A load of a stimulating task on an examinee with a resting task being unstable is excluded, and an accurate answer of an examinee to presentation of a stimulating task is enabled. A stimulating task presentation device in a living body optical measurement device includes a stimulation presenting unit configured to present a stimulation to an examinee, a brain function measurement device for measuring a brain function of the examinee in parallel to presentation of the stimulation, and a stimulation presentation controller configured to control the stimulation presented by the stimulation presenting unit, and the stimulation presentation controller has a function of setting a resting task and a stimulating task to be presented to the examinee, a function of detecting an answer of the examinee to the resting task and the stimulating task, and a task presentation control function of determining the degree of stability on the basis of the detection result when the resting task is presented, and controlling presentation of the resting task or the stimulating task on the basis of the degree of stability.
