How many inputs does each channel of the EEG instrument have?

Each channel of the EEG instrument typically consists of two inputs, which allows for differential recording. The two inputs are utilized to measure the electrical activity between two distinct points on the scalp. This differential recording is crucial as it helps to enhance the signal related to brain activity while minimizing noise and interference from other sources, such as muscle activity or electromagnetic interference.

Additionally, each channel includes a ground or common reference point, which serves as a stable baseline for the measurements. This setup is essential for obtaining accurate and reliable readings of the brain's electrical activity. Therefore, the configuration of two inputs and a ground/common is the standard for EEG channels. This design is fundamental for capturing the complexities of brain signals accurately and is widely used in EEG practice.