A Study of the Effects of an Interrupted School Week on Fatigue in Fourth-Grade Schoolchildren

N. B. Bushanskaya

Department of Hygiene of Children and Adolescents
Leningrad Sanitary-Hygienic Medical Institute

It has been demonstrated that fatigue in schoolchildren increases considerably toward the end of the school day, week, and year. To prevent fatigue, a number of authors (L. I. Figlin, E. M. Vainrub, and L. Ya. Subotkevich) in re-

…As a result of experimental observations, it was proposed that lessons in the first grades be shortened to 35 minutes, written homework be abolished (N. N. Preobrazhenskaya), and outdoor recreation be arranged for pupils (L. V. Mikhailova). Among the works available to us, we found no studies examining pupils’ work capacity when an additional day free from lessons is introduced in the middle of the week. The time is not far off when our country will have the shortest working week, including an additional second day off.

Our aim was to study pupils’ physiological responses and changes in their work capacity when a day free from lessons was introduced in the middle of the week without changing the curriculum. Observations were conducted from January 1 to June 1, 1959, in two fourth-grade classes—an experimental class and a control class—at School No. 135 in Leningrad.

In the experimental class, a modified school schedule was introduced, giving pupils Thursday free from lessons. On that day, they visited museums, went on excursions in the vicinity of the city, engaged in physical education, and performed socially useful work on the school grounds. No homework was assigned for Thursday; the children prepared Friday’s lessons on Wednesday.

The sanitary and hygienic conditions in the two classes during lessons and breaks were identical and entirely favorable. The pupils’ health and physical development were assessed as entirely satisfactory. The curriculum remained the same for both classes, but the number of lessons in the experimental class was reduced by one geography lesson and one natural science lesson per week. The pupils did the physical education prescribed by the curriculum on Thursdays on the school grounds—in winter, skiing and skating.

The effect of the school schedule on higher nervous activity was studied by recording changes in the latency of responses to stimuli of different intensities, using a chronoscope-type instrument modified by A. V. Livshits and designed and manufactured in the workshops of the Leningrad Sanitary-Hygienic Medical Institute. During each test, 20 signals \((З_1, С_1, З_2, С_2)\) were presented¹ in a fixed sequence that was maintained throughout the observation period. In analyzing the data, response latencies to strong and weak stimuli were compared pairwise. The 20 stimuli presented to each subject yielded 30 such comparison pairs: 8 pairs each of \((С_1, С_2)\) and \((З_1, С_2)\), and 7 pairs each of \((З_1, З_2)\) and \((З_2, С_2)\).

Under normal cerebral cortical response, the latency of the response to strong stimuli is shorter. When increased demands are placed on the central nervous system—for example, by an improper schedule or an increased academic workload—the latency for a strong stimulus may become equal to, or even greater than, that for a weak stimulus, owing to the development of protective inhibition in the cerebral cortex. Such a response is termed an equalizing or paradoxical response, respectively.

Ten pupils were studied: five from the experimental class and five from the control class. Each observation consisted of two tests, one before the start of the school day and one after its end, on the same days of the week: Tuesday, Thursday, and Saturday. A total of 270 observations were made.

A letter-cancellation test was used to assess changes in the group’s work capacity. Changes in health and physical development, as well as illness during the observation period, were also studied.

The findings showed that the academic workload produces changes in pupils’ work capacity and physiological responses. At the beginning of the school week, the number of paradoxical responses increases only slightly by the end of lessons (Fig. 1) in both the control and experimental classes. At the end of the school week, the number of paradoxical responses increases considerably, particularly in the control class (Fig. 2), indicating reduced functional endurance of the cortical nerve cells.

As Figs. 1 and 2 show, throughout the observation period the pupils in the experimental class had fewer paradoxical responses both before lessons began and at the end of the school day. Normal…

…reactions among pupils in the experimental class was higher (70–76.8%) than among those in the control class (61.7–69.9%). The decline in the number of normal reactions and the increase in paradoxical reactions over the course of the school day were considerably less pronounced among pupils in the experimental class than among those in the control class.

The difference in the change in pupils’ capacity for work was particularly marked on Saturday: by the end of the school day, phase reactions accounted for 38.3% of reactions in the control class, including 33.1% that were paradoxical, whereas in the experimental class 18.2% of reactions were paradoxical (see Fig. 2). By the end of the school day, the number of paradoxical reac—

Fig. 1. Changes in the numbers of normal (\(Н\)), equalizing (\(У\)), and paradoxical (\(П\)) reactions during the school day among pupils in the experimental and control classes at the beginning of the week.

\(а\)—before classes; \(б\)—after the school day; 1—experimental class; 2—control class.
Vertical axis: Number of reactions (percent).

Fig. 2. Changes in the numbers of normal (\(Н\)), equalizing (\(У\)), and paradoxical (\(П\)) reactions during the school day among pupils in the experimental and control classes at the end of the week.

\(а\)—before classes; \(б\)—after the school day; 1—experimental class; 2—control class.
Vertical axis: Number of reactions (percent).

—tions in the control class had increased by 13%, mainly at the expense of normal reactions, which decreased by 8.2%. In the experimental class, by contrast, paradoxical reactions increased by 8.4% at the expense of equalizing reactions, while normal reactions decreased by only 3% (Fig. 2).

A series of observations conducted on Thursdays showed that, in the experimental class, the number of normal reactions increased by 2.7% after the pupils had spent time on the school grounds. In the control class on the same days, the number of normal reactions decreased by 10.4% by the end of the school day, while paradoxical reactions increased by 6.2%. In individual pupils in the control class, the number of paradoxical reactions increased fourfold by the end of classes. For example, the following results were obtained for pupil O. K. on March 19, 1959: before lessons, at 8:30 a.m., \(Н_{26}У_1П_3\); after lessons, at 1:30 p.m., \(Н_{17}У_1П_{12}\) (\(Н\)—normal, \(У\)—equalizing, \(П\)—paradoxical reactions).

