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Operant Conditioning of Speech and Language in the Nonverbal Retarded Child Recent Advances
Symposium on Habilitation of the Handicapped Child
Operant Conditioning of Speech and Language in the Nonverbal Retarded Child Recent Advances
Philip W. Drash, Ph.D., * and J. Michael Leibowitz, M.A. **
Within recent years the science and associated technology of behavior modification and control in humans has shown rapid growth and development. Operant procedures are now routinely and successfully used in the treatment of a wide variety of behavior disorders by pediatricians, psychiatrists, psychologists, educators, nurses, social workers, and others. Operant procedures have proven especially beneficial in the remediation of routine behavioral disorders and deficiencies in the retarded child and are now employed as integral parts of the treatment program in many clinics, hospitals, and residential settings. One of the more significant recent developments within the field of behavior modification has been the development of systematic procedures for the operant conditioning of speech and language in nonverbal and verbally deficient children. Many pediatricians, speech pathologists, psychologists, psychiatrists, and others have recognized the significance of marked speech and language delay in the young child during the first 3 years of life. Until very recently, however, there was available to the pediatrician no systematic treatment program for habilitation of such children. Because of the lack of effective treatment techniques, pediatricians have in the past frequently adopted a "wait-and-see" attitude, hoping that the child with marked speech and language delay at about 2 years might spontaneously develop speech by 3 or 4 years. While an occasional child may acquire normal language as late as 4 years, such a case is, unfortunately, the exception. More commonly the child who shows marked "Director, Psychological Services, The John F. Kennedy Institute; Assistant Professor of Medical Psychology and Pediatrics, The Johns Hopkins University School of Medicine **Associate Director, Psychological Services, The John F. Kennedy Institute; Instructor in Pediatrics, The Johns Hopkins University School of Medicine Supported in part through Project 917, Maternal and Child Health Services, U.S. Department of Health, Education and Welfare.
Pediatric Clinics of North America- Vol. 20, No.1, February 1973
233
234
PHILIP
W.
DRASH AND
J.
MICHAEL LEIBOWITZ
,
speech and language deficiency at 2 to 3 years will continue to show mild to severe developmental retardation without treatment,! In this article we will familiarize the pediatrician with recent developments in behavior modification which make available to him, for the first time, operant treatment programs for habilitation of the young verbally deficient child, and will acquaint the pediatrician with the extremely important role he plays in the early identification and referral of verbally deficient children.
IDENTIFICATION, SCREENING, AND REFERRAL OF THE CHILD Much has been written from the medical standpoint regarding identification of the high risk child. This section is concerned not with neurological or physiological signs but with behavioral indices which afford the pediatrician clues to assist him in identification of the child with potential developmental disability who may benefit from remedial programs of speech and language conditioning. Many pediatricians are trained in the rudiments of intelligence testing and are familiar with the Gesell Developmental Norms,t3 the Cattell Infant Intelligence Scale,6 and The Bayley Scales of Infant Development." Norms are also available in handbooks such as the Pediatrician's Handbook of Communication Disorders. 20 If the pediatrician has reason to suspect that a child is significantly delayed in language development even as early as 1 year, he should compare the child's language development with several normative tables of language development. A recent study of 2875 infants over a 4 year period revealed that children developmentally delayed 1 month or more at age 8 months had significantly lower IQ scores at ages 4 and 7 years than a control group.1S It is thus clear that even moderate delays in speech development require careful attention by the pediatrician. Once a developmental delay is suspected or established and no clearly defined or severe neurological disease is present, early referral to a psychologist trained in behavior modification procedures may be indicated. While the pediatrician may feel some hesitancy about referring a 1112 to 2 year old child for evaluation, if the results are negative both the pediatrician and the child's parents are relieved of unnecessary worry. Conversely if treatment is indicated, early referral, in our experience, has proven most satisfactory for a number of reasons. First, the child's behavioral deficit is usually smaller at an early age and this increases the probability of therapeutic success. Generally, the more severe the problem, the longer treatment must be administered and the less likely that full remediation will be accomplished. Second, because there is frequently a long delay between referral and professional treatment, very early referral is almost a sine qua non if the treatment program is to be started before 2 or 3 years of age. Third, since the required behaviors a child should engage in increase at a slower rate in the early years, the total accumulated deficit to be overcome will be smaller even if there is a delay
OPERANT CONDITIONING OF SPEECH AND LANGUAGE
235
between referral and treatment. Fourth, early referral decreases the chances that new unacceptable behaviors will be learned which may possibly compete with the learning of speech. It is thus clear that the pediatrician, who is frequently the only health professional in contact with the parents of the young child during the first two or three years of the child's life, plays a crucial role in the initiation of treatment.
