4. LAWS UNDERLYING MEMORY
The development of a good memory depends in no small degree on the closeness with which we follow certain well-demonstrated laws.
The Law of Association.—The law of association, as we have already seen, is fundamental. Upon it the whole structure of memory depends. Stating this law in neural terms we may say: Brain areas which are active together at the same time tend to establish associative paths, so that when one of them is again active the other is also brought into activity. Expressing the same truth in mental terms: If two facts or experiences occur together in consciousness, and one of them is later recalled, it tends to cause the other to appear also.
The Law of Repetition.—The law of repetition is but a restatement of the law of habit, and may be formulated as follows: The more frequently a certain cortical activity occurs, the more easily is its repetition brought about. Stating this law in mental terms we may say: The more often a fact is recalled in consciousness the easier and more certain the recall becomes. It is upon the law of repetition that reviews and drills to fix things in the memory are based.
The Law of Recency.—We may state the law of recency in physiological terms as follows: The more recently brain centers have been employed in a certain activity, the more easily are they thrown into the same activity. This, on the mental side, means: The more recently any facts have been present in consciousness the more easily are they recalled. It is in obedience to this law that we want to rehearse a difficult lesson just before the recitation hour, or cram immediately before an examination. The working of this law also explains the tendency of all memories to fade out as the years pass by.
The Law of Vividness.—The law of vividness is of primary importance in memorizing. On the physical side it may be expressed as follows: The higher the tension or the more intense the activity of neural centers the more easily the activity is repeated. The counterpart of this law in mental terms is: The higher the degree of attention or concentration when the fact is registered the more certain it is of recall. Better far one impression of a high degree of vividness than several repetitions with the attention wandering or the brain too fatigued to respond. Not drill alone, but drill with concentration, is necessary to sure memory,—in proof of which witness the futile results on the part of the small boy who "studies his spelling lesson over fifteen times," the while he is at the same time counting his marbles.
