An electrode for detecting EEG signals comprises a body comprising a fixture on a first end of the body, and a sensor detachably held by the fixture, wherein the body has an external thread in a portion of the body extending from the first end of the body towards a second end of the body, and the sensor has a brush-like shape with pins protruding off the body. The electrode may be held by an attaching device for holding electrodes for detecting EEG signals, the attaching device comprising a strap including a plurality of holes for accommodating electrodes and a rotary closure connecting a first end of the strap and a second end of the strap.