BEHAVIORAL EVALUATION OF LANGUAGE DEVELOPMENT Once a referral is made to a behaviorally oriented psychologist, the pediatrician may expect an assessment that includes both a standardized individual intelligence test, such as the Cattell Infant Intelligence Test6 or the Bayley Scales of Infant Development,2 and a diagnostic conditioning evaluation of speech and language. The individual intelligence test will provide the pediatrician with information regarding the child's generallevel of intellectual functioning as compared with other children his age, and may provide some specific information regarding the child's relative strengths and weaknesses. Diagnostic speech conditioning provides an objective index of the child's expressive and receptive language repertoires and also determines what types of environmental stimuli control a child's verbal behavior. The diagnostic conditioning evaluation consists of four parts and allows the psychologist to predict the child's probable rate of progress in an operant treatment program. Included in the diagnostic conditioning evaluation are: (1) A determination of the initial level of the child's expressive language behavior, which is used as a baseline from which therapeutic change is measured; (2) A determination of possible reinforcing consequences, based upon systematic attempts to control the patient's behavior using a variety of reinforcers; (3) Determination of the child's probable progress in the program by attempting to teach new behaviors which did not appear during baseline testing; (4) Assessment of the presence or absence of behavioral problems which might compete with rapid therapeutic change. In some cases the behavioral evaluation may indicate that the child does not require operant speech conditioning but may identify other behavior problems which warrant immediate attention, such as extreme negativistic behavior. Behavior problems are assessed following the same general procedures as above. Techniques for the elimination of the behavior are identified and probable maintaining consequences are determined. An outline of the therapeutic program for the child may then be developed. The results of such behavioral evaluations provide the pediatrician with at least three types of information. The evaluation provides an estimate of the probable therapeutic time needed to modify the behavior in question, it determines if referral to other specialists will be necessary, and it provides the pediatrician with specific therapeutic suggestions for working with the families of those children who do not require intensive operant therapy.
236
PHILIP
W.
DRASH AND
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MICHAEL LEIBOWITZ
THE TREATMENT PROGRAM For those patients who require intensive treatment, the Kennedy program may serve as a model. The operant treatment program for nonverbal children, developed primarily by the senior author with the collaboration of the junior author and other departmental associates, consists of a highly structured expressive language development curriculum containing a series of discrete steps which parallel the development of speech and language in the normal child between birth and approximately 5 to 6 years. An outline of the speech and language C'llrriculum is presented in Table 1. The approximate expressive language age equivalent for the various levels is indicated in the first column. The language age equivalents are extrapolated from the norms of the Binet,30 the Bayley,2 and the Pediatrician's Handbook of Communication Disorders.20 As indicated in Table 1, the program consists of 24 discrete steps which the child must progress through. Each step has a clearly defined criterion level which must be met before the child moves to the next level of the curriculum. This procedure insures that the child has mastered all skills below the specific level on which he may be working. Children are typically treated as inpatients and receive two 1 hour periods of therapy per day by therapists trained in the operant conditioning of speech and language. The typical treatment program extends for a period of 6 to 12 months, the duration of treatment being dependent upon the presence or absence of other complicating behavioral factors. Although patients are treated as inpatients, parents are encouraged to visit the children regularly, and are also encouraged to take the children home on weekends. Although outpatient treatment is possible if inpatient treatment cannot be arranged, it is, in our experience, at best a poor second choice and is contraindicated for at least two reasons. First, operant conditioning is highly dependent upon environmental control of reinforcement contingencies, and this can be much more adequately arranged for inpatients. Second, it has been our experience that nonverbal children develop a variety of ways of controlling their parents without the use of language. Until this pattern of behavior is eliminated the child will usually not develop functional speech. The most direct and effective way to break this pattern is through inpatient treatment. The treatment process is highly complex and time consuming and requires therapists who are familiar with and skilled in the administration of all the basic operant procedures for the control of behavior, such as shaping, fading, prompting, positive and negative reinforcement, time-out procedures, stimulus control, and schedule effects, as well as procedures for data recording and analysis. Each treatment session consists of a one-to-one relationship between therapist and patient. The treatment itself consists of tedious shaping of desired speech patterns in a laborious step-by-step fashion. In the initial stages of treatment the child is reinforced for making any random sound. As the rate of random vocalization increases the therapist imitates the child's sounds. The child is then reinforced if he repeats the therapist's sound. Grad-
................................----------------------------------------------237
OPERANT CONDITIONING OF SPEECH AND LANGUAGE
Table 1. Outline of Expressive Speech Development Curriculum APPROXIMATE EXPRESSIVE
VERBAL
LANGUAGE AGE
6 yrs or 72 mos 5 yrs or 60 mos
4 yrs or 48 mos
42 mos
3 yrs or 36 mos
30 mos
2 yrs or 24 mos
EXPRESSIVE SPEECH
LEVEL
Complex Verbal Behavior
24
Verbal Definition of 20 words Visual Stimulus + Naming Response (ten 8 to 10 word sentences) Verbal Stimulus + Imitative Response (ten 8 to 10 word sentences) Visual Stimulus + Naming Response (uses 1000 words) (ten 6 word sentences)
23 22
Verbal Stimulus + Imitative Response (ten 6 word sentences)
19
Visual Stimulus + Naming Response (ten 5 word sentences)
18
Verbal Stimulus + Imitative Response (ten 5 word sentences)
17
Visual Stimulus + Naming Response (uses 600 words) (ten 4 word sentences)
16
Verbal Stimulus + Imitative Response (ten 4 word sentences)
15
Visual Stimulus + Naming Response (ten 3 word sentences)
14
Verbal Stimulus + Imitative Response (ten 3 word sentences)
13
Visual Stimulus + Naming Response (uses 200 words) (ten 2 word phrases)
12
+ Imitative Response
11
Verbal Stimulus
21 20
(ten 2 word phrases) 20 mos
Visual Stimulus
+ Naming Response
10
(40 pictures) 18 mos
Visual Stimulus
+ Naming Response
9
(20 objects) 14 mos
Verbal Stimulus + Imitative Response (20 words)
8
1 yr or 12 mos
Vocal Stimulus + Imitative Response (12 sounds)
7
Experimenter Imitates Child's Sounds - Child Repeats Sounds
6
6 mos
Vocal Stimulus + Any Vocal Response (6 sounds)
5
5 mos
Differential Reinforcement of Specific Sounds Reinforcement of Any Vocal Response (Babbling)
4
Eye Contact in Response to Vocal Prompt
2
10 mos
4 mos
3
(Motor Imitation: May be Omitted) "'The language age equivalents are extrapolated from the norms given in the Pediatrician's Handbook of Communication Disorders;· the Bayley Manual; and the Binet Manual,"
238
PHILIP
W.
