CGSC 2002 Lecture 11: Neuroscience 1
19 Mar 2018
School
Department
Course
Professor
Document Summary
The resulting brain record is referred to as an electroencephalogram (eeg). Because electromagnetic waves propagate instantaneously, eeg is temporally sensitive. Eeg is more sensitive to neurons near the surface than to deeper neurons. Eeg does not provide good spatial resolution for localization of cognitive functions. Electrical fields are recorded through a grid of electrodes applied to the skull. Can be placed anywhere on the scalp. Is related to the way eeg amplifiers are designed. Is used to reduce noise from the amplifier ground circuit. A1 and a2, on the image, are reference electrodes. Reference electrodes are commonly placed on mastoid bone behind the ears. In reality, given how neural activity is conducted, the voltage recorded between an active site and a reference site will reflect neural activity at both of the sites. Raw eeg is a combination of many different kinds of activity in the brain. Some of this activity reflects transient brain responses to specific stimuli (event-related potentials (erps)
