5A - Understanding the Brain

Question 1

What is Phrenology?

Answer 1

observing or feeling the skull to determine someone’s psychological characteristis and traits.

Question 2

Why has Phrenology been discredited?

Answer 2

Because there was growing evidence against Phrenology and there never was any scientific research behind it. It was a pseudoscience.

Question 3

What are the 4 neuroimaging techniques? (full titles)

Answer 3

CT - Computerised Tomography
MRI – Magnetic resonance imaging
PET – Positron emission tomography
fMRI – functional magnetic resonance imaging

Question 4

CT Scan - full name, information provided, how it works, what it’s used for.

Answer 4

Provides information on structure only.

Combines a series of x-rays taken at different angles to create a black and white 2D image of a cross section of the brain.

Patient must be injected with an iodine-based substance (contrast) that makes certain brain structures more visible.

Used to assess the damage caused by strokes, injuries, tumours and disease.

Question 5

MRI - full name, information provided, how it works, compare to CT scan.

Answer 5

Provides information on structure only.

Produces a more detailed image than a CT and does not require harmful x-rays

A person’s head is placed in a chamber and a magnetic field is created around it; radio waves are pulsed to vibrate brain neurons. The vibrations are detected and used to produce the image.

Question 6

PET - full name, information provided, how it works.

Answer 6

Positron Emisson Tomography

Provides information on structure and function.

Patients have radioactive glucose injected into bloodstream and electrodes placed around their head to detect positrons emitted by the radioactive glucose (harmless)

Patients are asked to engage in a specific task, the amount of glucose used by each area of the brain is recorded.

Question 7

fMRI- full name, information provided, how it works, compare to MRI, Advantages.

Answer 7

Provides information structure and function.

Works like a standard MRI while also making brain activity visible on a computer screen

fMRI detects the differences between oxygenated and deoxygenated blood in the brain as it undertakes different tasks, with the assumption that active brain structures will require more oxygen.

Advantages: No radioactive substances required, more detailed and accurate than PET scans.