Neuroimaging Techniques

• Functional neuroimaging allows us to study the brain as it is working 
• It shows which parts of the brain are working when doing certain mental tasks 

Functional Magnetic Resonance Imaging (fMRI)

• Detects and records brain activity by measuring oxygen consumption across the brain 
• There is no need for radioactive tracers
• More oxygen will be present in areas of the brain that have more blood flow (which has greater concentrations of oxygen)

Positron Emission Tomography (PET) 

• Produces coloured images showing brain structure, activity and function
• Some tasks that PET imaging is used for to show the brain activity/function include
  • Imagining
  • Talking
  • Remembering
  • Listening
  • Reading
• The images are produced by injecting a radioactive tracer into the bloodstream
• Where brain regions are active, there is an increase in blood flow, which shows up on the image
  • Dark red when there is a lot of brain activity present 
  • Blue when there isn't much brain activity 

Computerised Tomography (CT) or Computerised Axial Tomography (CAT) 

• CT scans use x-ray technology to scan the brain at different angles
• Patients are injected with a substance 'contrast' which is used to highlight the brain's blood vessels in order to interpret the images 
• Used mostly for seein the shapes and images of the brain 
• Is useful for revealing abnormalities in the brain structure of mental illness sufferers (such as parkinson's disease or schizophrenia)
• However CT scans use x-ray technology which is good at showing brain structure but not so good at showing brain tissue

Magnetic Resonance Imaging (MRI)

• Uses magnetic fields to vibrate atoms in the brain's neurons to generate a computer image of the brain
• More detailed and sensitive than CT scans and can be produced in full colour
• Can display small changes in the brain's anatomy and can distinguish between cancerous and non-cancerous issue