EEG Concepts Flashcards
What creates dipole activity?
Brain cells polarizing to create positive and negative sides?
What are the three characteristics that all dipoles have?
Location, magnitude, orientation
Which cortical layers are the primary generators of scalp potentials?
Cortical layers 2-5
What is an EEG?
A measurement of scalp potentials
What are brainwaves?
A bi-product of pyramidal cells in macro columns resonating with each other
What part of the brain acts as a pace maker for macro columns of pyramidal cells?
Thalamus
The delta rhythm in the brain is generated by what?
Cortical sheet dipoles
The theta rhythm in the brain is generated by what?
The thalamus
The alpha rhythm in the brain is generated by what?
Thalamo-cortical-thalamic interactions.
The beta frequency in the brain is generated by what?
The cortex
The gamma frequency in the brain is generated by what?
Neural networks
What is absolute power a measure of?
The integral of all powers within a given frequency band, expressed as uv squared.
Relative power is a measure of what?
The ratio of absolute power to power in all bands, expressed in percentages
What is amplitude asymmetry?
Difference in amplitude between EEG signals across the cortex
What is coherence?
A measurement of the level of coherence between two different signals in the EEG within the same band (i.e. alpha coherence between the frontal and parietal lobes)