DRASH AND
J.
MICHAEL LEIBOWITZ
ually over a period of days or weeks the therapist assumes the lead role and determines which sounds shall be presented to the child. Correct sounds are immediately reinforced and errors are put on extinction. As the child's imitative repertoire of basic sounds increases to between 15 and 20 sounds, the therapist begins to use the sounds to chain and shape simple words. When the child's imitative vocabulary has increased to approximately 20 words the therapist transfers stimulus control to environmental objects. As soon as the child is reliably naming 20 objects, he is advanced to naming pictures and his vocabulary is rapidly expanded to include about 100 single words. The therapist then begins to teach the child at the next level of the curriculum and reinforces him for use of simple two-word phrases. This process, with technical variations, is continued until the child is using functional sentences of 6 to 10 words in length and is using his speech to communicate his needs in the environment. Simultaneously with the acquisition of these expressive skills, the child is being trained in a variety of receptive speech skills.
RESULTS OF TREATMENT For those children who respond to the program the results are highly consistent and the acceleration in the rate of speech and language development is quite rapid. In order to acquaint the pediatrician with the results which might be anticipated from such a treatment program, the results obtained with 9 recent patients are presented in Table 2 and Figure 1. As indicated in Table 2, the average age of the patients at initiation of treatment was 4.0 years. The mean IQ was 52.9 while the average expressive language age equivalent was 17.8 months. The average duration of treatment was 11.8 months. During the treatment period the average number of months of language age gained per treatment month was 2.5 months, or approximately 21/2 times the rate of speech acquisition of the normal child. When the rate of acquisition during therapy is compared to the rate prior to therapy it can be seen that most children accelerated four to eight times the rate prior to therapy. Figure 1 clearly illustrates several major points. First, the rate of acquisition of speech during therapy is highly consistent from child to child. Second, the rate of acquisition is fairly constant, regardless of the initial age of the child. Thus the earlier therapy is begun, the greater the probability that the child's language will approach normal at the end of treatment, since the absolute initial deficiency in terms of language age is less. This is well illustrated by comparing patient number 1 with patient number 5, both of whom were in treatment for about the same number of months. Although patient 1 and patient 5 gained approximately the same number of months during treatment, patient number 1 was much closer to normal level at termination of treatment than was patient number 5, because of 5's greater initial deficit. While the prognosis is certainly much better for children 3 years and
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Table 2.
Gains in Expressive Speech and Language By Nine Patients During Operant Conditioning EXPRESSIVE LANGUAGE AGE EQUIVALENT IN MONTHS
RATE OF SPEECH ACQUISITION COMPARED TO NORMAL
IN TREATMENT
IQ
Initial
Final
Gain
Rate Prior to Treatment
13 4
69 55
6 14
36 30
30 16
.27 .48
INITIAL SUBJECT
CHRONOLOGICAL AGE
MONTHS
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oz
Z <;)
o OJ r:n
Rate During Treatment 2.3 4.0
I:l
1.9
t""
2.7 2.0
q
'd
i"l i"l
n
1. S.E. 2. R.A.
1.8 2.4
~
3. K.M.
2.9
15
45
4. R.B. 5. D.S.
3.5 3.6
9 14
68 53
6. A.R.
3.8 4.8
15
24
5.6
25 5
67 55
8.0 4.0
6 11.8
40 52.9
7. E.W. 8. P.M. 9. T.E. Mean:
Mean number of months of language age gained per treatment month,
14 12
42
28
36 40
24 28
12 30
60 72
48 42
.27 .53
30 30
48 60
18 30
.45
1.7 3.6
.31
5.0
17.8
47.1
29.3
12
.40 .29 .28
3.2
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AVERAGE ".,.."
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4VRS 20
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50% AVERAGE
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MICHAEL LEIBOWITZ
75% AVERAGE
6YRS 24
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DRASH AND
16
25% AVERAGE
" 2
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12
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Figure 1. language.
