MRI Brain Scan (HL IB Psychology)

Techniques used to Study the Brain: MRI

What is MRI scanning?

• Magnetic Resonance Imaging (MRI) uses a large magnet and pulses of radio waves to scan the brain, producing images of brain structures

• MRI produces a picture of the inside of the brain or body by measuring hydrogen nuclei in the area that is being scanned

• The patient being scanned is placed inside a ‘doughnut’-type tube and they are asked to keep very still as any movement may affect the precision of the measurement

• The scanner makes a loud, banging noise while it is scanning which may be distressing for the patient

• Patients are asked to remove all metal objects from their person so MRI scanning would not be suitable for anyone with metal implants in their body

• MRI scans can show areas the size of brain structures, the volume of grey matter within those structures, brain damage, bleeding and tumours

Which studies use MRI?

• MRI was used to scan the brains of taxi drivers (Maguire 2000) in order to determine a correlation between spatial navigation and hippocampal grey matter

• Luby et al. (2013) used MRI to assess the affects of poverty on a child’s developing brain

Both of these studies are available as separate Key Studies – just navigate the Brain and Behaviour section of this topic to find them.

What are the strengths and limitations of MRI?

Strengths:

• MRI enables researchers to pinpoint specific brain structures which may be damaged or have increased grey matter to identify the link between brain and behaviour

• MRI is less invasive than techniques such as PET as it does not require the use of radiation

Limitations:

• MRI scanners are prone to disturbance caused by noise, temperature and human error in calibration which means that they are not always reliable

• MRI scanners would not be suitable for someone who suffers from claustrophobia due to the enclosed environment of the machine