Artikelen + lecture week 1

Question 1

What is brain-computer interface (BCI)?

Answer 1

A direct online connection between the brain and a machine is made. Mental activity is measured and used directly to control a computer interface (e.g., a wheelchair)

Question 2

What are the components of the the components of BCI cycle?

Answer 2

1. Measurment
2. Preprocessing
3. Feature extraction
4. Prediction
5. Output
6. Stimulation
7. Modality

Question 3

The ideal BCI task should contain the following:

Answer 3

• Easy to perform with little effort (prevents fatigue).
• Reliable and fast interpretation of the signals.
• Easy to control and fast to switch.
• Output is user-friendly and the feedback is effective

Question 4

What are examples of BCI tasks?

Answer 4

Perceptual tasks (e.g., selective attention to one stimulus of a set of stimuli), and imagery tasks (e.g., motor imagery or music imagery)

Question 5

What is the difference between synchronous (or ‘cue-based’) BCI
systems and asynchronous (or ‘self-paced’) BCI systems?

Answer 5

In synchronous BCI systems, the response is time locked to the stimulus. In asynchronous BCI system, the system has to figure out exactly when a response happens

Question 6

Which system is more natural and closer related to daily living, but it is much harder to realize such a BCI system, synchronous or asynchronous?

Answer 6

Asynchronous

Question 7

What are non-invasive measuring methods?

Answer 7

• EEG and MEG; these reflect the average activity of dendritic currents in a large number of cells.
• fMRI measures changes in blood haemoglobin concentrations associated with neural activity.
• Near-infrared spectroscopy (NIRS): measures the different resonance properties of oxygenated and deoxygenated haemoglobin.

Question 8

What are invasive measuring methods? (name examples)

Answer 8

• Involves implanting of electrodes on/in the neocortex.
• Electro-corticogram (ECoG): ECoG is often used in epileptic patients to determine source of epileptic attacks in the brain.
• Signal-to-noise ratio = a measure for the quality of a signal in which there is a (hindering) noise.
• Micro-electrodes (ME) or many micro electrodes (a ‘micro-electrode array’ or ‘MEA’). These micro-electrodes can record multiple forms of electrical potentials.

Question 9

What is a ‘signature’?

Answer 9

A set of characteristics that can be found in a brain signal and can be uniquely described to a specific mental process or state. And example of a signature is that of sleep

Question 10

The ‘signatures’ that have been proven useful for BCI are evoked responses and induced responses. What are those?

Answer 10

Evoked responses: time- and phase-locked to an event.
Induced responses: not phase-locked. The power, rather than the phase, is time locked to the stimulus

Question 11

What is the preprocessing stage?

Answer 11

During this stage, measured brain signals are transformed with the aim to maximize signal-to-noise ratio and thus maximizing the probability of a correct brain state identification

Question 12

The most used types of preprocessing are:

Answer 12

• Artefact detection: finding confounding signals from sources outside the brain (e.g., eye and muscle artefacts) and then remove these confounding signals.
• Spectral filtering: removing noise signals by combining signals to focus on or reject signals based upon their position in the brain.
• Spatial filtering: identifying statistically independent sources of activity

Question 13

What is the feature extraction stage (BCI)?

Answer 13

‘Feature extraction’ means that the temporal (time) and spectral (power) features of a signal are used to characterize the signal of interest

Question 14

Which BCI stages are needed to get the raw signals ‘ready’ for predicting outcomes

Answer 14

Preprocessing and feature extraction

Question 15

The ease or difficultness of making a prediction in the prediction phase/ classification stage depends on?

Answer 15

The classifier, the number of extracted features, the amount of training data and the experimental paradigm.

Question 16

What happends in the output stage?

Answer 16

In this stage, information is generated that will control an output device. In this stage, the user gets feedback on his/her predicted intention.

Question 17

What is computer-based assessment?

Answer 17

Any instrument that utilizes a computer, digital tablet, handheld device, or other digital interface instead of a human examiner to administer, score, or interpret tests of brain function and related
factors relevant to questions of neurologic health and illness

Question 18

Algorithms can be used for adaptive testing (algorithm selects future test items based on prior performance) and also for?

Answer 18

Algorithms can also be used to detect characteristic deficits/complaints of specific disorders, thus
assisting the neuropsychologist in making a diagnosis.

Question 19

VR testing may provide more distractions; a benefit of this is that it improves the …

Answer 19

Ecological validity

Question 20

Where was the Virtual Multiple Errands Tests (VMET) developed for?

Answer 20

To assess frontal lobe lesions

Question 21

True or false: one should not just assume that a VR version of an analog test measures exactly the same cognitive constructs as the analog version, because digitizing an analog test can alter the nature of the task

Answer 21

True

Question 22

What are some strengths of computer-based cognitive assessment?

