0.8 Ways of studying the brain

what are the 4 methods of studying the brain

• FMRI

• Post-Mortem

• EEG

• ERP

what is fMRI

Functional Magnetic Resonance Imaging

uses a magnetic field and radio waves to detect changes in blood oxygenation and flow as a result of neural activity to create a moving picture of the brain

strengths of fMRI

good spatial resolution - can track location

allows us to research the active brain

limitations of fMRI 

low temporal resolution - can’t track changes 

complex and can be affected by the baseline task used and how the data is interpreted 

what study supports fMRI

phelps et al

used fMRI to examine the role of the amygdala in emotional memory.

found increased activity in the amygdala when participants recalled emotionally charged memories.

fMRIs ability to localise brain activity linked to specific cognitive functions

what is EEG

Electroencephologram

use electrodes fixed to a participants scalp which detect neuronal activity directly below where they are placed 

strengths of EEG

cheaper than fMRIs so enables larger sample sizes which can increase the validity of data gathered

better temporal resolution - active changes

allow the active brain to be investigated during specific tasks

limitations of EEG

poorer spatial resolution than fMRIs

study supporting EEGs

Dement and Kleitman

• used EEG to investigate the relationship between REM sleep and dreaming

• found that REM sleep was strongly associated with dreaming as shown by brain wave patterns

• supports EEG’s usefulness in studying sleep and brain states over time

what is ERP 

Event Related Potentials

uses electrodes fixed to a participants scalp to detect neuronal activity in response to a stimulus introduced by the researcher 

strengths of ERP

cheaper than fMRIs

allow the active brain to be investigated during specific tasks

limitations of ERP

poorer spatial resolution than fMRIs

study support for ERP

Luck et al

• used ERPs to study attention and visual processing

• identified specific ERP components linked to attention and decision making

  • shows ERPs can isolate cognitive processes with high temporal precision

what is the Post-Mortem method 

studying the brain after death to try and correlate structural abnormalities to behavioural changes 

strengths of post-mortem method

enables deeper region of the brain to be investigated than non-invasive techniques

limitations of using Post-Mortem method

requires special permission to be conducted

can be effected by changes which occur during/after death

can’t actively study

study supporting Post-Mortem methods

Broca - Tan 

• studied the brain of a patient (Tan) who had lost speech ability 

• found damage to a specific area in the left frontal lobe - now called the Broca’s area

• Post-mortem studies can link brain structure to function, especially in language 

• looked at the brain again and it had changed area - wider than at first thought