A short description of the brain scanning method: electroencephalogram. In addition o the basic method, the slideshow also briefly describes the techniques strengths and weaknesses compared to other brain scanning techniques.

1. The EEG
(Electroencephalogram)
{
Jason Konold and Gero Kassing

2. 
One of the older methods of brain scanning

1875, Richard Caton presented findings of
electrical phenomena in the brains of rabbits
and monkeys
1912, Vladimir Vladimirovich PravdichNeminsky created the first animal
electroencephalogram
1924 First human electroencephalogram
recorded by Hans Berger (he also named it)


A Short History

3. Hans Berger

4. { How It Works

5. Large-Scale Neuron Action



Neurons (brain cells) become charged when active
The electrodes are sensors that detect changes in electrical charge
A single neuron becoming charged cannot be detected by an EEG,
so the EEG measures large groups of neurons acting
simultaneously

6. Neurons

7. 


Usually last 20-30 minutes
Electrodes placed on the scalp
 The standard placement is in the “10-20 System” or “International
10-20 System”
Patient conducts activities to generate responses
 Hyperventilating
 Photic stimulation (a fancy way of saying “shine a light in their
face”)
 Sleep (or sleep deprivation)
 Mental exercises
A Typical Clinical Session

8. 10-20 System (of electrode
placement)

9. 


In the 10-20 System, electrodes are given a letter
corresponding to which lobe they are placed on…
 P- Parietal
 T- Temporal
 O- Occipital
 F- Frontal
…or a letter based on general positioning
 Fp- Frontopolar
 C- Central
 A- Auricular (over the ear)
Then they receive a number based on lateral
position: an odd number if on the left hemisphere
and an even number if on the right
Naming the Electrodes

10. For Example
Right hemisphere,
first electrode in
auricular area,
therefore it receives
the name A2

11. Electrocorticography (ECoG)



Electrodes may be inserted into the skull
Also known as subdural or intracranial EEG (SD-EEG or I-EEG)
Sometimes used in the case of patients with epilepsy

12. Advantages &
Disadvantages
{

13. Advantages

EEG costs significantly less

Is much more portable

no exposure to magnetic
fields or x-rays

Is silent – this is important
when studying reactions to audio

No claustrophobia

No needles

15. Disadvantages

Sticky electrodes

Poor resolution

Most sensitive to post-
synaptic potentials – cortex
Large areas of the cortex have to be activated for
the electrodes to register anything on the skull
 Uncountable number of activity of neurons tells us

what parts of the brain are active, but not enough to
make an exact conclusion to the localization

17. References
Alivanit. (1998, November 27). Advantages of EEG in Comparison to High Technology
Brain Imaging Methods. EEG Manual. Retrieved October 31, 2013, from
http://www.aha.ru/~geivanit/EEGmanual/Advantages.htm
Brain neuron forest. (n.d.). Alzheimer's association. Retrieved October 30, 2013, from
http://www.alz.org/braintour/neuron_forest.asp
Electroencephalography. (2013, October 29). Wikipedia. Retrieved October 31, 2013,
from
http://en.wikipedia.org/wiki/Electroencephalography
Law, A., & Halkiopoulos, C. (2010). The biological level of analysis. Psychology:
developed specifically for the IB diploma (pp. 40 - 41). Oxford, U.K.: Pearson
Education.
Lemke, S. (1999, November 1). History. Department of psychiatry and psychotherapy.
Retrieved October 30, 2013, from http://www.psychiatrie.uk-j.de/ Geschichte.html
Mathias, R. (1996, December 1). The basics of brain imaging. NIDA notes. Retrieved
October
30, 2013, from http://archives.drugabuse.gov/NIDA_Notes/
NNVol11N5/Basics.html
Schachter, S. (2006, December 15). How to read an EEG. Epilepsy. Retrieved October
31, 2013,
from http://www.epilepsy.com/epilepsy/eeg_read
Smith, S. (n.d.). EEG in the diagnosis, classification, and management of
patients
with epilepsy. -- Smith 76 (suppl 2): ii2. Retrieved October 31, 2013,
from
http://jnnp.bmj.com/content/76/suppl_2/ii2.full
What is Electroencephalography (EEG). (2013, February 1). Mega Electronics Ltd RSS.
Retrieved October 31, 2013, from http://www.megaemg.com/knowledge/
electroencephalography-eeg/