Ways of studying the brain

Functional Magnetic Resonance Imaging (fMRI)

Uses powerful magnets to detect changes in blood oxygenation in the brain. When a part of the brain is more active it uses more oxygen which requires more blood. This is called the haemodynamic response.

S fMRI

Non-invasive

High spatial resolution

Doesn’t rely on radiation

Can safely provide a clear picture of brain activity

W fMRI

Expensive

Poor temporal resolution (time lag of 5 seconds behind the image on screen and initial firing of neuronal activity

You have to stay completely still

May not fully represent brain activity

Electroencephalogram (EEG)

Measures electrical activity in the brain

Can help diagnose certain conditions of the brain

Electrodes are fixed to an individual’s scalp using a skull cap

Measures brainwave patterns

5 hours maximum sleep the night before

Asked to do activation exercises

S EEG

Useful in studying the stages of sleep and in the diagnosis of conditions like epilepsy, seen by random bursts of activity in the brain that can be detected on screen.

Can accurately detect brain activity at a resolution of a single millisecond

Shows the real-world usefulness of the technique

W EEG

The information is normally generalised based on thousands of neurons

Not useful for pinpointing the exact source of neural activity

Event-related potentials (ERPs)

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

S ERPs

More specificity to the measurement of neural processes than could be achieved using raw EEG data.

Temporal resolution compared to other techniques like fMRI.

Frequently used to measure cognitive functions and deficits like allocating attentional resources and the maintenance of working memory

W ERPs

Lack of standardisation between different research studies. Makes it difficult to confirm findings.

Harder to eliminate background noise and extraneous material completely.

Post-mortem examinations

A medical examination of a body after death.

Psychologists may wish to determine whether observed behaviours can be linked to particular features in the brain

S Post-mortem

Vital in providing a foundation for early understanding of key processes in the brain.

Broca and Wernicke relied on post-mortem studies in establishing links between language, brain and behaviour before neuroimaging became a possibility.

Used to study HM’s brain to identify areas of damage which were associated with his memory condition (See Multi-store model)

Continue to provide useful information

W Post-mortem

Causation. Observed damage to the brain may not be linked to a condition under review but to other unrelated trauma or decay.

Raise ethical issues of consent from the individual before death. Participants may not be able to give informed consent e.g. HM.

Challenges the usefulness of post-mortem studies.