Scanning and other techniques

Question 1

fMRI

Answer 1

Functional Magnetic Resonance Imaging

Question 2

EEG

Answer 2

Electroencephalogram

Question 3

ERP

Answer 3

Event-related potentials

Question 4

fMRI works by…

Answer 4

detecting changes in the blood oxygenation and flow that occur as a result of neural (brain) activity in specific parts of the brain.

Question 5

fMRI: What happens when a brain area is more active?

Answer 5

It consumes more oxygen to meet its increased demand; the blood flow is directed to the active area producing 3D images showing which parts are involved in a particular mental process and has important implications for our understanding of localisation of function.

Question 6

fMRI: What does it enable the researchers to learn?

Answer 6

Detect which regions of the brain are rich in oxygen and thus are active.

Question 7

fMRI: strengths

Answer 7

Doesn’t rely on the use of radiation.
Virtually risk-free, non-invasive, and straightforward to use (if administered correctly).
Produces images with high spatial resolution - provides a clear image of how brain activity is localised.

Question 8

fMRI: limitations

Answer 8

Expensive.
Can only capture a clear image if the person stays perfectly still.
Poor temporal resolution - around 5 second time lag.
Only measures the blood flow in the brain and can’t home in on the activity of individual neurons, thus difficult to tell exactly what brain activity is being represented.

Question 9

EEG records…

Answer 9

electrical impulses produced by the brain’s activity, enabling it to diagnose certain conditions.

Question 10

EEG: how is electrical activity measured?

Answer 10

Via electrodes that are fixed to an individual’s scalp using a skull cap.

Question 11

EEG: the scan recording represents…

Answer 11

The brainwave patterns are generated from the action of millions of neurons, providing an overall account of brain activity.

Question 12

EEG: How is it used?

Answer 12

Used by clinicians as a diagnostic tool as unusual arrhythmic patterns of activity may indicate neurological abnormalities.

Question 13

EEG: strengths

Answer 13

Proved invaluable in the diagnosis of conditions.
Contributed much to our understanding of the stages involved in sleep.
Extremely high temporal resolution.
Accurately detect brain activity at a resolution of a single millisecond.

Question 14

EEG: weaknesses

Answer 14

Nature of information gathered - generalised.
Not useful for pinpointing the exact source of neural activity.
Doesn’t allow researchers to distinguish between activities originating in different but adjacent locations.

Question 15

ERP is the brain’s…

Answer 15

electrophysiological response to a specific sensory, cognitive, or motor event can be isolated through statistical analysis of EEG.

Question 16

ERP: What is filtered out of the EEG?

Answer 16

All extraneous brain activity from the original EEG is filtered out leaving only those responses that relate to a stimulus or task.

Question 17

ERP: What remains are ERPs…

Answer 17

Types of brainwaves triggered by particular events.

Question 18

ERP: Research has revealed…

Answer 18

Many different forms of ERP and how they are linked to cognitive processes.

Question 19

ERP: Strengths

Answer 19

Brings much more specificity to the measurement of nerual processes.
High temporal resolution.
Widespread use in measurement of cognitive functions and deficits.
Able to identify many different types of ERP and describe the precise role of cognitive functioning.

Question 20

ERP: Weaknesses

Answer 20

Lack of standardisation in methodology between different research studies making it difficult to confirm studies.
Gain pure data - eliminate background noise and extraneous material - not easy to achieve.

Question 21

Post-mortem examinations (PEMS)

Answer 21

The technique of analysis of a person’s brain following their death.

Question 22

PEMS: Who is more prone to being put through PEMS?

Answer 22

Individuals whose brains are subject to a post-mortem are likely to be those who have a rare disorder and have experienced unusual deficits in mental processes or behaviour during their lifetime.

Question 23

PEMS: What areas are damaged?

Answer 23

Areas of damage within the brain are examined after death as means of establishing the likely cause of the affliction the person suffered. This may also involve comparison with a neurotypical brain in order to ascertain the extent of the difference.

Question 24

PEMS: Strengths

Answer 24

Vital in providing a basis for an early understanding of key processes in the brain.
Broca and Wernicke relied on PEMS in establishing links between language, brain, and behaviour decades before neuroimaging ever become a possibility.
Improves medical knowledge.
Help generate hypotheses for further study.

Question 25

PEMS: Limitations

Answer 25

Observed damage may not be linked to deficits under review but to unrelated damage/trauma.
Raises ethical issues of consent from the patient before death - not be able to provide informed consent.