1. Electroencephalogram (EEG), Wakefulness and Sleep

4. The EEG be recorded with Scalp electrodes through the unopened skull or with electrodes on or in the brain. A normal EEG

8. Alpha Block: Replacement of the alpha rhythm by an asynchronous, low-voltage beta rhythm when opening the eyes.

11. SPONTANEOUS CORTICAL ELECTRICAL POTENTIALS: THE EEG

12. Diagrammatic comparison of the electrical responses of the axon and the dendrites of a large cortical neuron. 2. Mechanism of EEG Current flow to and from active synaptic knobs on the dendrites produces wave activity, while AP are transmitted along the axon.

15. EEG Records During Epileptic Seizure Epilepsy is characterized by uncontrolled excessive activity of either a part or all of the central nervous system. Grand mal epilepsy: characterized by extreme neuronal discharges in all areas of the brain, last from a few seconds to 3 to 4 minutes. Petit mal epilepsy: Characterized by 3 to 30 seconds of unconsciousness or diminished consciousness during which the person has several twitch-like contractions of the muscle.

16. II Wakefulness and Sleep

24. Pontine-geniculate-occipital (PGO) wave – A synchronized burst of electrical activity that originates in the pons and like a wave it activates the lateral geniculate nucleus (first relay of visual information) and then the occipital lobe, specifically in the visual cortex (which receives and puts together the visual information that comes from the lat. geniculate nucleus). PGO waves appear seconds before and during REM sleep.