This indicates a sharp deterioration in the state of higher nervous activity in pupil O. K. by the end of the school day.

The latency of responses to the same stimuli increased by the end of the school day, indicating a reduction in the excitability of the cerebral cortex. Among pupils in the experimental class, the response latency to strong stimuli (loud sound and bright light) increased by 8–30 milliseconds; among those in the control class, it increased by 20–74 milliseconds.

An investigation of pupils’ capacity for work using the proofreading method showed that the amount of work completed by pupils in the two classes was the same; the number of printed characters scanned by one pu—

Table 1

Changes in pupils’ work capacity relative to baseline during the school day
(Mean data for February 12 and March 7, 1959)

…per pupil before lessons averaged 638–678, and after lessons, 462–477 (Table 1).

By the end of lessons, the number of printed characters examined by pupils in the experimental class decreased by 176, whereas for pupils in the control class it decreased by 201.

The work was performed somewhat better in the experimental class: the number of errors, omissions, and corrections per 1,000 characters examined was 5.6–5.7, compared with 7.4–7.6 in the control class.

Table 2

Mean increases in measures of physical development among pupils in the experimental and control classes during the observation period
(January to June 1959)

Changes in health status and physical development were very small, but a tendency toward greater increases in certain measures of physical development can be noted among pupils in the experimental class compared with those in the control class (Table 2).

Vital capacity of the lungs increased by an average of 136 mL among pupils in the experimental class and by 45 mL among those in the control class (mean values for all observations). Over the same period, the mean hemoglobin content of pupils in the experimental class increased from 78% to 82%, while that of pupils in the control class remained unchanged (77%).

The study of morbidity showed that the rate of overall illness, and particularly of colds and related illnesses, was lower among pupils in the experimental class than among those in the control class (Table 3).

During the observation period, 33.3 cases of colds and related illnesses, including influenza, were recorded per 100 children in the experimental class, compared with 100 cases in the control class.

During the second half of the school year, each pupil in the experimental class missed an average of 4.1 days, compared with 7.4 days in the control class.

The reduction in colds and related illnesses among pupils in the experimental class may be explained by their spending more time outdoors during the part of the day free from lessons and by their outdoor physical education classes throughout the six-month observation period. These practices helped to condition the body and increase its resistance to adverse environmental factors.

Table 3

Number of illnesses experienced by pupils in the experimental and control classes from January 1 to June 1, 1959 (per 100 pupils)

An examination of academic performance during the second half of the 1958/59 school year showed that, by the end of the school year, performance in the experimental class had not declined from the previous half-year (95%), standing at 95.3%. The curriculum was completed.

Conclusions

1. Under the ordinary school schedule, the academic workload causes disturbances in cortical dynamics among fourth-grade pupils. These are manifested in an increased number of phase reactions, a lengthening of the latency period of responses, and reduced working capacity.

2. Under the modified school schedule, with a day free from classes introduced in the middle of the week, disturbances in cortical dynamics are considerably less pronounced. This difference is particularly evident at the end of the week.

3. The modified school schedule is associated with a tendency toward improvement in several indicators of health and physical development, as well as a substantial reduction in the number of colds.

4. The observations showed that a school schedule incorporating a day free from classes in the middle of the week (Thursday), while retaining the curriculum, was more favorable. Academic performance does not decline under the new schedule.

References

Bogachenko, L. S. Journal of Higher Nervous Activity, 1953, vol. 3, p. 203. — Vainrub, E. M., and Subotkevich, L. Ya. In: Problems of Community and School Hygiene. Kyiv, 1956, p. 254. — Ivanov-Smolenskii, A. G. Methods for Studying Conditioned Reflexes in Humans. Moscow, 1933. — Kaplun, E. G., and Redkina, E. K. In: Problems of Age-Related Morphology and Physiology. Moscow, 1953, issue 1, p. 141. — Mikhailova, L. V. Proceedings of the Academy of Pedagogical Sciences, 1955, issue 66, p. 102. — Nusbaum, D. G. In: Problems of School Hygiene. Moscow, 1959, p. 107. — Pratusevich, Yu. M. Hygiene and Sanitation, 1956, no. 2, p. 43. — Preobrazhenskaya, N. N. In: Hygiene of Children and Adolescents. Leningrad, 1958, p. 22. — Figlin, L. I. In: New Data on the Hygiene of Children and Adolescents. Moscow–Leningrad, 1956, p. 41.

Received December 29, 1959.

A Study of the Effect of an Interrupted School Week on Strain in Fourth-Grade Schoolchildren

N. B. Bushanskaya

The study was conducted from January to June 1959 in two fourth-grade classes, one experimental and one control. Its aim was to investigate the physiological responses of schoolchildren to the introduction of an additional day off in the middle of the week. Physiological, clinical, and hygienic methods were used.

The results showed that, under the ordinary weekly schedule, the children developed pronounced disturbances in cortical dynamics as a result of strain. These included an increase in the number of paradoxical reactions and a lengthening of the latent period of responses to various stimuli, including light and sound.

The introduction of a modified weekly schedule in the experimental class considerably reduced disturbances in cortical dynamics. Normal reactions accounted for 70–76% of reactions, compared with 61% in the control class, while paradoxical reactions increased to 18–20%, compared with 33.3% in the control class.

Among the children in the experimental class, the incidence of colds fell, and some health indicators showed a definite tendency to improve.

1. \(З_1\)—strong sound; \(С_1\)—strong light; \(З_2\)—weak sound; \(С_2\)—weak light. ↩