AGE
IN
YEARS
Language acquisition of 9 patients during operant conditioning of speech and
younger, older children should not be automatically excluded as possible candidates for treatment, as is indicated by patient number 7, who was 4 years 9 months of age at initiation of treatment. This patient demonstrated almost total habilitation, but as indicated by Table 2, the patient's initial deficiency was not as severe as that of most of the other patients, and the treatment program extended for 25 months rather than 12. The decision regarding treatment of older children would thus entail consideration of (1) the initial language deficiency of the child, (2) the time available for treatment, and (3) the goals of treatment, i.e., total habilitation as opposed to acquisition of some functional speech. Figure 1 can also be used to predict the probable level of achievement of a patient after a specific period of treatment. For example, if one uses a multiple of twice the normal rate of language acquisition, a child entering the program with a chronological age of 2 years and a language age of 1 year should be near the normal level of speech development after 1 year of treatment, since he would increase by 2 years of language development while increasing 1 year in chronological age.
EFFECTS OF TREATMENT ON GENERAL COGNITIVE DEVELOPMENT Because of the intimate relationship between speech, language, and intelligence, it is inevitable that rapid acceleration in speech and lan-
OPERANT CONDITIONING OF SPEECH AND LANGUAGE
241
guage will have a beneficial effect upon the general cognitive development of the child. In the present group of patients, at least 2 (Sl and S6) are now functioning essentially as normal children, while 3 others are in normal school or preschool programs. Other investigators have obtained similar results in programs which placed stress on intensive and systematic sensory and language stimulation of young children. In a recent study Heber17 selected 40 infants born to retarded mothers with IQ's less than 70. Twenty infants were randomly assigned to an experimental treatment group and 20 to a control group. Intensive programming of the experimental group began during the first few weeks of life and continued through 42 months of age. When evaluated at age 31/2, the experimental group had a mean IQ of 127 while the control group had a mean IQ of 94; the discrepancy between the experimental over the control group was 33 IQ points. Gains of a similar magnitude were obtained in a study by Englemann l l who conducted an intensive 2 year training program with 4 year old disadvantaged children. At initiation of the program, the experimental group had a mean Binet30 IQ of 95.33 and the control group a mean of 94.50. At the end of 1 year in the program the mean IQ of the 15 children in the experimental group was 112.47 and the mean IQ of the 15 children in the control group was 102.57. After completion of the second year in the program the experimental group had a mean IQ of 121.08 and the control group a mean IQ of 99.61. The experimental group increased 25.75 IQ points during the program and the control group increased 5.11 IQ points. The experimental group exceeded the control group by 21.47 IQ points. It is thus apparent that treatment programs which stress the systematic programming of specific skills and behaviors required of the normal child at any given chronological age can have a major impact upon the cognitive and intellectual growth of below average and retarded children. The limits of such programming with the severely retarded child have yet to be determined. While it may be premature to agree with Staats28 that " ... children inherit, as members of the human species, a biological structure that fits them for the most complex intellectual learning and accomplishment," it is nevertheless clear that in many cases systematic operant treatment programs may produce significant improvements in the overall cognitive and behavioral repertoires of severely retarded children.
SUMMARY Severe speech and language retardation in young children ages 12 to 36 months, if untreated, may later result in an essentially nonremedial form of mental retardation. There is now available to the pediatrician a specific form of behavior modification therapy, the operant conditioning of speech and language, which is effective in accelerating the rate of speech and language development of selected groups of verbally deficient retarded children. Those children who have proven most responsive to this form of operant therapy are children without major neurological
242
PHILIP
W.
DRASH AND
J.
MICHAEL LEIBOWITZ
handicaps whose speech and language development lags behind their motor development. Data presently available suggest that referral for treatment at a very early age, prior to 2 or 3 years if possible, yields the most effective results. Such treatment, when combined with systematic programming of cognitive skills, may also have beneficial effects upon the overall intellectual development of the child. The pediatrician, as the professional having the most direct contact with the family in the early years of the child's life, plays a crucial role in the initiation of treatment. ACKNOWLEDGMENT
The authors express their appreciation to the staff and students of the Division of Psychology of The John F. Kennedy Institute who assisted in conducting this work and especially to Mr. Richard Baer whose therapeutic services have been invaluable.
