introduction to EEG

Question 1

what is electroencephalography

Answer 1

EEG is a method of analysing the continuous neural activity of the brain

Question 2

brain activity

Answer 2

recorded as a wavelength at the scalp by placing small metal electrodes onto the head

Question 3

how are EEG signals produced?

Answer 3

by the summation of 10’000’s of post synaptic potentials, signalling activity within that area

Question 4

where is EEG recorded from?

Answer 4

EEG signals are recorded from close to brains surface.

signals from deeper within the brain have more interference, from brain tissue, scalp and skull.

Question 5

what system is used to measure activity

Answer 5

the 10-20 system, with each electrode labelled representing a location

electrodes corresponding letters represent the brain region they cover (e.g. P1 = parietal lobe)

Question 6

one electrode is attached to an electrically inactive site, where and why?

Answer 6

the mastoid bone, behind the ears

to act as a baseline to compare the other recordings to