Answer 22

• More detailed measures
• Algorithm design.
• Increased ease of administration and standardization (e.g., less errors in scoring and interpretation).
• Easy to use
• VR provides the possibility to customize the virtual environment to specific target populations and to influence environmental stimuli (improved ecological validity).
• Additional cognitive and behavioral information can be obtained and data can be obtained more precisely.
• Computer-based assessment could improve inter-rater reliability.
• Computer-based assessment enables longitudinal monitoring of daily activity performance

Question 23

What are some weaknesses of computer-based cognitive assessment?

Answer 23

• Variations in computer hardware (e.g., speed of a computer).
• Normdata of paper-and-pencil tests are not directly transferable to computer tests
• Validity and reliability need to be proven
• Physiological concerns about VR use (e.g., motion sickness).
• Using VR technology is new for most patients and the novelty might alter behavior.
• VR is subject to great individual variability (e.g., differences in computer experience, learning and adaptation, enjoyability of the experience).
• VR is a relatively high-cost form of assessment.
• Privacy issues with data storage.

Question 24

Real-time data collection is also known as? (EMA)

Answer 24

Ecological momentary assessment

Question 25

What are some factors that contributed to the limited adoption of new technology in neuropsychology?

Answer 25

- More focus on technical challenges than on technical advantages - Concerns about clinicians and patients lacking familiarity with new technology - The role of trained examiners (who evaluate/interpret test results) might diminish - Lack of innovation in the tests that were digitized - For many digitized tests, there were no psychometric studies performed, so little was known about the concurrent validity of computer measures - Very little quantity and quality of normative data for computer measures - Often, more effort was put into the technology itself rather than in the psychometric properties of tests

Question 26

Reasons why neuropsychologists did not use computer testing:

Answer 26

- Financial costs associated with purchasing computer tests - Lack of good normative data - Concerns about test utility or validity

Question 27

True or false: It is harder to assess nonverbal learning and free recall memory than verbal fluency and speech recognition

Answer 27

True

Question 28

What are benefits of digital tests?

Answer 28

- the built-in standardization of administration of the test (increases reproducibility and reliability) - the ability to include the Item Response Theory (IRT)

Question 29

What is the the Item Response Theory (IRT)?

Answer 29

Item-level performance of the patient is tracked and based on the patient’s performance, the computer calculates which items should be answered next by the patient (so that the patient does not have to answer a lot of very simple items if it is already clear that the patient’s performance exceeds that basic level)

Question 30

A condition for Item Response Theory to work, is that a test needs a very small/ large item bank to draw items from. This would have the benefit that multiple alternate forms of the test could be developed and would also be beneficial for .... and re-evaluations

Answer 30

Large Longitudinal monitoring

Question 31

Points of consideration for computerized scoring:

Answer 31

- Computers are more rigid and less flexible than analog measures (computers might not recognize when a patient does not understand task instructions) - It is important to maintain the security and confidentiality of a patient’s data - The volume of data generated by computer measures is much greater than volume generated by analog measures.

Question 32

What are disadvantage/ points of consideration for remote testing?

Answer 32

- It limits the input and response of the patient. A good remote assessment would require standardization and appropriate normative data

Question 33

What are advantages of continual/ passive data-capture? = a methodology which often takes place without the participants awareness

Answer 33

- The amount of data that can be gathered on a patient is massive (trough phones and smartwatches) - Behavior data is captured in real-time and with additional information about the local environment it would even be possible to link behavior to the context (ecological validity)

Question 34

Points of consideration for continual data-capture:

Answer 34

- Some devices (such as tablets) may be used by multiple users. - More knowledge is needed on how to link continuously captured data to analog measures. - Patients will have to give informed consent

Question 35

What are some goals where BCI can be used for?

Answer 35

- Moving a wheelchair/robot arm/cursor on a screen - Communicate through letters and words - Control environmental factors.

Question 36

In the research of Ineke: ..... benefits metric processing (where the objects were placed) and memory of the order in which the objects were placed along the route

Answer 36

Locomotion = the power of moving from place to place

Question 37

What is the goal of treatment/ rehabilitation for patients?

Answer 37

More participation in daily life

Question 38

What is the difference between compensation and restoration?

Answer 38

Compensation: when a function is lost or reduced, another function or strategy is used instead Restoration: when a function is lost or reduced, trying to improve that function

Question 39

What are some ethical considerations for VR?

Answer 39

- It should be made clear what the differences are between the real and the virtual situation. - Social interaction: there should be sufficient social interaction with the patient. - Level of understanding of the patient should be good enough.