REFERENCES 1. Bakwin, H.: Delayed speech: developmental mutism. Pediat. Clin. N. Amer., 15:627, 1968. 2. Bayley, N.: Manual for the Bayley Scales of Infant Development. New York, New York, The Psychological Corporation, 1969. 3. Bijou, S. W.: Behavior modification in the mentally retarded, application of operant conditioning principles. Pediat. Clin. N. Amer., 15:969, 1968. 4. Browning, R M., and Stover, D. 0.: Behavior Modification in Child Treatment: An Experimental and Clinical Approach. New York, New York, Aldine-Atherton, Inc., 1971. 5. Buddenhagen, R G.: Establishing Vocal Verbalizations in Mute Mongoloid Children. Champaign, Illinois, Research Press, 1971. 6. Cattell, P.: The Measurement of Intelligence of Infants and Young Children. New York, New York, The Psychological Corporation, 1960. 7. Drash, P. W.: A three-phase behavior modification program for language conditioning in autistic and nonverbal children. Proceedings of The Thirty-Ninth Annual Meeting of the Eastern Psychological Association, 1968. 8. Drash, P. W.: Habilitation of the retarded child: A remedial program. J. Spec. Educ. (in press). 9. Drash, P. W., Caldwell, L. R, and Leibowitz, J. M.: Correct and incorrect response rates as basic dependent variables in the operant conditioning of speech in nonverbal subjects. PsychoL Aspects Disab., 17:16, 1970. 10. Drash, P. W., and Leibowitz, J. M.: Building speech in autistic and nonverbal children. Proceedings of The Annual Meeting of the Maryland Psychological Association. Baltimore, Maryland, 1968. 11. Englemann, S.: The effectiveness of direct verbal instruction on IQ performance and achievement in reading and arithmetic. In Becker, W. C., ed.: An Empirical Basis for Change in Education: Selections on Behavioral Psychology for Teachers. Chicago, Illinois, Science Research Associates, 1971. 12. Gardner, W. I.: Behavior Modification in Mental Retardation: The Education and Rehabilitation of the Mentally Retarded Adolescent and Adult. New York, New York, AldineAtherton, 1971. 13. Gesell, A., and Amatruda, C. S.: Developmental Diagnosis: Normal and Abnormal Child Development, Clinical Methods and Pediatric Applications. New York, New York, Paul B. Hoeber, 1947. 14. Girardeau, F. L.: Cultural-familial retardation. In Ellis, N. R, ed.: International Review of Research in Mental Retardation, New York, New York, Academic Press, 1971, VoL 5. 15. Girardeau, F. L., and Spradlin, J. E., eds.: A functional analysis approach to speech and language. ASHA Monograph, No. 14, 1970. 16. Graziano, A. M., ed.: Behavior Therapy with Children. New York, New York, Aldine-Atherton, 1971. 17. Heber, R, and Garber, H.: An experiment in the prevention of cultural-familial mental retardation. Proceedings of the Second Congress of the International Association for the Scientific Study of Mental Deficiency, 1970. 18. Holden, R H.: Prediction of mental retardation in infancy. Ment. Retard., 10:28, 1972.
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19. Kerr, N., Meyerson, L., and Michael, J.: A procedure for shaping vocalizations in a mute child. In Ullmann, L. P., and Krasner, L., eds.: Case Studies in Behavior Modification. New York, New York, Holt, Rinehart and Winston, 1966. 20. Lillywhite, H. S., Young, N. B., and Olmsted, R W.: Pediatrician's Handbook of Communication Disorders. Philadelphia, Pennsylvania, Lea & Febiger, 1970. 21. Lovaas, O. I.: A program for the establishment of speech in psychotic children. In Wing, J. K., ed.: Childhood Autism. Oxford, England, Pergamon Press, 1966. 22. Neuringer, C., and Michael, J. L., eds.: Behavior Modification in Clinical Psychology. New York, New York, Appleton-Century-Crofts, 1970. 23. Pitts, C. E., ed.: Operant Conditioning in the Classroom: Introductory Readings in Educational Psychology. New York, New York, Thomas Y. Crowell, 1971. 24. Risley, T. R: The establishment of verbal behavior in deviant children. Unpublished dissertation. University of Washington, 1966. 25. Risley, T. R, and Wolf, M.: Establishing functional speech in echolalic children. Behav. Res. Ther., 5:73, 1967. 26. Sloane, H. N., Jr., and MacAulay, B. D., eds.: Operant Procedures in Remedial Speech and Language Training. Boston, Massachusetts, Houghton Mifflin Company, 1968. 27. Spradlin, J. E., and Girardeau, F. L.: The behavior of moderately and severely retarded persons. In Ellis, N. R, ed.: International Review of Research in Mental Retardation. New York, New York, Academic Press, 1966, VoL 1. 28. Staats, A. W.: Intelligence, biology or learning? Competing conceptions with social consequences. In Haywood, H. C., ed.: Social-cultural Aspects of Mental Retardation. New York, New York, Appleton-Century-Crofts, 1970. 29. Stedman, D. J.: The application of learning principles in pediatric practice. Pediat. Clin. N. Amer., 17:427, 1970. 30. Terman, L. M., and Merrill, M. A.: Stanford-Binet Intelligence Scale, Manual for the Third Revision, Form L-M. Boston, Massachusetts, Houghton Mifflin Co., 1960. 31. Weisburg, P.: Operant procedures with the retardate: An overview of laboratory research. In Ellis, N. R, ed.: International Review of Research in Mental Retardation. New York, New York, Academic Press, 1971, VoL 5. 32. Wolf, M. M., Risley, T. R, and Mees, H. I.: Application of operant conditioning procedures to the behavior problems of an autistic child. Behav. Res. Ther., 1 :305, 1964. 33. Yates, A. J.: Behavior Therapy. New York, New York, John Wiley and Sons, 1970. The John F. Kennedy Institute 707 North Broadway Baltimore, Maryland 21205
Operant Conditioning of Speech and Language in the Nonverbal Retarded Child Recent Advances
Philip W. Drash, Ph.D., * and J. Michael Leibowitz, M.A. **
