BIOPSYCHOLOGY - ways of studying the brain

Question 1

what is functional magnetic resonance imaging (fMRI)?

Answer 1

A method used to measure brain activity while the person is performing a task.

Detects radio waves from changing magnetic fields = enabling researchers to detect which regions of the brain are rich in O2 and thus are active.

Question 2

what is neural activity and mapping changes in blood flow

Answer 2

As a particular area of the brain becomes more active = consumes more oxygen, so blood flow is directed to the active area.

fMRI produces 3D images= showing which parts of the brain are involved in particular mental processes.

Question 3

evaluate the use of fMRI.

Answer 3

+ does not rely on the use of radiation = risk free, non invasive and straightforward to use.
+ produces images which has high spatial resolution = provides a clear picture of how the brain activity is localised
= fMRI can safely provide a clear picture of brain activity

• expensive compared to other neuroimaging techniques and poor temporal resolution because there is a 5 second time lag behind the image on screen = doesn’t represent moment to moment brain activity.

Question 4

what is electroencephalogram (EEG)?

Answer 4

A record of the tiny electrical impulses produced by the brains activity, measured by electrodes that a fixed to an individuals scalp using a skull cap.

The scan recording represents the brainwave patterns that are generated from the action of thousands of neurons.

Question 5

evaluate the use of EEG?

Answer 5

+ useful in studying the stages of sleep and in the diagnosis of conditions such as epilepsy = a disorder that is characterised by random bursts of activity in the brain.
+ high temporal resolution = can detect brain activity at a resolution of a single millisecond

• information is received from thousands of neurons = EEG signal is not useful for pinpointing the exact source of neural activity= does not allow researchers to distinguish between activities originating in different but adjacent locations.

Question 6

what are event related potentials (ERP)?

Answer 6

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

Question 7

evaluate the use of ERP’s.

Answer 7

+ brings specificity to the measurement of neural processes.
+ As ERP’s are derived from EEG measurements, they have excellent temporal resolution compared to fMRI.
= ERP is used to measure cognitive functions and deficits such as the maintenance of working memory.

• lack of standardisation in ERP methodology between different research studies which makes it difficult to confirm findings
• back ground noise and other extraneous materials must be eliminated = not easy to achieve.

Question 8

what are post morterm examinations?

Answer 8

the brain is analysed after death to determine whether certain observed behaviours during the person’s lifetime can be linked to structural abnormalities in the brain.

Question 9

evaluate post morterm examinations.

Answer 9

+ Post Morterm evidence was vital in providing a foundation for early understanding of key processes in the brain. eg. Broca and Wernicke relied on post morterm studies to establish links between language brain and behaviour.

• observed damage to the brain may not be linked to the deficits under review but other unrelated trauma or decay.
• ethical issues of consent from individual before death
  = challenges the usefulness of PMS.