the command the user selects?
The frequency of the flickering stimulus the user focuses on
The color of the stimulus
The user's heart rate
The ambient room temperature
Explanation - Each command is linked to a distinct flicker frequency; the EEG shows a peak at that frequency when the user attends to it.
Correct answer is: The frequency of the flickering stimulus the user focuses on
Q.100 Which of the following is an advantage of using a “convolutional neural network” (CNN) for EEG‑based BCI classification?
CNNs inherently handle temporal sequences better than other networks
CNNs can automatically learn spatial patterns from multi‑channel EEG data
CNNs require no training data
CNNs eliminate the need for any preprocessing
Explanation - CNNs exploit local spatial correlations across electrodes, reducing the need for handcrafted feature extraction.
Correct answer is: CNNs can automatically learn spatial patterns from multi‑channel EEG data
Q.101 Which of the following best describes the purpose of a “reference electrode” in EEG acquisition?
To provide a stable baseline potential for differential measurement
To transmit data wirelessly
To generate the EEG signal
To charge the device battery
Explanation - The reference electrode serves as a common point against which all active electrodes are measured.
Correct answer is: To provide a stable baseline potential for differential measurement
Q.102 What is the typical duration of a single trial in a motor‑imagery BCI experiment?
10‑20 ms
100‑200 ms
1‑2 seconds
5‑10 seconds
Explanation - Trials are usually a few seconds long to allow sufficient brain activity for reliable classification.
Correct answer is: 1‑2 seconds
Q.103 Which of the following is a major consideration when designing a BCI for people with severe motor impairments?
Ensuring the system uses high‑frequency visual flickers
Providing flexible, low‑effort interaction methods such as passive BCIs
Requiring rapid eye movements
Using large, heavy headsets
Explanation - Passive BCIs can infer user state without requiring explicit mental tasks, reducing effort for users with limited mobility.
Correct answer is: Providing flexible, low‑effort interaction methods such as passive BCIs
Q.104 Which of the following is a typical method for reducing the dimensionality of EEG data before feeding it into a classifier?
Linear Discriminant Analysis (LDA)
Discrete Fourier Transform (DFT)
Common Average Referencing (CAR)
Band‑stop filtering
Explanation - LDA projects data onto a lower‑dimensional space that maximizes class separability, often used as a classifier and dimensionality reduction tool.
Correct answer is: Linear Discriminant Analysis (LDA)
Q.105 Which of the following is a key challenge when using BCIs for continuous control (e.g., moving a cursor smoothly)?
Maintaining a constant voltage level
Achieving low latency and high accuracy simultaneously
Ensuring the user wears a bright LED cap
Using only binary classification
Explanation - Continuous control demands fast response while preserving precise command prediction, a demanding trade‑off.
Correct answer is: Achieving low latency and high accuracy simultaneously
Q.106 What does the term "brain‑computer symbiosis" imply for future BCI development?
A mutual adaptation where both the user and the algorithm continuously improve each other’s performance
Merging the hardware of the brain and computer into a single chip
Using brain tissue as a power source
Eliminating the need for any external device
Explanation - Symbiosis emphasizes co‑learning, with the system adjusting to the user and the user adapting to the system.
Correct answer is: A mutual adaptation where both the user and the algorithm continuously improve each other’s performance