Pattern of EEGIrregular·Amplitude①the degree of synchronous firing of2whichever neurons generating the synaptic?④activityS0.5~100μV(1000timessmallertheAP)6Sum=EEGsynchronicity,activity(b)·FrequencySynchronizedhow often the wave cycles from maxD?amplitude to mini amplitude and back?1~ >40Hz?responsive states?6Sum=EEG(c)
Pattern of EEG •Amplitude the degree of synchronous firing of whichever neurons generating the synaptic activity 0.5~100μV (1000 times smaller the AP) synchronicity, activity • Frequency how often the wave cycles from max amplitude to mini amplitude and back 1~ >40Hz responsive states
PatternofEEG.The synchronicity of the corticalsynaptic activity (amplitudeof EEG)is a reflection of the degree ofCortexsynchronous firing of the thalamicneuronal clusters generating EEG·OscillationOutputidling hypothesispathwaysepiphenomenonhypothesisThalamusAfferentDathwavs
Pattern of EEG • The synchronicity of the cortical synaptic activity (amplitude of EEG) is a reflection of the degree of synchronous firing of the thalamic neuronal clusters generating EEG •Oscillation idling hypothesis epiphenomenon hypothesis
EpilepsyNormal EEGParietal lobeAcommon neurologicaldiseaseOccipitallobe(mild, intermediate, severe)FrontallobeTemporal lobeAbnormal synchronized discharges ofCerebellumcerebral neuronsLesssynchronizedGeneralizedseizureEEGRecurrent waves havingdistinctivehigh amplitudes (up to 1000μV) andindividual spikes or the combinationStereotyped changes in behavior(seizures,lossofconsciousnessetc.)AntagonistofGABAreceptor→promoteHighlysynchronizedAlcohol,tranquillizerinhibitwebdicine.com
Epilepsy • A common neurological disease (mild, intermediate, severe) • Abnormal synchronized discharges of cerebral neurons • Recurrent waves having distinctive high amplitudes (up to 1000μV) and individual spikes or the combination • Stereotyped changes in behavior (seizures, loss of consciousness etc.) webdicine.com Less synchronized Highly synchronized Antagonist of GABA receptor → promote Alcohol, tranquillizer → inhibit
The Waking StateBeta(β)wwwn13-30HzEEGarousalwwwwwwwwwwmAlpha(a)8-13Hzelements.spiritalchemy.comAlpharhythmslowoscillationanawake,relaxedadultwhoseeyes arecloseddecreased level of attentionBeta rhythm lower amplitude, higher frequency oscillationattentive to an external stimulus or thinking hard about somethingtheact of payingattentiontoastimulusRepeated stimuli → back to alpha thythm
The Waking State • Alpha rhythm slow oscillation an awake, relaxed adult whose eyes are closed decreased level of attention • Beta rhythm lower amplitude, higher frequency oscillation attentive to an external stimulus or thinking hard about something the act of paying attention to a stimulus Repeated stimuli → back to alpha thythm EEG arousal elements.spiritalchemy.com
SleepS.Thetarhythm and delta rhythmSlower-frequency,higher-amplitudelibrary.thinkquest.orgBeta(β)yy13-30HzAwakewwwwwwwwwwmAlpha(α)8-13HzTheta (0)M4-8HZSleepDelta (8)0.5-4Hzelements.spiritalchemy.comh
Sleep Sleep Awake elements.spiritalchemy.comh • Theta rhythm and delta rhythm Slower-frequency, higher-amplitude library.thinkquest.org