The device of the present invention can automatically extract words under accurately controlled set conditions. A word presenting means presents words to a subject, a biological activity measuring means measures the biological activity in the subject, and a calculation means receives a biological activity signal from the biological activity measuring means and calculates time from presenting the words until detecting a biological activity by the subject accompanied with the word. The calculation means is equipped with a word database where word data indicating words are stored and can be presented to the subject, a category data of the words and attribute data of the words are related and also stored, respectively, and a word extractor to search the word database and to extract the word data belonging to or relating to a predetermined category, and, satisfying predetermined word attribute, based upon the search conditions. The word presenting means presents a portion of or entire words indicated by the word data extracted by the word presenting means to the subject.