ways of studying the brain

How does an EEG work

• Electrodes are placed onto scalp detecting neural activity directly below where they are placed - number of electrodes used my vary depending on focus of research

Strengths of EEGs

• significant in understanding sleep patterns- helped researchers determine the 5 stages of sleep

Limmitation of EEGs

• EEG can only detect surface activity within accessible regions of the brain

  • This is a limitation as EEGs cannot provide insight as to what is happening in deeper regions of the brain

  • Therefore EEG is limited as to what it can achieve in terms of measuring brain activity

What are ERPs

1. Electrodes are placed onto scalp scalp to measure neural activity directly below directly below where they are placed

2. In response to a stimuli introduced by researcher

Strengths of ERPs

• high temporal resolution

Limitations of ERPs

Poor spatial resolution

Outline the difference between EEGs and ERPs

• Type of data

  • EEG: Continuous, general brain activity

  • ERP: Specific response to a stimulus (time-locked)

• Specificity

  • EEG: Low specificity (hard to tell exactly what caused activity)

  • ERP: Higher specificity (linked to a particular event or process)

Describe FMRI

• FMRI measures oxygenated blood flow in the brain i.e. brain activity 

• Oxygenated blood has a different resonance than deoxygenated blood

  • More active areas of the brain receive more oxygenated blood

• fMRI uses magnets to detect changes in blood flow
  

What are some strengths of fMRI

• high spatial resolution

• Shows both activity and structure of the brain

• Non-invasive procedure - highly ethical

Weaknesses of fmri

• low temporal resolution - 5 second delay between brain activity and measurement

• This means som important activity may not be detected

• fMRI are highly expensive - economic implications - limited practicality

What are post mortem exams

An invasive procedure whereby the brain is examined after death to try and correlate structural abnormalities/damage to behaviour

Limitations of post mortem exams

• Shared structural abnormalities in neurodivergent brains may be a result of same medication use as opposed to it being the direct cause

• Ethical issues - ability to obtain full consent may be compromised be patients condition