Brain Scans

Question 1

Describe how brain scans have been used in psychology (6)

Answer 1

There’s three types of that have been recently developed: CAT, MRI AND PET scans.
- CAT scans involving taking a series of x rays and combining them to make a dimensional picture of the area being scanned.
- dye is injected into the patient then they’re placed into a CAT machine to take pictures of the brain structure. In reference to psychology, Johnstone et al used CAT scans to show that schizophrenics brains were different to non schizophrenic brains - the ventricle in the brain were much larger.
- PET scans in lobes administrating radioactive glucose to the patient in which the most active areas of the brain use up glucose.
- PET scans provide images of brain activity rather than brain structure
- in reference to psychology, Raine et al used PET scans to compare brain activity in murderers and normal individuals.
- the found differences in the regions (like the prefrontal cortex) previously linked with aggressive behaviour

Question 2

Discuss the strengths and weaknesses of brain scans

Answer 2

• one strength of pet scans is that they reveal chemical information that isn’t available with other imaging techniques. So we can distinguish between benign and malignant tumors. For example, pet scans can also show the brain in action, which is useful for psychological research.
• however one weakness of PET scans is that it’s expensive so isn’t easily available for research. It’s also less precise than MRI scans.
• one strength of CAT scans is the its useful for revealing abnormal structures in the brain like tumours because the quality of images is much high than that of traditional x- rays.
• one weakness of CAT scans is that they require more radiation than traditional x-rays and the more detailed the the CAT scan is the more radiation exposure the patient receives.