The influence of vigorous versus mild exercise on autistic stereotyped behaviors

Journal o f Aut&m and Developmental D&orders, Vol. 14, No. 1, 1984

The Influence of Vigorous versus Mild

Exercise on Autistic Stereotyped Behaviors 1

Lynn Kern, Robert L. Koegel, 2 and Glen Dunlap University o f California, Santa Barbara

A major problem encountered in many autistic children is their high rate o f stereotypic behavior, which has been shown to interfere with on-task responding and other appropriate behaviors. Since the experimental literature indicates that physical exercise can positively influence both appropriate and inappropriate behaviors, including the children's stereotypic behaviors, the purpose o f this study was to investigate whether the specific type o f exercise (i.e., mild vs. vigorous) would differentially affect subsequent stereotyped behaviors. The results demonstrated that (1) 15 minutes o f mild exercise (ball playing) had little or no influence on the children's subsequent stereotyped responding, and (2) 15 minutes o f continuous and vigorous exercise (jogg&g) was always followed by reductions in stereotyped behaviors. These results are discussed in relation to cognitive, physiological, and educational implications.

Numerous studies have suggested that certain highly stereotyped mannerisms (such as hand and arm flapping, body rocking) of autistic and other severely handicapped children may be detrimental to these children's development (cf. Epstein, Doke, Sajwaj, Sorrell, & Rimmer, 1974; Koegel & Covert, 1972; Koegel, Firestone, Kramme, & Dunlap, 1974; Lovaas,

~This research was supported by United States Public Health Service research grants MH 28210 and MH 28231 from the National Institute of Mental Health, and by Research Contract No. 300-82-0362 from the U.S. Department of Education-Special Education Program. The authors are grateful for the contributions of Diane Gilcbrist, Julie Martin, Karen Sallus, Lynne Bonngard, Bill Krutzen, Lee Kern, John Burke, and Rob O'Neill.

2Address all correspondence to Robert L. Koegel, Social Process Research Institute, University of California, Santa Barbara, California 93106.

57 0162-3257/84/0300-0057503.50/0 �9 1984 Plenum Publishing Corporation

58 Kern, Koegel, and Dunlap

Litrownik, & Mann, 1971). Because of this, there have been many attempts to reduce such stereotyped mannerisms. Most of these attempts have involved the manipulation of response consequences (e.g., Baumeister & Forehand, 1973; Bucher & Lovaas, 1968; Foxx & Azrin, 1972; Harris & Wolchik, 1979; Luiselli, 1981; Luiselli & Krause, 1981; Mulhern & Bau- meister, 1969; Rincover, 1978; Sachs, 1973).

However, in order to more fully understand the nature of stereotypic responding, researchers have also begun to manipulate antecedent events. One such promising line of investigation involves the use of antecedent physical exercise to assess its influence on subsequent stereotypic responding (cf. Kern, Koegel, Dyer, Blew, & Fenton, 1982; Ohlson, 1978; Watters &Watters, 1980). While many exercise programs have now been shown to have positive influences on a variety of behaviors in numerous populations, there have also been suggestions that certain types and/or amounts of exercise may be more beneficial than others (cf. Allen, 1980; Dodson & Mullens, 1969; Gupta, Sharma, & Jaspal, 1974). Therefore, the purpose of the present investigation was to systematically manipulate two types of physical exercise -- a vigorous and continuous exercise (jogging) versus a much less vigorous exercise (ball playing) - and to assess whether these activities would differentially influence the children's subsequent stereotypic (and other) responding.

M E T H O D

Subjects

Three children, 7, I l, and 11 years of age, participated in the study. They were diagnosed as autistic by two independent diagnosticians, em- ploying the U.S. National Society for Children and Adults with Autism criteria (NSAC, 1978). They were selected for this experiment because they exhibited especially high levels of stereotypic behaviors. They were formally untestable on standardized intelligence tests. However, they were estimated to have Social Quotients of 80, 60, and 22, respectively, with the Vineland Social Maturity Scale. Prior to treatment, all three children were judged by a physician as being in good physical health, and capable of the physical activities employed in this investigation.

Settings

Two settings were employed in this study: (1) a large open field and (2) a living room. First, following the baseline measures, the physical activity

Vigorous versus Mild Exercise 59

(jogging and ballplaying) periods took place in a large open field, approximately 150 x 150 meters, which was located just outside the building where data were recorded.

