5. Fatigue and Adjustments to Individual Differences [MÜNSTERBERG, Hugo, Psychology-General and Applied, pp. 384-385, New York, D. Appleton & Co., 1916.]

The most important influence of negative character is fatigue No true success can be bought by the psychophysical exhaustion of the pupils. Both the stages of fatigue and the most economical restoration of the mental energies can be examined by experimental methods. A frequently used test requires the children to fill blanks in a story. The printed page contains open spaces for syllables or letters which the child is to supply. His attention to the content is needed in order to perform the task, and the rapidity and correctness with which the test is carried out indicate the degree of efficiency of those mental functions which are central in the regular school work. The fatigue of attention can also be quickly measured by determining the correctness of calculation. The mere rapidity of calculation may increase steadily, in spite of the fatigue, because the influence of the training prevails, but the increase of the mistakes is far greater. Frequently indirect methods are applied which measure not the fatigue itself, but its psychophysical symptoms.

The objective measurement of fatigue is pedagogically the more important, as the subjective feeling of fatigue is rather unreliable. A feeling of fatigue may come up habitually after a small amount of effort before any undesirable effect on the central nervous system is to be feared. The child who associates this illusory feeling of fatigue with all earnest labor must learn to overcome the slight weariness by new effort. On the other hand there are not a few who are liable to approach dangerous exhaustion without any marked feeling of fatigue. A neurasthenic disturbance may indicate later that the safety point was passed without any inner danger signal. The experiments seem to indicate that mathematics and those lessons which involve physical activity such as physical exercise and singing have the greatest fatiguing influence, next to them the languages, after them the naturalistic sciences, and then the technical subjects. While the fatigue steadily grows, yet it is not wise to put the most difficult subjects into the beginning of the day as the first period is needed for the adjustment and warming up. But certainly the last hours of the day ought to be left open for the easiest subjects. The younger pupils become fatigued much more rapidly than the older ones. But, above

all, a pupil is the more fatigued by a piece of work the less able he is to master it.

6. Important Results of Fatigue Accompanying School

Work

[COLVIN, Stephen S., The Learning Process, pp. 275-280. Copyright, 1917, by the Macmillan Co.] (Adapted.)

The most important results of the different tests of fatigue and ennui accompanying school work may be summarized as follows:

1. There is considerable experimental evidence that injurious fatigue is not common among school children. It is quite probable that the whole question of fatigue in the schools has been greatly over-estimated. It is true, however, that there is often a feeling of boredom and lassitude, but these are primarily due to the tediousness of the situation, or the lack of interest. Regardless of their cause, they should be remedied.

2. Another effective remedy for so-called mental fatigue is the ignoring of feelings of weariness and distraction. The younger the child is, the more likely he is to quit work at the onset of the tired feeling. He should be taught to habituate himself to ignore such conditions. Experiments show that if he were to continue his work for an hour or two many of these symptoms of weariness would disappear. He would have what James calls "second wind." At least as far as adults are concerned, there is little foundation for the prevalent belief that they cannot continue for long periods of time to do efficient mental work. With children, however, it is probably unwise to demand of them sustained attention over long periods of time. The pupils have not accustomed themselves to ignore the accompanying ennui that makes the work distasteful and, consequently, ineffective. On the other hand, there is the possibility of the child being injured by real fatigue.

3. Pleasant work seems to be much less fatiguing than unpleasant. This is probably due to the fact that pleasure tends to activate the vitality of an organism, and displeasure to lower it. Furthermore, the tests for fatigue do not distinguish between physiological fatigue and mere dissatisfaction, unwillingness to do the work, or the lack of interest in it. These latter factors do not exist when the work is pleasant.

4. Physical work is apparently more fatiguing than mental

work; consequently, pupils get very little relief from mental activities by engaging in gymnastics or similar activities. Whether the fatigue be mental or physical, the remedy appears to be complete rest. Furthermore, since some of the mental fatigue is due to interest in the work, a change from mental to physical work may bring relief.

5. Learning conducted on the level of habit seems less fatiguing than learning with sustained attention. The greater demand the activity makes on active attention, the greater appears to be the waste in physical energy due to distraction.

6. When fatigued, the individual is less capable of forming associations and thinking. Work of any high degree of significance cannot be accomplished when the person is fatigued or when he is suffering from the irksomeness of his task. On the whole, experiments seem to indicate that the afternoon hours are somewhat less favorable to school work than the morning hours and also that the first hour of the morning is not so effective as those immediately following.

7. Normal fatigue resulting from the performance of school activities is quite different from the symptoms of mental fatigue found in the case of nervous exhaustion. The former type of fatigue is a normal experience, while the latter type which accompanies nervous exhaustion requires the services of a specialist.

