Deep Brain EEG Measurement The cortex is the “bark” on the outside of the brain–about a quarter-inch thick. There is no “deep-brain cortical structure.” There are a number of structures in the mid-brain which are heavily involved in how the brain works, but there’s a problem. EEG is produced by one (of many) type of neuron called pyramidal. The cortex has a high concentration of pyramidal neurons, and it is on the surface of the brain, so we can record […]