Within recent years the science and associated technology of behavior modification and control in humans has shown rapid growth and development. Operant procedures are now routinely and successfully used in the treatment of a wide variety of behavior disorders by pediatricians, psychiatrists, psychologists, educators, nurses, social workers, and others. Operant procedures have proven especially beneficial in the remediation of routine behavioral disorders and deficiencies in the retarded child and are now employed as integral parts of the treatment program in many clinics, hospitals, and residential settings. One of the more significant recent developments within the field of behavior modification has been the development of systematic procedures for the operant conditioning of speech and language in nonverbal and verbally deficient children. Many pediatricians, speech pathologists, psychologists, psychiatrists, and others have recognized the significance of marked speech and language delay in the young child during the first 3 years of life. Until very recently, however, there was available to the pediatrician no systematic treatment program for habilitation of such children. Because of the lack of effective treatment techniques, pediatricians have in the past frequently adopted a "wait-and-see" attitude, hoping that the child with marked speech and language delay at about 2 years might spontaneously develop speech by 3 or 4 years. While an occasional child may acquire normal language as late as 4 years, such a case is, unfortunately, the exception. More commonly the child who shows marked "Director, Psychological Services, The John F. Kennedy Institute; Assistant Professor of Medical Psychology and Pediatrics, The Johns Hopkins University School of Medicine **Associate Director, Psychological Services, The John F. Kennedy Institute; Instructor in Pediatrics, The Johns Hopkins University School of Medicine Supported in part through Project 917, Maternal and Child Health Services, U.S. Department of Health, Education and Welfare.
Pediatric Clinics of North America- Vol. 20, No.1, February 1973
233
234
PHILIP
W.
DRASH AND
J.
MICHAEL LEIBOWITZ
,
speech and language deficiency at 2 to 3 years will continue to show mild to severe developmental retardation without treatment,! In this article we will familiarize the pediatrician with recent developments in behavior modification which make available to him, for the first time, operant treatment programs for habilitation of the young verbally deficient child, and will acquaint the pediatrician with the extremely important role he plays in the early identification and referral of verbally deficient children.
IDENTIFICATION, SCREENING, AND REFERRAL OF THE CHILD Much has been written from the medical standpoint regarding identification of the high risk child. This section is concerned not with neurological or physiological signs but with behavioral indices which afford the pediatrician clues to assist him in identification of the child with potential developmental disability who may benefit from remedial programs of speech and language conditioning. Many pediatricians are trained in the rudiments of intelligence testing and are familiar with the Gesell Developmental Norms,t3 the Cattell Infant Intelligence Scale,6 and The Bayley Scales of Infant Development." Norms are also available in handbooks such as the Pediatrician's Handbook of Communication Disorders. 20 If the pediatrician has reason to suspect that a child is significantly delayed in language development even as early as 1 year, he should compare the child's language development with several normative tables of language development. A recent study of 2875 infants over a 4 year period revealed that children developmentally delayed 1 month or more at age 8 months had significantly lower IQ scores at ages 4 and 7 years than a control group.1S It is thus clear that even moderate delays in speech development require careful attention by the pediatrician. Once a developmental delay is suspected or established and no clearly defined or severe neurological disease is present, early referral to a psychologist trained in behavior modification procedures may be indicated. While the pediatrician may feel some hesitancy about referring a 1112 to 2 year old child for evaluation, if the results are negative both the pediatrician and the child's parents are relieved of unnecessary worry. Conversely if treatment is indicated, early referral, in our experience, has proven most satisfactory for a number of reasons. First, the child's behavioral deficit is usually smaller at an early age and this increases the probability of therapeutic success. Generally, the more severe the problem, the longer treatment must be administered and the less likely that full remediation will be accomplished. Second, because there is frequently a long delay between referral and professional treatment, very early referral is almost a sine qua non if the treatment program is to be started before 2 or 3 years of age. Third, since the required behaviors a child should engage in increase at a slower rate in the early years, the total accumulated deficit to be overcome will be smaller even if there is a delay
OPERANT CONDITIONING OF SPEECH AND LANGUAGE
235
between referral and treatment. Fourth, early referral decreases the chances that new unacceptable behaviors will be learned which may possibly compete with the learning of speech. It is thus clear that the pediatrician, who is frequently the only health professional in contact with the parents of the young child during the first two or three years of the child's life, plays a crucial role in the initiation of treatment.
