Practice with the pictures on the wall and direct your attention from one detail to another, always changing before the attention wanders, keeping it absolutely under your control.
Attention to be perfect must be directed to one thing at a time. It must be centered and not scattered. Perfect attention is a rifle, not a shotgun. You can best stimulate attention by use of one sense at a time. At the same time see to it that the other senses are relaxed and at rest.
Divided Attention
It is possible to divide the attention but then it can not be of the highest quality. Try the experiment of doing a simple problem in arithmetic and at the same time say a familiar verse, as "Humpty-Dumpty." Again try to write the lines of "Mary had a little lamb," while you say aloud the lines of "Humpty-Dumpty." While you did succeed in doing the first you do not succeed in doing the second. This experiment should be tried by all children to show them the effect of dividing the attention and of how it may be done when necessary, but only to a certain degree. The difficulty of the verse and problem can be accommodated to the age of the child.
The attention may be divided between two objects or acts if they call for the use of two different senses or are different in their order. You can not divide your attention between two acts of the same order, as two arithmetic problems, one mental and the other written, or between two operations of the same sense. You can not listen to two quartets singing at the same time, but you can attend to one and smell some flowers at the same time and do both fairly well. While using one of the senses for fixed attention train the others to relax.
The Degree of Attention
This will depend upon the strength of the stimulus or force which excites it. The sense of sight is the strongest of all the senses and therefore can exert the strongest stimulus, and should be used in all possible cases. In the exercises with the square the changes are all visual and they continue the strongest stimulus.
Another strong stimulus can be induced by the feelings of either pleasure or displeasure. Happy, joyful anticipation or fear, horror, or disgust will arouse the attention.
Familiarity also aids the attention because of the feelings which it incites. Visual pictures which contain familiar scenes are better and all changes introduced should be of familiar ideas in order to take advantage of this fact.