CINEMA 3 Lecture Notes - Lecture 17: Ultradian Rhythm, Actigraphy, Glucocorticoid
Document Summary
Eeg measures the neural activity of the cerebral cortex. Eeg measures wires taped to scalp with conductive paste fixed to standard positions on the head connected to amplifiers and recording devices. Records many simultaneous squiggles that indicate voltage changes between pairs of electrodes. Measures currents that flow during synaptic excitation of the dendrites of many pyramid neurons in the cerebral cortex. It takes thousands of neurons to measure collective activity because signal has to come through tissue and skull. Amplitude depends on how synchronous the activity of groups of neurons is. Repeated excitation of a group of cells show rhythmic waves. Whenever electrical currents flow, a magnetic field is generated. But hard to cancel out all other magnetic noise . Better than eeg for localizing the sources pf neural activity, particularly deep brain sources. Eeg & meg: directly measure activity of neurons fmri & pet: detect changes in metabolism or blood flow.
