Ways of studying the brain

Question 1

What are the 4 ways of studying the brain?

Answer 1

1. fMRI (Functional Magnetic Resonance Imaging)
2. EEGs (Electroencephalogram).
3. ERPs (Event-Related Potentials).
4. Post- Mortem Examination

Question 2

What is

Question 3

What are the 4 ways of studying the brain?

Answer 3

1. fMRI (Functional Magnetic Resonance Imaging).
2. EEGs (Electroencephalogram).
3. ERPs (Event- Related Potentials).
4. Post- Mortem Examination

Question 4

What is an fMRI?

Answer 4

• A brain-scanning technique that measures blood flow in the brain when a person performs a task.
• Works on the basis that neurons in the brain which are most active (during a task), use the most energy.
• An fMRI creates a dynamic (moving) 3D map of the brain, highlighting which areas are involved in different neural activities.

Question 5

fMRI- more detail

Answer 5

• Deoxygenated haemoglobin has a different magnetic quality from oxygenated haemoglobin= this is what creates the map of the brain.
• fMRI images show approximately 1-4 seconds after it occurs and are thought to be accurate within 1-2 mm.
• An increase in blood flow is the response needed for more oxygen in that area of the brain when it becomes active (suggesting an increase in neural activity).

Question 6

Evaluation of fMRI (Invasive vs Non invasive)

Answer 6

• An advantage of fMRI is that it is non-invasive.
• Unlike other scanning techniques, for example and PET scan, fMRI does not use radiation or involve inserting instruments directly into the brain= therefore they are virtually risk free!
• Consequently, this should allow more patients/ ppts to undertake fMRI scans which could help psychologists to gather further data on the functioning human brain and therefore develop our understanding of localisation of function.

Question 7

Evaluation of fMRI (spatial resolution)

Answer 7

• fMRI scans have a good spatial resolution.
• SR refers to the smallest feature (or measurement) that a scanner can detect, and is an important feature of brain scanning techniques.
• Greater spatial resolution allows psychologists to discriminate between different brain regions with greater accuracy.
• fMRI scans have a spatial resolution of approximately 1-2 mm which is significantly greater than the other techniques (EEG, ERP, etc.).
• Consequently, psychologists can determine the activity of different brain regions with greater accuracy when using fMRI, in comparison to when using EEG and/or ERP.

Question 8

Evaluation of fMRI (temporal resolution)

Answer 8

• fMRI scans have poor temporal resolution.
• TR refers to the accuracy of the scanner in relation to time; or how quickly the scanner can detect changes in brain activity.
• fMRI scans have a temporal resolution of 1-4 seconds, which is worse than other techniques (EEG/ERP which have a TR of 1-10 milliseconds).
• Consequently, psychologists are unable to predict with a high degree of accuracy the onset of brain activity.

Question 9

Evaluation of fMRI (causation)

Answer 9

• fMRI scans do not provide a direct measure of neural activity.
• They simply measure the changes in blood flow and therefore it is impossible to infer causation (at a neural level).
• While any change in blood flow may indicate activity within a certain brain area, psychologists are unable to conclude whether this brain region is associated with a particular function.
• In addition, some psychologists argue that fMRI scans can only show localisation of function within a particular area of the brain, but are limited in showing the communication that takes place among the different areas of the brain, which might be critical to neural functioning.

Question 10

What is an EEG?

Answer 10

• An electroencephalogram works on the premise that information is processed in the brain as electrical activity in the form of action potentials or nerve impulses, transmitted along other neurons.
• EEG’s measure this electrical activity through electrodes attached to the scalp.
• Small electrical charges that are detected by the electrodes are graphed over a period of time, indicating the level of activity in the brain.

Question 11

EEGs + brain waves

Answer 11

There are four types of EEG patterns including:
- Alpha waves
- Beta waves
- Theta waves
- Delta waves

Each of these patterns also has two basic properties that psychologists can examine:
1. Amplitude= the intensity or size of the activity.
2. Frequency= the speed or quantity of the activity.

Question 12

EEGs- types of patterns

Answer 12

-EEG patterns produce two distinctive states; synchronised and desynchronised patterns.
- A synchronised pattern is where a recognised wave form can be detected, whereas a desynchronised is where no pattern can be detected.

• Fast, desynchronised patterns are usually found when awake and synchronised patterns are typically found during sleep.
• Real life app= furthermore, EEG scanning was responsible for developing our understanding of REM (dream) sleep, which is associated with a fast, desynchronised activity, indicative of dreaming.
• EEGs can also be used to detect illnesses like epilepsy and sleep disorders, and to diagnose other disorders that affect brain activity, like Alzheimer’s disease.