In order to support the evaluation of mental activity state using multiple kinds of brain activity signals, a mental activity state evaluation support device which supports the evaluation of the mental activity state of the multiple kinds of brain activity signals is an error measurement signal which shows the degree of the factor other than the cardiac activity state which changes a plurality of kinds of brain activity signals, and a plurality of kinds of brain activity signals An error measurement signal is obtained by detecting the estimated value of the corresponding mental activity state and the error calculation information indicating the correspondence between the estimated value and the error calculation signal, and corresponding to the plurality of kinds of brain activity signals from the acquired error measurement signal by referring to the error calculation informationBased on the magnitude of the calculated error, a first kind of brain activity signal output from a plurality of kinds of brain activity signals is selected.複数種類の脳活動信号を用いた心的活動状態の評価、を支援する、心的活動状態評価支援装置は、複数種類の脳活動信号を変化させる該心的活動状態以外の要因の程度を示す誤差計測信号と、複数種類の脳活動信号それぞれに対応する心的活動状態の推定値、の該要因による誤差と、の対応を示す誤差算出情報を保持し、誤差計測信号を取得し、誤差算出情報を参照して、取得した誤差計測信号から、複数種類の脳活動信号それぞれに対応する心的活動状態の推定値の誤差要因による誤差を算出し、算出した誤差それぞれの大きさに基づいて、複数種類の脳活動信号から出力する第1種脳活動信号を選択する。
