We find that it is a unique mental state. It differs from impression in being a period of more active search for facts in the mind accompanied by expression, instead of a concentration upon the external impression. It is also usually accompanied by motor expressions, either talking or writing. Since recall is a unique mental state, you ought to prepare for it by means of a rehearsal. When you are memorizing anything to be recalled, make part of your memorizing a rehearsal of it, if possible, under same conditions as final recall. In memorizing from a book, first make impression, then close the book and practise recall. When memorizing a selection to be given in a public speaking class, intersperse the periods of impression with periods of recall. This is especially necessary in preparation for public speaking, for facing an audience gives rise to a vastly different psychic attitude from that of impression. The sight of an audience may be embarrassing or exciting. Furthermore, unforeseen distractions may arise. Accordingly, create those conditions as nearly as possible in your preparation. Imagine yourself facing the audience. Practise aloud so that you will become accustomed to the sound of your own voice. The importance of the practice of recall as a part of the memory process can hardly be overestimated. One psychologist has advised that in memorizing significant material more than half the time should be spent in practising recall. There still remains a fourth phase of memory--Recognition. Whenever a remembered fact is recalled, it is accompanied by a characteristic feeling which we call the feeling of recognition. It has been described as a feeling of familiarity, a glow of warmth, a sense of ownership, a feeling of intimacy. As you walk down the street of a great city you pass hundreds of faces, all of them strange. Suddenly in the crowd you catch sight of some one you know and are instantly suffused with a glow of feeling that is markedly different from your feeling toward the others. That glow represents the feeling of recognition. It is always present during recall and may be used in great advantage in studying. It derives its virtue for our purpose from the fact that it is a feeling, and at the time of feeling the bodily activities in general are affected. Changes occur in heart beat, breathing; various glandular secretions are affected, the digestive organs respond. In this general quickening of bodily activity we have reason to believe that the nervous system partakes, and things become impressed more readily. Thus the feeling of recognition that accompanies recall is responsible for one of the benefits of reviews. At such a time material once memorized becomes tinged with a feelingful color different from that which accompanied it when new. Review, then, not merely to produce additional impressions, but also to take advantage of the feeling of recognition.