Electroencephalogram interface system

An eyeglass-type electroencephalogram interface system having an endpiece portion, a rim portion, and a nose pad portion, and to be worn on a head of a user, comprising:

• an output section, disposed at the rim portion, and configured to present a visual stimulation to the user;
• an ear electrode portion disposed at a position coming in contact with an ear of the user when the eyeglass-type electroencephalogram interface system is worn;
• a facial electrode portion disposed at the nose pad portion coming in contact with a face of the user below a straight line connecting an external canthus and an internal canthus of an eye of the user, such that the mass of the eyeglass-type electroencephalogram interface system is supported at the nose pad portion, when the eyeglass-type electroencephalogram interface system is worn;
• an electroencephalogram measurement and determination section configured to measure an event-related potential on the basis of a potential difference between the ear electrode portion and the facial electrode portion, based on a timing of presenting the visual stimulation as a starting point;
• and
• a facial electrode position determination section configured to determine a position of the facial electrode portion based on whether, in the electroencephalogram signal of the user, an amplitude of a signal associated with a blink of the user falls between a predetermined upper threshold value and a predetermined lower threshold value;
• wherein the facial electrode position determination section determines that the position of the facial electrode portion has shifted in a lower direction if the amplitude of the signal is greater than the upper threshold value, and that the position of the facial electrode portion has shifted in an upper direction if the amplitude of the signal is equal to or less than the lower threshold value.