PSYCH 160A Lecture Notes - Lecture 5: Local Field Potential, Electrocorticography, Electroencephalography
25 Jan 2020
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Document Summary
Unit recordings in humans initiated for medical purposes only. Seizures may be induced by aberrant neural activity in a focal region relieve symptoms by resecting that region. Local, critical function (e. g. inducing interference in speech) Most research-based recordings in humans use surface electrodes. Reveals the synaptic activity of local neural populations (many neurons) Must pre-select brain areas within which to measure. Difficult to determine interactions between neurons, particularly long- range connections. Selection bias: typically only report on neurons with vigorous responses. Electroencephalography (eeg) measures electrical activity that is readable from the scalp. Measures populations of neurons with synchronized synaptic activity & oriented similarly. Activity from a single neuron is too small to be picked up. Also catches the electrical activity of the muscles in the head. Part of the noise in the measurements removed with statistical techniques. An effective resolution of ~50msec (1/20th of a second) Requires large populations of neurons to be synchronized.
