Advanced techniques and research methods (2)

Question 1

Name five challenges faced by cognitive neuroscience methods.

Answer 1

1. Ethical constraints.
2. Localisation of brain functions.
3. Modular vs. network organisation of the brain.
4. Invasive vs. non-invasive methods.
5. Cost effectiveness.

Question 2

Describe the single test approach to neuropsychological testing.

Answer 2

• Specific to an area of the brain.
• Proved unsuccessful because no single test could be developed that would be sensitive to all the varied and complex psychological symptoms.

Question 3

Describe the fixed neuropsychological batteries approach to neuropsychological testing.

Answer 3

• Involves a comprehensive set of tests rather than a single test.

Question 4

Describe the flexible neuropsychological batteries approach to neuropsychological testing.

Answer 4

• Aims to characterise the nature of the psychological deficits of each brain-damaged patient.
• Begins with a common battery of tests to provide an indication of the general nature of the symptoms.
• Then a series of tests is customised to each patient to characterise the general symptoms.

Question 5

Describe the recording method of animal models. (4)

Answer 5

• Small electrodes implanted into the axon or outside the axon membrane.
• Measures the number of action potentials per second and the behaviour.
• Records neural activity (but doesn’t stimulate it). - Invasive technique.

Question 6

Describe the stimulation technique of animal models.

Answer 6

Weak current pulses increase firing of neurons. Can elicit behavioural responses.

Question 7

Describe the lesions technique of animal models.

Answer 7

Part of the brain is damaged, destroyed or inactivated to try determine the functions of the lesioned structure.

Question 8

What is the goal of reverse inference?

Answer 8

To infer the likelihood of a particular mental process from a pattern of brain activity.

Question 9

What is temporal resolution?

Answer 9

Temporal resolution is the time needed to acquire the data to generate an image.

Question 10

What is an EEG and how does it work?

Answer 10

• The EEG is a measure of the gross electrical activity of the brain.
• It is recorded through large electrodes by a device called an EEG machine.
• It is the sum of the excitatory postsynaptic potential (EPSP) and inhibitory postsynaptic potential (IPSP) generated by populations of neurons.

Question 11

What is an ERP and how does it work?

Answer 11

• Event-related potentials are brain waves generated following the presentation of stimuli.

Question 12

What does an MEG measure?

Answer 12

Magnetoencephalography measures electrical currents generated by magnetic fields in the brain.

Question 13

List the three methods with high temporal resolution.

Answer 13

1. EEG.
2. ERP.
3. MEG.

Question 14

What is spatial resolution?

Answer 14

Spatial resolution refers to the smallest feature that a scanner can detect to allow high accuracy.

Question 15

Describe the MRI process.

Answer 15

• MRI is a structural brain-imaging procedure in which high-resolution images are constructed from the measurement of radio-frequency waves
• Waves are emitted by hydrogen atoms as they align with a powerful magnetic field.
• This is a non-invasive method.

Question 16

Describe the DTI process.

Answer 16

• DTI (diffusion tensor imaging) looks into the white matter integrity of the brain.
• It allows the reconstruction of tracts that connect brain regions.
• It is a method of identifying those pathways along which water molecules rapidly diffuse.

Question 17

List the four methods with high spatial resolution.

Answer 17

1. MRI.
2. DTI.
3. fMRI.
4. PET.

Question 18

Describe the process of fMRI.

Answer 18

• Functional MRI measures the blood-oxygen-level-dependent (BOLD) response from brain regions.
• Those more active will generate stronger BOLD signals.
• It is often used to determine if a brain is dysfunctional.

Question 19

Describe the process of PET.

Answer 19

• Positron emission tomography measures regional cerebral blood flow after injecting radioactive substances.
• Radiations can be detected using brain scanners.
• This is a very invasive technique.

Question 20

What would increased stress and arousal show in an ECG, EMG and a SCR?

Answer 20

ECG – Faster heart beats.
EMG – Increased muscular tension.
SCR – Increased sympathetic activity.

Question 21

What is an advantage and disadvantage of eye-tracking technology?

Answer 21

+ Excellent spatial and temporal resolution; non-invasive, becoming more portable and less expensive.
- Because a participant has fixated on information, doesn’t necessarily mean they have used the information.

Question 22

What technique does the study of connectome rely on?

Answer 22

DTI.

Question 23

EEGs produce wave forms that can be correlated with what four psychological states?

Answer 23

• Arousal.
• Relaxation.
• Sleep.
• Deep sleep.