Brain scans

• Brain scans are a technique used to investigate the functions of the brain by taking either 2D or 3D images of the living brain
• Computed Axial Tomography (CAT); A series of x-rays, combined they create 2 or 3 dimensional pictures (Weign Berger et al; Larger ventricle sizes which schizophrenia than normal group)

  +Good for identifying structural abnormalities in the brain e.g. tissue damage

  +Better quality than traditional x-rays

  -Expose ppt to more radiation than traditional x-rays (cannot use on pregnant women)

  -Images less detailed than MRI and cannot show the brain in action like PET
• Magnetic Resonance Imaging (MRI); Magnetic field changes hydrogen atom alignment in the brain, produces 2 or 3 dimensonial images (Maguire et al; Used London taxi drivers had larger hippocampus than control)

  +Produces a more detailed image of soft tissue that CAT and PET

  +Does not use x-rays, less risk of harm than CAT, can be used several times in short period on same ppt

  -They can take a long time and can be uncomfortable for ppt

  -Cannot show the brain in action like PET scan can
• Positron Emission Tomography (PET); Administer slightly radioactive glucose traces, most attrive part of brain uses the tracers, radiation detectors 'see' the tracers and produce both still and moving images (Raine et al; Difference in NGRI V control)

  +Can show the brain in action whilst ppts perform tasks

  -More expensive which causes it to be less accessible

  -Less precise than MRI
• Overall strengths

  +Provides detailed and objective measure of neural activity, little room for bias making it reliable

  +Investigate neural activity in action with ppt like Raine did

  Overall weaknesses

  -Scanning machines can be expensive, therefore less accessible

  -Scans like PET can be long and uncomfortable, may reduce the number of those willing to partake

  -Limited range of activities can be investigated due to machine limitations