Ways of studying the brain

Question 1

Spatial resolution

Answer 1

Spatial resolution is the degree of accuracy that a technique achieves when examining brain activity. It is the accuracy with which the exact areas of brain structures and activity are identified.

Question 2

Temporal resolution

Answer 2

Temporal resolution is the degree of accuracy in determining brain activity over time that the technique provides. It relates to when the activity virtually occurred and how accurately the technique can record this information.

Question 3

What is a post Mortem?

Answer 3

Technique involving the analysis of a person’s brain following their death

Areas of the brain are examined to establish the likely cause of a deficit or disorder that the person experienced in life e.g trauma

This may also involve comparison with a neurotypical brain in order to assess the extent of the difference

Question 4

What area was discovered using post mortem?

Answer 4

Broca’s areas (responsible for language production) - patient called Tan, who could only say Tan (expressive aphasia).

Damage in an area of the frontal lobe was found after Tans death

Question 5

EVALUATION:
The high spatial resolution of post mortem allows…

Answer 5

the study of microscopic brain structures down to the neuronal level

Question 6

EVALUATION:
As post mortem is not conducted on the living brain, unusual behaviour in life and damage found is correlational. However…

Answer 6

theories are then generated that can be tested with other, experimental techniques

Question 7

EVALUATION:
Post mortem techniques have been significant in the historical development of…

Answer 7

psychology’s understanding of brain functioning such as the discover of language centres

Question 8

EVALUATION:

Strength of post mortems - post mortems are used in localisation and medical research

Limitation of post mortems - knowing causation and ethics

Answer 8

Broca and Wernicke both relied on post mortem studies. Used to link HM’S memory deficits to damage in his brain - continue to provide useful info

Observed damage in brain may not be linked to deficits under review. They raise ethical issues of consent after death - challenges usefulness in psychological research

Question 9

What does fMRI stand for?

Answer 9

Functional magnetic resonance imaging

Question 10

What is a fMRI?

Answer 10

HIGHLIGHTS ACTIVE AREAS OF THE BRAIN

Detects changes in both blood oxygenation and flow that occur due to neural activity in specific brain areas

When a brain area is more active it consumes more oxygen and blood flow is directed to the active area (haemodynamic response)

fMRI produces a 3DS image - shows parts of the brain are active - must be involved in particular mental processes

Question 11

EVALUATION:
fMRI has good spatial resolution of approx 1mm. Precisely identifying…

Answer 11

active brain regions and patterns of activation over time while participants complete experimental conditions

Question 12

EVALUATION:
fMRI is non invasive and…

Answer 12

a safe technique for experiments compared to options that use radiation i.e PET scanners

Question 13

EVALUATION:
Poor temporal resolution as one image is taken…

fMRI machines are expensive to…

Answer 13

every few seconds and delay blood flow after activity. This means many brain processes like vision are too fast to study

build and operate. Also as the participant needs to be still, experiments with body movement are not possible

Question 14

What does EEG stand for?

Answer 14

Electroencephalogram

Question 15

What is an EEG?

Answer 15

SHOWS OVERALL ELECTRIC ACTIVITY

It measure electrical activity within the brain via electrodes using a skull cap

Scan recording represents the brainwave pattern generated from thousands of neurons - showing overall brain activity

Often used as a diagnostic tool - unusual arrthymic patterns of the brain activity -> indicate abnormalities such as epilepsy, tumours/ sleep disorders

Question 16

EVALUATION:
Historically important in understanding brain activity in areas such as…

Answer 16

sleep research and medical diagnosis

Question 17

EVALUATION:
Cheaper than alternatives such as fMRI and…

Answer 17

able to be used in experiments in which the participant moves

Question 18

EVALUATION:
Poor spatial activity as…

Answer 18

pattern is sum of a large number of neurons in the cortex under the electrode. So it is difficult to know exact source of neural activity - cannot distinguish activity of different but adjacent neurons

Also cannot detect activity deep within the brain

Question 19

What does ERP stand for?

Answer 19

Event related potentials

Question 20

What is an ERP

Answer 20

BRAINWAVES RELATED TO PARTICULAR EVENTS

Event-related potentials (ERPs) are very similar to EEGs because they also use electrodes and record the tiny electrical changes in the neurons of the brain.

The difference is that researchers present participants with a stimulus many times, and each wave response is added to a pool of data.

This creates a smooth activation curve of the collected data, called statistical averaging

Question 21

EVALUATION:
ERP’s allow researchers to…

Answer 21

isolate and study how individual cognitive processes take place in the brain, while EEG’s record general brain activity

Question 22

EVALUATION:
Like EEG’s, ERP’s have good temporal (compared to fMRI) - resolution with a millisecond sampling rate - freq used in cognitive research BUT…

Answer 22

very poor spatial resolution. Some processes cannot be studies studied by ERP as they cannot be presented a large number of times with the same response

Question 23

EVALUATION:

Limitation of ERP’s - lack of standardisation and background ‘noise’

Answer 23

Lack of standardisation makes it difficult to confirm findings in studies involving ERPs - background noise and extraneous material must be completely eliminated - these issues are a problem, may not always be easy to achieve