BEHAVIORAL EVALUATION OF LANGUAGE DEVELOPMENT Once a referral is made to a behaviorally oriented psychologist, the pediatrician may expect an assessment that includes both a standardized individual intelligence test, such as the Cattell Infant Intelligence Test6 or the Bayley Scales of Infant Development,2 and a diagnostic conditioning evaluation of speech and language. The individual intelligence test will provide the pediatrician with information regarding the child's generallevel of intellectual functioning as compared with other children his age, and may provide some specific information regarding the child's relative strengths and weaknesses. Diagnostic speech conditioning provides an objective index of the child's expressive and receptive language repertoires and also determines what types of environmental stimuli control a child's verbal behavior. The diagnostic conditioning evaluation consists of four parts and allows the psychologist to predict the child's probable rate of progress in an operant treatment program. Included in the diagnostic conditioning evaluation are: (1) A determination of the initial level of the child's expressive language behavior, which is used as a baseline from which therapeutic change is measured; (2) A determination of possible reinforcing consequences, based upon systematic attempts to control the patient's behavior using a variety of reinforcers; (3) Determination of the child's probable progress in the program by attempting to teach new behaviors which did not appear during baseline testing; (4) Assessment of the presence or absence of behavioral problems which might compete with rapid therapeutic change. In some cases the behavioral evaluation may indicate that the child does not require operant speech conditioning but may identify other behavior problems which warrant immediate attention, such as extreme negativistic behavior. Behavior problems are assessed following the same general procedures as above. Techniques for the elimination of the behavior are identified and probable maintaining consequences are determined. An outline of the therapeutic program for the child may then be developed. The results of such behavioral evaluations provide the pediatrician with at least three types of information. The evaluation provides an estimate of the probable therapeutic time needed to modify the behavior in question, it determines if referral to other specialists will be necessary, and it provides the pediatrician with specific therapeutic suggestions for working with the families of those children who do not require intensive operant therapy.
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MICHAEL LEIBOWITZ
THE TREATMENT PROGRAM For those patients who require intensive treatment, the Kennedy program may serve as a model. The operant treatment program for nonverbal children, developed primarily by the senior author with the collaboration of the junior author and other departmental associates, consists of a highly structured expressive language development curriculum containing a series of discrete steps which parallel the development of speech and language in the normal child between birth and approximately 5 to 6 years. An outline of the speech and language C'llrriculum is presented in Table 1. The approximate expressive language age equivalent for the various levels is indicated in the first column. The language age equivalents are extrapolated from the norms of the Binet,30 the Bayley,2 and the Pediatrician's Handbook of Communication Disorders.20 As indicated in Table 1, the program consists of 24 discrete steps which the child must progress through. Each step has a clearly defined criterion level which must be met before the child moves to the next level of the curriculum. This procedure insures that the child has mastered all skills below the specific level on which he may be working. Children are typically treated as inpatients and receive two 1 hour periods of therapy per day by therapists trained in the operant conditioning of speech and language. The typical treatment program extends for a period of 6 to 12 months, the duration of treatment being dependent upon the presence or absence of other complicating behavioral factors. Although patients are treated as inpatients, parents are encouraged to visit the children regularly, and are also encouraged to take the children home on weekends. Although outpatient treatment is possible if inpatient treatment cannot be arranged, it is, in our experience, at best a poor second choice and is contraindicated for at least two reasons. First, operant conditioning is highly dependent upon environmental control of reinforcement contingencies, and this can be much more adequately arranged for inpatients. Second, it has been our experience that nonverbal children develop a variety of ways of controlling their parents without the use of language. Until this pattern of behavior is eliminated the child will usually not develop functional speech. The most direct and effective way to break this pattern is through inpatient treatment. The treatment process is highly complex and time consuming and requires therapists who are familiar with and skilled in the administration of all the basic operant procedures for the control of behavior, such as shaping, fading, prompting, positive and negative reinforcement, time-out procedures, stimulus control, and schedule effects, as well as procedures for data recording and analysis. Each treatment session consists of a one-to-one relationship between therapist and patient. The treatment itself consists of tedious shaping of desired speech patterns in a laborious step-by-step fashion. In the initial stages of treatment the child is reinforced for making any random sound. As the rate of random vocalization increases the therapist imitates the child's sounds. The child is then reinforced if he repeats the therapist's sound. Grad-
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OPERANT CONDITIONING OF SPEECH AND LANGUAGE
Table 1. Outline of Expressive Speech Development Curriculum APPROXIMATE EXPRESSIVE
VERBAL
LANGUAGE AGE
6 yrs or 72 mos 5 yrs or 60 mos
4 yrs or 48 mos
42 mos
3 yrs or 36 mos
30 mos
2 yrs or 24 mos
EXPRESSIVE SPEECH
LEVEL
Complex Verbal Behavior
24
Verbal Definition of 20 words Visual Stimulus + Naming Response (ten 8 to 10 word sentences) Verbal Stimulus + Imitative Response (ten 8 to 10 word sentences) Visual Stimulus + Naming Response (uses 1000 words) (ten 6 word sentences)
23 22
Verbal Stimulus + Imitative Response (ten 6 word sentences)
19
Visual Stimulus + Naming Response (ten 5 word sentences)
18
Verbal Stimulus + Imitative Response (ten 5 word sentences)
17
Visual Stimulus + Naming Response (uses 600 words) (ten 4 word sentences)
16
Verbal Stimulus + Imitative Response (ten 4 word sentences)
15
Visual Stimulus + Naming Response (ten 3 word sentences)
14
Verbal Stimulus + Imitative Response (ten 3 word sentences)
13
Visual Stimulus + Naming Response (uses 200 words) (ten 2 word phrases)
12
+ Imitative Response
11
Verbal Stimulus
21 20
(ten 2 word phrases) 20 mos
Visual Stimulus
+ Naming Response
10
(40 pictures) 18 mos
Visual Stimulus
+ Naming Response
9
(20 objects) 14 mos
Verbal Stimulus + Imitative Response (20 words)
8
1 yr or 12 mos
Vocal Stimulus + Imitative Response (12 sounds)
7
Experimenter Imitates Child's Sounds - Child Repeats Sounds
6
6 mos
Vocal Stimulus + Any Vocal Response (6 sounds)
5
5 mos
Differential Reinforcement of Specific Sounds Reinforcement of Any Vocal Response (Babbling)
4
Eye Contact in Response to Vocal Prompt
2
10 mos
4 mos
3
(Motor Imitation: May be Omitted) "'The language age equivalents are extrapolated from the norms given in the Pediatrician's Handbook of Communication Disorders;· the Bayley Manual; and the Binet Manual,"
238
PHILIP
W.
