ways of studying the brain

Functional magnetic resonance imaging: fMRIs

• When a brain area is active, it uses more oxygen.

• The fMRI detects this by measuring oxygen levels in the blood.

• More oxygen = more activity.

• The scanner creates images showing which brain areas "light up" during tasks (like thinking, moving, or feeling).

Electroencephalogram: EEGs

• Small sensors (electrodes) are placed on the scalp.

• These pick up tiny electrical signals made by brain cells (neurons) when they send messages.

• The signals are recorded as waves on a screen.

So, an EEG shows when brain activity happens, but not exactly where it's coming from.

It’s often used to study sleep, seizures, or brain disorders.

Event-related potentials ERPs

• Electrodes are placed on the scalp, just like in an EEG.

• A person is shown a stimulus (e.g. a word or picture).

• The EEG records the brain’s electrical activity linked to that exact moment.

• By repeating the stimulus and averaging the results, ERPs show brain responses to specific events.

So, an ERP helps us see how quickly and strongly the brain reacts to something.

post mortem examinations

• when a persons body including their brain is examined after they have died

• they can be used to see where damage had occured in the brain and how that might explain behaviour exhibited by the person prior to death.

ao3 FMRI (strength and limitation)

• One limitation of using an fMRI scan is that it has low temporal resolution. Although it shows where brain activity is happening, it measures changes in blood flow rather than direct neural activity, which takes several seconds. This means it cannot accurately capture the rapid timing of mental processes. Therefore, fMRI is less useful when studying fast cognitive activities such as decision making or attention.

• One strength of using an fMRI scan is that it provides objective and scientific data about brain activity. It measures changes in blood flow to different brain areas, allowing researchers to see which regions are active during specific tasks. This means results are not based on self-report or opinion, reducing researcher bias. Therefore, fMRI has high scientific credibility and can produce reliable evidence about how the brain functions.

ao3 EEG & ERP (strength and limitation)

• One strength of using EEG and ERPs is that they have excellent temporal resolution. They measure electrical activity in the brain in milliseconds, allowing psychologists to see brain responses almost instantly after a stimulus is presented. This is especially useful when studying fast cognitive processes such as attention, perception and language processing. Therefore, EEGs and ERPs provide highly accurate information about the timing of brain activity.

• One limitation of using EEG and ERPs is that they have poor spatial resolution. They can show when brain activity happens, but they are less accurate at identifying the exact area of the brain where the activity occurs. This is because the electrical signals are recorded from the scalp rather than directly from the brain. Therefore, EEGs and ERPs are limited in locating precise brain regions involved in behaviour.

ao3 post mortem (strength and limitation)

• One limitation of using post-mortem examinations is that findings may lack validity. Researchers study brains after death, often from individuals who suffered unusual illnesses or injuries, so the results may not represent normal brain functioning. In addition, it can be difficult to know whether observed abnormalities caused the behaviour or developed afterwards. Therefore, conclusions drawn from post-mortem research may be less reliable.

• One strength of using post-mortem examinations is that they can provide detailed information about brain structure. Researchers are able to closely examine areas of the brain that would be difficult to study using scanning techniques alone. This has helped psychologists understand the link between specific brain regions and behaviour, particularly in cases of unusual damage or disorders. Therefore, post-mortem examinations have contributed valuable evidence to our understanding of localisation of function in the brain.