Psychophysiological measures

Question 1

Electromyography (EMG)

Answer 1

• measures muscle tension
• recorded from two electrodes on surface of skin
• used in sleep research
• measures motor responses
• somatic nervous system

Question 2

EEG

Answer 2

• measures gross electrical activity
• electrodes placed on scalp
• wave forms associated with specific stages on consciousness eg alpha and beta waves

Question 3

Electrooculography (EOG)

Answer 3

• measures eye movements
• based on potential difference between front and back of eyeball
• somatic nervous system

Question 4

MEG

Answer 4

• measures magnetic field of electrical activity
• neurofeedback and sleep research
• better spatial resolution
• more expensive
• needs cooling from liquid helium

Question 5

Structural imaging

Answer 5

different types of tissues have different physical properties
skull grey matter, white matter, etc
can be used to construct maps of physical structures
most common CT and MRI

Question 6

Computed tomography (CT)

Answer 6

• measures the amount of absorption of x-rays (bones absorb most, CSF = least)
• 8-9 x-ray photographs taken
• used to diagnose tumours
• computer algorithm constructs 3D image
  radiation is bad

Question 7

Magnetic resonance imaging (MRI)

Answer 7

• high resolution structural images
• measures radio frequency of waves emitted from hydrogen atoms in a strong magnetic field
• no radiation

Question 8

Positron emission tomography (PET)

Answer 8

• provides functional images
• uses radioactive tracers injected into the blood stream
• widely replaced by fMRI