Ways of investigating the brain

Not on test!!

fMRI, EEG, ERPs and (other) post-mortem examinations

what are the 4 ways to investigate the brain?

1. Changes in blood oxygenation levels. Creates a 3D map of the brain to show areas which are active. activation maps

2. More oxygen. This increases blood flow which is directed at the active part of the brain. Haemodynamic response.

How fMRI’s investigate the brain:

1. It works by detecting what? What does the fMRI create? What is this creation called?

2. When a brain is active it consumes what? What does this increase? What is this known as?

Haemodynamic response

what is it called in an fMRI when increased blood flow is directed at the active part of the brain?

activation maps

what is it called in an fMRI when the machine creates a 3D map of the brain?

1. Electrical activity within the brain. This is done by electrodes that are fixed on the scalp. There are 4 different types of brain waves recorded: alpha, beta, delta and theta.

2. Information is processed in the brain as electrical activity (through action potentials and nerve impulses).

3. Small electric charges, these are graphed as patterns.

4. The brainwave patterns that are generated from millions of neurons. This provides an overall account of brain activity.

How EEG’s investigate the brain:

1. What do they measure, by what? How many different types of brain waves are recorded and what are they called?

2. What does the EEG assume? How is this assumption measured?

3. What is detected? What happens next?

4. What does the recording represent? What does this provide?

1. Intensity of the activity, and the speed of the activity.

2. Diagnostic tools. This is because unusual arrythmic patterns of activity may indicate neurological abnormalities.

3. Epilepsy, Alzheimer’s disease and disorders of sleep.

How EEG’s investigate the brain: what can they tell us?

1. What does amplitude and frequency test?

2. What are EEG’s used for? Why is this and what may it indicate?

3. What are examples of what the scan may indicate?

1. Teasing out and isolating specific neural responses. These are associated with sensory, cognitive, and motor events.

2. Filters out responses only leaving these responses related to a specific task.

3. Psychologists show a participant a stimulus (e.g. picture/ sound). Electrical activity is measured in the brain for that particular stimulus. This happens while the participant is wearing a skull cap.

4. This leaves the event-related potentials which is measured on a computer system.

5. Many specific types of responses e.g. attention/ memory.

How ERPs investigate the brain:

1. What are ERPs a way of doing? What are these associated with?

2. What does it filter out?

3. What does the procedure involve - what do they show the participant? What is measured? What does the participant wear?

4. What does this leave and how is this measured?

5. What do ERPs reveal?

1. EEG is a recording of general brain activity, linked to states such as sleep and arousal.

2. Specific stimuli

What is the difference between EEGs and ERPs?

1. EEG is a recording of what, linked to states such as what?

2. ERPs work by what being presented to the participant?

the types of brain waves that are triggered by particular events. This is measured on a computer system.

what are event-related potentials?

1. Involves the analysis of a person’s brain following their death.

2. A rare disorder. May have experienced unusual deficits in mental processes or behaviour during their lifetime.

How Post-mortem examinations investigate the brain:

1. What does this technique involve?

2. What do people who often have a post-mortem have? What does this mean that they have experienced?

invasive

physical alteration by entering the body

non-invasive

no breaking of the skin is involved. The participant may experience some discomfort, but no physical harm comes to them.

temporal resolution

the precision of measurement in regards to time

spatial resolution

refers to the smallest feature (or measurement) that a scanner can detect, and is an important feature of brain scanning techniques. Greater (this feature) allows psychologists to discriminate between different brain regions with greater accuracy.