Electrocorticography

Electrocorticography (ECoG) is the practice of using an electrode placed directly on the brain to record electrical activity directly from the cerebral cortex. By placing the electrode directly onto the cortical grey matter one can record signals from neurons much more effectively than through electroencephalography (EEG). One of the main limitations of EEG is the poor spatial resolution, because the skull acts as an attenuator of neural signal, thus filtering out high frequency signals and lowering the signal-to-noise ratio. ECoG electrodes provide higher spatial and temporal resolution than EEG, but worse resolution than single unit recordings. ECoG is typically subdural, although placing electrodes epidurally may have promise in BCI use, as it doesn't break the Blood-brain barrier.