Immediately preceding and following each period of physical activity, the children's levels of stereotypic responding were recorded in the second setting. This setting was a 3 • 4-meter room that was furnished as a living room with sofas, chairs, tables, and pictures on the walls. Several age- appropriate toys were scattered around the room, and one adult who was unfamiliar to the child was seated in the room for safety precautions. (No situation occurred that required a response from the adult during the experiment.) The data recorders observed from a separate room, connected by a one-way window and an intercom system.

Experimental Design

A simultaneous-treatments design (Hersen & Barlow, 1976; Kazdin & Hartmann, 1978) was used in which sessions of one condition (e.g., jogging) were alternated with sessions of the other condition (e.g., ball playing). The order was balanced such that the first condition presented per day was alternated across days and across children. Specifically, following the daily baseline condition (1 hour of observation without any antecedent exercise program), one of the two experimental conditions (jogging or ball playing) was implemented. After 15 minutes of one activity (e.g., jogging), the child was observed for a 90-minute period in the experimental setting. Then, the other condition (e.g., 15 minutes of ball playing) was implemented and again followed by 90 minutes of data recording. Finally, the first condition conducted for that child on that day was repeated (e.g., 15 minutes of jogging followed by 90 minutes of observation).

Independent Variable: Type of Physical Exercise

Vigorous Exercise-Jogging. In each (noncontingent)jogging session a randomly selected adult from a pool of eight (naive to the experimental hypothesis) and a child jogged side by side (holding hands if the child began to stray from the area). No direct interventions were made with respect to any of the children's stereotypic behaviors. The jogging pace was adjusted in each session to be mildly strenuous (e.g., child showed increased breath- ing rate and/or slightly flushed face) but was slowed to a temporary walk (approximately 15 seconds) if the child began to show any observable signs


of discomfort (e.g., appearing out of breath or attempting to pull away from the adult's hand). Throughout the sessions the adult occasionally reinforced the child verbally for running (e.g., "Good running"). The total length of the jogging period (not counting the occasional 15-second walks) was 15 minutes.

Mild Exercise--Ball Playing. During each (noncontingent) 15-minute ball-playing session an adult (from the above pool) interacted by gently throwing a large (20 cm) soft rubber ball to the child. A distance of approximately 2 to 3 meters was maintained between the child and the adult during the sessions. In addition, a second adult stood directly behind the child in order to manually prompt the child to put his/her arms up to catch the ball and to remain in the area, if necessary. The rate of throwing the ball was approximately 10 to 20 times per minute (depending on how quickly the child caught/threw the ball). In instances when the child made no attempt to catch or return the ball, the adult would pick up the ball and gently throw it to the child. Correct ball-playing responses were verbally reinforced by the adult.

Dependent Variable: Stereotypic Behaviors

The term stereotypic behaviors was defined as follows: repetitive, stereotypic responses that appeared to be performed for the purpose of providing sensory input, but that did not appear to produce any obvious effects on the child's social environment (Dunlap, Dyer, & Koegel, 1983; Hutt, Hutt, Lee, & Ounsted, 1965; Lovaas, 1967). This category was operationally defined for each individual child on the basis of prior non- experimental observations (see Table I). These specific behaviors are considered symptomatic of the syndrome of autism and other severe handicaps (cf. Berkson, 1967; NSAC, 1978; Schopler, 1978) and are typically not seen to any large extent in normal populations.

Measurement

Each observation period was divided into 15-minute blocks, with data recorded during the first 5 minutes of each block. Thus, each 1 hour baseline period contained four blocks and each period following a physical activity contained six blocks. A time-sampling recording procedure was utilized in which 15-second intervals were divided into 5 seconds of observation and 10 seconds of data recording, resulting in 20 intervals per 5-

Vigorous versus Mild Exercise

Table 1. The Autistic Stereotyped Behaviors Recorded for the Three Children Who Participated in This Experiment

61

Autistic stereotyped behaviors

Child 1.

2.

3. 4. 5. 6. 7.

8. 9.

10.

Child 2 1. 2. 3.

Child 3 1.

2. 3.

