Ways of studying the brain: AO1 + AO3

What are the 4 ways of studying the brain?

• post-mortem analysis

• functional magnetic resonance imaging (fMRI)

• electroencephalogram (EEG)

• event related potential (ERP)

How does post-mortem analysis work?

It involves studying the individuals behaviour while they’re alive

-It may also use secondary sources to collect data on abnormal behavior tendencies of the person after death (from friends/relatives)

-researchers will then examine a person’s brain after their death and compare it to a neurotypical brain to identify damaged or abnormal areas

Such areas are then correlated with the abnormal behaviours observed during a person’s life

How does fMRI work?

It uses magnetic fields and radio waves to detect changes in blood flow and blood oxygenation caused by neural activity

-this is done by measuring the change in energy released by an increase in oxygenated haemoglobin

-this is used to work out which areas of the brain are consuming more oxygen (and infers these must be the areas which are the most active)

-during fMRI scan, ppts complete a baseline and an experimental task, while their brain activity is being measured

-areas with high blood flow/oxygen consumption in the experimental task that the baseline task (and thus more activity) appear a red/yellow on a 3D activation map and a moving image that the scan generates

extra info about fMRI: biology aspects

1) iron is needed to form haemoglobin, the magnetic waves detect iron and this is what tells you when oxygen is being used, and oxygen itself binds to haemoglobin

2) where oxygen is being used is where the activity is (haemoglobin carries oxygen)

3) more energy is needed for respiration

How does EEG work?

it works by placing electrodes on the scalp and it measures the brain’s activity and detects small electrical charges caused by the brain cell activity directly under the area of placement (action potentials)

-number of electrodes depends on the specific area of the brain being studied, the wider the area, the more electrodes need to be placed

-EEG’s measure overall activity of the brain linked to different states (e.g. abnormal states like seizures/epilepsy, wakefulness, drowsiness, REM sleep, deep sleep)

The activity is represented as 5 basic patterns (alpha, beta, delta, theta and gamma waves)

How does the ERP work?

It works by placing electrodes on the scalp and it measures the brain’s activity and detects small electrical charges caused by the brain cell activity directly under the area of placement (action potentials)

-Ppts are repeatedly exposed to a stimulus while their brain activity is recorded

-Statistical averaging techniques are then used and filter out extraneous activity caused by events that are not the stimulus

-Helps identity activity directly triggered by a stimulus and specific electrical activity is identified as the ERP

Post-mortem analysis: Strengths (AO3)

1)Detailed examinations of anatomical and neurochemical features of the brain compared to neuroimaging techniques such as fMRI scans

It can physically assess the brain(unlike the fMRI) that can only visualise them as a diagram. Therefore, precise info can be gathered about brain regions and the neurochemicals involved in particular functions

2)Helped add scientific credibility to the study of the relationship between the brain and behaviours/cognitions and allowed for hypothesis testing using empirical data

The evidence was crucial in building the first understanding of key brain processes. E.g. Paul Broca used PMA to establish the link between language and the brain by showing that an area of the frontal lobe is related to language production decades before neuroimaging techniques were possible