Phases of Memory
One of the first things apt to be noticed by the student of memory is the fact that there are several different phases of the manifestation of memory. That is to say, that there are several general classes into which the phenomena of memory may be grouped. And accordingly we find some persons quite highly developed in certain phases of memory, and quite deficient in others. If there were but one phase or class of memory, then a person who had developed his memory along any particular line would have at the same time developed it equally along all the other lines. But this is far from being the true state of affairs. We find men who are quite proficient in recalling the impression of faces, while they find it very difficult to recall the names of the persons whose faces they remember. Others can remember faces, and not names. Others have an excellent recollection of localities, while others are constantly losing themselves. Others remember dates, prices, numbers, and figures generally, while deficient in other forms of recollection. Others remember tales, incidents, anecdotes etc., while forgetting other things. And so on, each person being apt to possess a memory good in some phases, while deficient in others.
The phases of memory may be divided into two general classes, namely (1) Memory of Sense Impressions; and (2) Memory of Ideas. This classification is somewhat arbitrary, for the reason that sense impressions develop into ideas, and ideas are composed to a considerable extent of sense impressions, but in a general way the classification serves its purpose, which is the grouping together of certain phases of the phenomena of memory.
Memory of Sense Impressions of course includes the impressions received from all of the five senses: sight; hearing; taste; touch; and smell. But when we come down to a practical examination of sense impressions retained in the memory, we find that the majority of such impressions are those obtained through the two respective senses of sight and hearing. The impressions received from the sense of taste, touch and smell, respectively, are comparatively small, except in the cases of certain experts in special lines, whose occupation consists in acquiring a very delicate sense of taste, smell or touch, and correspondingly a fine sense of memory along these particular lines. For instance, the wine-taster and tea-tasters, who are able to distinguish between the various grades of merchandise handled by them, have developed not only very fine senses of taste and smell, but also a remarkable memory of the impressions previously received, the power of discrimination depending as much upon the memory as upon the special sense. In the same way the skilled surgeon as well as the skilled mechanic acquires a fine sense of touch and a correspondingly highly developed memory of touch impressions.
But, as we have said, the greater part of the sense impressions stored away in our memories are those previously received through the senses of sight and hearing, respectively. The majority of sense impressions, stored away in the memory, have been received more or less involuntarily, that is with the application of but a slight degree of attention. They are more or less indistinct and hazy, and are recalled with difficulty, the remembrance of them generally coming about without conscious effort, according to the law of association. That is, they come principally when we are thinking about something else upon which we have given thought and attention, and with which they have been associated. There is quite a difference between the remembrance of sense impressions received in this way, and those which we record by the bestowal of attention, interest and concentration.
The sense impressions of sight are by far the most numerous in our subconscious storehouse. We are constantly exercising our sense of sight, and receiving thousands of different sight impressions every hour. But the majority of these impressions are but faintly recorded upon the memory, because we give to them but little attention or interest. But it is astonishing, at times, when we find that when we recall some important event or incident we also recall many faint sight impressions of which we did not dream we had any record. To realize the important part played by sight impressions in the phenomena of memory, recall some particular time or event in your life, and see how many more things that you _saw_ are remembered, compared with the number of things that you _heard_, or tasted, or felt or smelled.