8. The teacher can guard against the fluctuations of attention and the distractions attendant upon mental work by organizing the activities so that they present a system of related and meaningful parts.

7. Fatigue

[ASH, Isaac Emery, "Fatigue and Its Effects Upon Control," Archives of Psychology, University of Wisconsin Contributions to Educational Psychology, Nov. 1, 1914. New York, The Science Press.] (Abstract.)

Fatigue is a comprehensive term which embraces immediate and temporary changes of either functional or organic character as a result of activity within the organism itself. Fatigue lessens the further activities of the organism. Fatigue produces a loss of efficiency in the worker and a lessening of the capacity to do work.

The amount of fatigue is dependent not only on the amount of work done but also on the particular mental state of the worker. Health, nutrition, interest, temperature, light and

time of day have important bearings upon fatigue. Due to the fact that muscular fatigue lends itself better to direct observation and experimentation than does mental fatigue, the phenom ena of muscular fatigue are better known than mental fatigue.

One investigator claims to have isolated fatigue toxins from the muscle tissue of dogs. These fatigue toxins when injected into the body of a rested dog produce all of the symptoms of natural fatigue. Muscular contraction produces chemical changes within the muscle tissue. The carbohydrates in the muscle tissue decomposes and forms certain toxic substances, among which the most important are lactic acid, creatin and carbon dioxide. Various other reasons have been assigned for the explanation of fatigue, such as: (1) The motor nerve endplates within the muscles yield first to fatigue. Fatigue of the motor end-plates serves as a protection to the muscles against the complete impoverishment of energizing substance. (2) Due to a condition of the central nervous system in order to prevent a depletion of the nervous energy of the entire organism. (3) The connection between the different neurones is not one of continuity but of contact. This point is the synapse and is the first incidence of fatigue.

All of the theories of the conditions of fatigue place a great emphasis on the mental attitude of the worker. Interesting work is easier because interest makes available greater stores of energy, or because it supplements effort, or because it helps the physico-chemical processes in changing potential energy to the active state. When one is interestingly engaged, irrelevant suggestions and external stimuli fail to distract one's attention. If the work is uninteresting every stimulus brings about some form of conscious reaction.

Investigators in the problem of mental fatigue are confronted with trying to measure something without an objective measuring unit. The above fact accounts for fewer investigations on mental fatigue than on physical fatigue.

8. Reserves of Energy

[LEE, F. S., "Physical Exercise from the Standpoint of Physiology," Science, April 2, 1909, New Series, Vol. 29, pp. 521, 527.]

It is now well substantiated that "moderate but increasing amounts of exercise, producing moderate but increasing amounts of fatigue substances, put the tissues into a state of tolerance or resistance, such that when the supreme effort is demanded of

them, they do not succumb. He who wins is he who can best resist the poisons of fatigue." Training then is nothing more or less than producing resistance to fatigue products. In the same way as the individual becomes adapted to a drug and more or less immune to large doses, he may develop immunity to fatigue substances. Therefore, as James suggests, one should endeavor to extend the boundaries of one's endurance, always stopping before exhaustion is reached, but doing a little more each day.

9. The Energies of Men

[JAMES, William, On Vital Reserves, pp. 6–7. New York, Henry Holt, & Co., 1911.]

James in the introductory paragraph of his remarkable essay opens up to us new "levels of energy" which are usually "untapped." He writes:

Everyone knows what it is to start a piece of work, either intellectual or muscular, feeling stale or cold, as an Adirondack guide once put it to me. And everybody knows what it is to "warm up to his job." The process of warming up gets particularly striking in the phenomenon known as "second wind." On usual occasions we make a practice of stopping an occupation as soon as we meet the first effective layer (so to call it) of fatigue. We have then walked, played, or worked "enough," or we desist. That amount of fatigue is an efficacious obstruction on this side of which our usual life is cast. But if an unusual necessity forces us to press onward, a surprising thing occurs. The fatigue gets worse up to a certain critical point, when gradually or suddenly it passes away, and we are fresher than before. We have evidently tapped a level of new energy, masked until then by the fatigue-obstacle usually obeyed. There may be layer after layer of this experiA third and a fourth "wind" may supervene. Mental activity shows the phenomenon as well as physical, and in exceptional cases we may find, beyond the very extremity of fatigue-distress, amounts of ease and power that we never dreamed ourselves to own,-sources of strength habitually not taxed at all, because habitually we never push through the obstruction, never pass those early critical points.

ence.

Again Professor James says:

Of course there are limits; the trees don't grow into the sky. But the plain fact remains that men the world over possess