Ways of studying the brain

Purpose of scanning in psychological research

Is often to investigate localisation- to determine which parts of the brain do what

Functional magnetic resonance imaging (fMRI)

fMRI works by detecting the changes in both blood oxygenation and flow that occur as a result of neural activity in specific parts of the brain

When a brain area is more active it consumes more oxygen and to meet this increased demand, blood flow is directed to the active area

fMRI produced 3D images showing which parts of the brain are involved in a particular mental process and this has important implications for our understanding of localisation of function

Electroencephalogram (EEG)

EEG measures electrical activity within the brain via electrodes that are fixed to an individuals scalp using a skull cap

Sensors placed on the person’s scalp record the brainwave patterns that are generated from the action of thousands of neurons, providing an overall account of brain activity

EEG is often used by clinicians as a diagnostic tool to detect unusual arrhythmic patterns of brain activity which may indicate neurological conditions such as epilepsy, tumours or some sleep disorders

Event related potentials

Although EEG has many scientific and clinical applications, in its raw form it is a crude and overly general measure of brain activity

However, within EEG data are contained all the neural responses associated with specific sensory, cognitive and motor events that may be of interest to cognitive neuroscientists

As such, researchers have developed a way of teasing out and isolating these responses

Using a statistical averaging technique, all extraneous brain activity from the EEG is filtered out leaving only those responses that relate to say, the presentation of a specific stimulus or performance of a specific task

What remains are event related potentials - types of brainwave that are caused by particular events

Research has revealed many different forms of ERP and how, for example, these are linked to cognitive processes such as attention and perception

Post mortem examinations

This is a technique involving the analysis of a persons body including the brain following their death

In psychological research, individuals whos brains are subject to a post mortem examination are likely to be those who have a rare condition and have experienced unusual dysfunctions in cognitive processes or behaviour during their lifetime

Areas of damage within the brain are examined after death as a means of establishing the likely cause of the condition the person experienced

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