Complex sentence: An EEG typically includes 19 channels of EEG electrodes placed on the scalp, whereas a dense-array EEG can include up to 256 channels of EEG electrodes for improved spatial resolution.
Split into simpler sentences: An EEG typically includes 19 channels of EEG electrodes placed on the scalp. A dense-array EEG can include up to 256 channels of EEG electrodes for improved spatial resolution.