1 Intense staring or gazing (a fixed, glassy-eyed look lasting more than 3 seconds) Spontaneous loud and repetitive glottal and gutteral vocalizations with hands placed in a cupped position next to ears Loud, high-pitched, repetitive nasal vocalizations Gazing intently at hand placed within 6" of eye Repetitive breathy whistles, accompanied by hyperventilation Flapping hands in air Repetitive head or body shaking (small rapid movements from side to side) Repetitive jerking of body Repetitive saliva fingering Vigorous forward and backward rocking

Prolonged and/or repetitive lip puckering Repetitive, stereotypic finger flexing and arm waving at shoulder level Repetitive, continuous babbling of nonsense syllables

Repetitive, stereotypic finger flexing (often while simultaneously gazing at them) Arm and hand flapping Stereotyped repetitive delayed echolalia (e.g., repeating a command several times)

minute block of observation. Observers recorded the presence or absence of stereotypic responding on precoded data sheets with a plus if the behavior category occurred and a minus if it did not occur.

Reliability

Two observers (one naive to the purpose of the experiment) in- dependently recorded occurrences and nonoccurrences of stereotypic behavior during 77 (58.33~ randomly selected sessions. All observers were given lists of the children's behaviors. Then, prior to the first formal reliability session, approximately five practice sessions were held to ensure that each observer was accurately recording the data according to the experimental definitions. Percent agreement was calculated for the formal reliability sessions on an interval-by-interval basis. An agreement consisted of the two observers recording exactly the same response. Percent agreement was calculated for each interval by dividing the number of agreements by the number of agreements plus disagreements. The average percent


I 0 0 -

9 0 -

80-

70 -

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40- - r 30- ILl I ~ ZO-

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I O -

. . . I 0

r~ t.l.I I--- Z I00 -

9 0 - I.I- 0 so-

I-- 70. z 60- t.t.I r 50- Ix:

4 0 - 0. .

30

20

fO

0

BASE dOG BALL dOG BASE BALL dOG BALL

/ / /

i i /

1 1 1

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/ i /

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/ / . . .

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\ N \ \ \ \

\ \ \ \ \ \ I

z z z

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/ 1 1 I / I / / /

/ / / / / /

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/ / / / i .*

\ \ \ \ \ \ \ \ \ \ \ \

\ \ \ \ \ x \ \ \ \ \ \

x \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \

CHILD I

BASE BALL dOG BALL BASE dOG BALL dOG

r

r

/ / / / / / / / /

I / /

I I I

, - - -

J ~.~.~ J /.C."

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/ / / / / z / / / / / / / / r / / /

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CHILD 2

BASE dOG BALL dOG BASE BALL dOG BALL

/ / i / / / / / / / / /

/ . , . . , . / / /

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/ / / i i 1 / / i / / / z / i / 1 1

[ N X \

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/ / / / / / / / / / / / / / / / / / / / / / / / , / . / /

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~-,,?

\ \ \ \ \ \ \ \ \ \ \ - , \ \ \ \ \ x \ \ \ / CHILD ~5

DAY I DAY 2__

Fig. 1. The percent of intervals with autistic stereotyped responding for children 1, 2, and 3 during the l-hour baseline conditions, for 90 minutes following the jogging exercise sessions, and 90 minutes following the ball-playing exercise sessions.


Table 11. Percent of Autistic Stereotyped RespondingLBehavior during 15-Minute Sessions for Each of the Children

Day 1

% Autistic stereotyped responding

% Autistic stereotyped responding

Day 2

Child 1

I 2 3 4 5 6 7 8 9 10

90 85 90 90 45 10 45 45 35 65

11 12 13 14 15 16

75 55 60 25 80 85 r

I 2 3 4

070Autistic 85 90 85 851 ~ l I ~ 1 stereotyped responding

11 12 13 14 15 16

% Autistic 40 40 90 70 85 100 I "-~[ stereotyped = "~ responding

Child 2

Day 1

I 2 3 4

% Autistic 85 75 75 85 I ~ ] stereotyped responding ~ "~ I

07o Autistic stereotyped respond ng

Day 2

I 0 T0 Autistic stereotyped responding

~ Autistic stereotyped responding

11 12 13 14 15 16

55 25 65 65 90 80

1 2 3 4 75 90 75 75

11 12 13 14 15 16

55 90 45 65 80 85

17 18 19 20 21 22

75 60 35 55 55 75

5 6 7 8 9 10

85 95 100 100 90 75

17 18 19 20 21 22

70 95 85 90 100 100

5 6 7 8 9 10

75 80 60 35 75 65

17 18 19 20 21 22

I "-~l I :,o195._~ 90 90 65 70 85

R

17 18 19 20 21 22

=~ 155 75 80 75 70 70 ]

