This useful information presentation device (300, 301, 302) is provided with: a facial skin temperature acquisition means (20) and/or an image data acquisition means (120); a brain activity estimation means (30, 130); and a useful information presentation means (200). The facial skin temperature acquisition means (20) acquires facial skin temperature data in a time series. The image data acquisition means (120) acquires captured images of the face in a time series. The brain activity estimation means (30, 130) estimates the brain activity of a subject on the basis of a plurality of components obtained by decomposing the facial skin temperature data and/or facial blood flow data by singular value decomposition, principal component analysis, or independent component analysis. The useful information presentation means (200) presents useful information relating to an emotional or physical state on the basis of the brain activity of the subject estimated by the brain activity estimation means (30, 130).
USEFUL INFORMATION PRESENTATION DEVICE