Clinical EEG RhythmsClinical EEG Rhythms

Eyes Closed BaselineEyes Closed Baseline

Eyes Open BaselineEyes Open Baseline

Spectral Plot is one way to present frequency and Spectral Plot is one way to present frequency and amplitude information – start hereamplitude information – start here

Brain MapsBrain Maps

TopometricsTopometrics

Frontal Slowing during Math: Frontal Slowing during Math: AbnormalAbnormal

Numbers for Statistical AnalysisNumbers for Statistical Analysis

Quantitative EEG (QEEG) Quantitative EEG (QEEG)

Some of the signal properties that Some of the signal properties that can be quantifiedcan be quantified

Also between-site differences…Also between-site differences…

Absolute Absolute MagnitudeMagnitude

Relative Relative MagnitudeMagnitude

AsymmetryAsymmetry

CoherenceCoherence

Attenuation of temporal lobesAttenuation of temporal lobes Beta1=SMRBeta1=SMR Waveform morphologyWaveform morphology BipolarBipolar Non-specific arousalNon-specific arousal

Role of Topography and “Timing”Role of Topography and “Timing”

Waveform morphologyWaveform morphology

Power vs MagnitudePower vs Magnitude Squared microvolts vs microvoltsSquared microvolts vs microvolts

Cross-spectral analysisCross-spectral analysis

Coherence estimates phase consistency Comodulation estimates magnitude consistency …between signals at each specified frequency

Coh = average normalized cross-spectrum amplitude2

Comod = average normalized cross-product amplitude

Coh range from 0.0 to 1.0 Comod range from -1.0 to 1.0

Confusing point: Tukey called “coherency” the square root of coherence

Signals are Signals are coherentcoherent when when phase relationship phase relationship is stableis stable Signals are Signals are

comodulated comodulated (or (or hypermodulated) hypermodulated) when magnitude when magnitude relationship is relationship is stablestable

ComodulationComodulation

Each site compared to all others (& itself) Each site compared to all others (& itself) in each headin each head

An individual’s data (rho) and An individual’s data (rho) and his/her statistical (z) comparison his/her statistical (z) comparison

to the databaseto the database

MTBI patient Rage DisorderMTBI patient Rage Disorder

HypermodulationHypermodulation

HypomodulationHypomodulation

Current EEG ApplicationsCurrent EEG Applications

CLINICALCLINICAL Epilepsy (1930s)Epilepsy (1930s) Sleep (1940s)Sleep (1940s) Patient monitoring, anaesthesiaPatient monitoring, anaesthesia Head injury assessmentHead injury assessment Neurological assessment (AEP, Neurological assessment (AEP, ERPERP)) NeurotherapyNeurotherapy Psychiatric assessmentPsychiatric assessment

Current EEG ApplicationsCurrent EEG Applications

SCIENTIFICSCIENTIFIC AttentionAttention WorkloadWorkload Circadian rhythmsCircadian rhythms CognitionCognition Learning & MemoryLearning & Memory Neuroimaging co-registrationNeuroimaging co-registration

Future EEG AssessmentFuture EEG Assessment

Subtype clinical conditionsSubtype clinical conditions Monitor attentional stateMonitor attentional state Lie DetectionLie Detection Parole dispositionParole disposition