Are present during mental thought and activity History Richard Caton (1875) –localization of sensory functions with monkeys and rabbits Hans Berger (1924) – first EEG recording done on humans - described alpha wave rhythm and its suppression compared to beta waves - acknowledged “alpha blockade” when subject opens eyes William Grey Walter – influenced by Pavlov and Berger, further developed EEG to discover delta waves during sleep (1937) and theta waves (1953) Īlpha Wave Characteristics: - frequency: 8-13 Hz -amplitude: 20-60 µV Easily produced when quietly sitting in relaxed position with eyes closed (few people have trouble producing alpha waves) Alpha blockade occurs with mental activity -exceptions found by Shaw(1996) in the case of mental arithmetic, archery, and golf putting īeta Waves Characteristics: -frequency: 14-30 Hz -amplitude: 2-20 µV The most common form of brain waves. Sodium-Potassium Pump The mechanism within neurons that creates action potentials through the exchange between sodium and potassium ions in and out of the cell Adenosine Triphosphate (ATP) provides energy for proteins to pump 300 sodium ions per second out of the cell while simultaneously pumping 200 potassium ions per second into the cell (concentration gradient) Thus making the outside of the cell more positively charged and the neuron negatively charged This rapid ionic movement causes the release of action potentials
#EASY EEG INTERPRETATION EMOTION SKIN#
Measured amplitudes are lessened with electrodes on surface of skin compared to electrocorticogram Function of EEG The EEG uses highly conductive silver electrodes coated with silver-chloride and gold cup electrodes to obtain accurate measures… use impedance device to measure effectiveness, resistance caused by dura mater, cerebrospinal fluid, and skull bone Monopolar Technique : the use of one active recording electrode placed on area of interest, a reference electrode in an inactive area, and a ground Bipolar Technique : the use of two active electrodes on areas of interest Measures brain waves (graphs voltage over time) through electrodes by using the summation of many action potentials sent by neurons in brain.