I 1

5 6 7 8 9 10


Table Ii. Continued

Day 1

Child 3

I 2 3 4 5 6 7 8 9 10

40 40 40

11 12 13 14 15 16 18 19 20 21 22 65 80 55 85 80 100 45 35 75 90 80

17

15~ 1 070 Autistic stereotyped respond ng

Day 2

~ Autistic ] stereotyped

responding

1 2 3 4 5 6 7 8 9 10

70 90 75 85 1l=.~,l~._~170 85 95 80 95 85 [ .~

11 12 13 14 15 16 17 18 19 20 21 22

[]%AutistiCstere~176 50 30 65 40 45 95 [ ~180 [ "~['- 90 100 80 80 85 ]i

agreement for recording stereotypic responding across the 77 sessions was 97.70~ (range: 90~ to 100~

RESULTS

The results of the simultaneous-treatments analyses with all three children are shown in Figure 1. The graph shows that all three children had high levels of stereotypic responding prior to the exercise. For example, the average baseline level of such responding for Child 1 was 88.75O7o. A decrease was then evidenced as a result of the jogging sessions. That is, on day 1 Child l's stereotypic responding decreased from a baseline of 88.75~ to 40O7o following jogging. A similar pattern is evident for each of the other children, and, in fact, in all nine of the instances after jogging was in- troduced, stereotypic responding decreased below baseline levels.

In contrast, there were no systematic changes following the ball- playing sessions. For example, inspection of Child 2's results for day 1 and


day 2 shows that levels of stereotypic responding following ball playing were sometimes lower and sometimes higher than the corresponding baseline levels. This was true for each of the other children with, in total, six of the nine ball-playing conditions showing levels exceeding baseline.

In order to permit examination of individual trends in the data, (e.g., note that stereotypic responding usually reached its low point within about 1 hour following jogging), Table II presents the individual data for each successive 15-minute observational period.

DISCUSSION

These results showing that vigorous exercise (jogging) systematically produced decreases in stereot)~pic responding are consistent with those in a number of previously reported investigations. In addition, the present data on autistic stereotypies add to the literature by demonstrating that the specific type of physical activity appears to have a differential impact on the subsequent behavior of autistic children.

A number of studies, including those documenting increases in appropriate responding (e.g., Diesfeldt & Diesfeldt-Groenendijk, 1977; Dodson & Mullens, 1969; Kern et al., 1982; Schaney, Brekke, Landry, & Burke, 1976), indicate that fatigue is probably not the mechanism primarily responsible for the positive effects of vigorous exercise (cf. Bachman, 1982) but rather that some other behavioral/physiological mechanism(s) are involved. This seems especially interesting since a number of authors (e.g., Blackstock, 1978; Coleman, 1979; Damasio & Maurer, 1978; Ornitz & Ritvo, 1968; Rutter & Bartak, 1971; Schopler & Reichler, 1971; Student & Sohmer, 1978; Tanguay, 1976; Wetherby, Koegel, & Mendel, 1981) have suggested that physiological mechanisms may be involved in the etiology and behavioral characteristics of autism. It can be speculated that vigorous exercise may directly influence the functioning of such variables as physiological arousal (e.g., Hurt & Hutt, 1968; Ornitz & Ritvo, 1968; Rimland, 1964) or the production and release of neurotransmitters or beta-endorphins (cf. Fraioli et al., 1980; Kline & Lehmann, 1979, VonEuler, 1974).

Whatever the specific mechanism is that underlies the present phe- nomenon, it may be important to note that many educational programs do not provide even brief periods of physical exercise. Further, of those that do provide some activity, most do not systematically provide for any given type of activity. Thus, further research and programming in this area may be an especially important concern of teachers and other practitioners involved with autistic or other handicapped children.


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The influence of vigorous versus mild exercise on autistic stereotyped behaviors

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