DRASH AND
J.
MICHAEL LEIBOWITZ
ually over a period of days or weeks the therapist assumes the lead role and determines which sounds shall be presented to the child. Correct sounds are immediately reinforced and errors are put on extinction. As the child's imitative repertoire of basic sounds increases to between 15 and 20 sounds, the therapist begins to use the sounds to chain and shape simple words. When the child's imitative vocabulary has increased to approximately 20 words the therapist transfers stimulus control to environmental objects. As soon as the child is reliably naming 20 objects, he is advanced to naming pictures and his vocabulary is rapidly expanded to include about 100 single words. The therapist then begins to teach the child at the next level of the curriculum and reinforces him for use of simple two-word phrases. This process, with technical variations, is continued until the child is using functional sentences of 6 to 10 words in length and is using his speech to communicate his needs in the environment. Simultaneously with the acquisition of these expressive skills, the child is being trained in a variety of receptive speech skills.
RESULTS OF TREATMENT For those children who respond to the program the results are highly consistent and the acceleration in the rate of speech and language development is quite rapid. In order to acquaint the pediatrician with the results which might be anticipated from such a treatment program, the results obtained with 9 recent patients are presented in Table 2 and Figure 1. As indicated in Table 2, the average age of the patients at initiation of treatment was 4.0 years. The mean IQ was 52.9 while the average expressive language age equivalent was 17.8 months. The average duration of treatment was 11.8 months. During the treatment period the average number of months of language age gained per treatment month was 2.5 months, or approximately 21/2 times the rate of speech acquisition of the normal child. When the rate of acquisition during therapy is compared to the rate prior to therapy it can be seen that most children accelerated four to eight times the rate prior to therapy. Figure 1 clearly illustrates several major points. First, the rate of acquisition of speech during therapy is highly consistent from child to child. Second, the rate of acquisition is fairly constant, regardless of the initial age of the child. Thus the earlier therapy is begun, the greater the probability that the child's language will approach normal at the end of treatment, since the absolute initial deficiency in terms of language age is less. This is well illustrated by comparing patient number 1 with patient number 5, both of whom were in treatment for about the same number of months. Although patient 1 and patient 5 gained approximately the same number of months during treatment, patient number 1 was much closer to normal level at termination of treatment than was patient number 5, because of 5's greater initial deficit. While the prognosis is certainly much better for children 3 years and
o'd i"l
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Table 2.
Gains in Expressive Speech and Language By Nine Patients During Operant Conditioning EXPRESSIVE LANGUAGE AGE EQUIVALENT IN MONTHS
RATE OF SPEECH ACQUISITION COMPARED TO NORMAL
IN TREATMENT
IQ
Initial
Final
Gain
Rate Prior to Treatment
13 4
69 55
6 14
36 30
30 16
.27 .48
INITIAL SUBJECT
CHRONOLOGICAL AGE
MONTHS
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o OJ r:n
Rate During Treatment 2.3 4.0
I:l
1.9
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2.7 2.0
q
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1. S.E. 2. R.A.
1.8 2.4
~
3. K.M.
2.9
15
45
4. R.B. 5. D.S.
3.5 3.6
9 14
68 53
6. A.R.
3.8 4.8
15
24
5.6
25 5
67 55
8.0 4.0
6 11.8
40 52.9
7. E.W. 8. P.M. 9. T.E. Mean:
Mean number of months of language age gained per treatment month,
14 12
42
28
36 40
24 28
12 30
60 72
48 42
.27 .53
30 30
48 60
18 30
.45
1.7 3.6
.31
5.0
17.8
47.1
29.3
12
.40 .29 .28
3.2
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N)
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240
PHILIP
W.
AVERAGE ".,.."
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4VRS 20
3vIS
50% AVERAGE
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MICHAEL LEIBOWITZ
75% AVERAGE
6YRS 24
z
J.
DRASH AND
16
25% AVERAGE
" 2
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12
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7
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5
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I. CHRONOLOGICAL
Figure 1. language.
AGE
IN
YEARS
Language acquisition of 9 patients during operant conditioning of speech and
younger, older children should not be automatically excluded as possible candidates for treatment, as is indicated by patient number 7, who was 4 years 9 months of age at initiation of treatment. This patient demonstrated almost total habilitation, but as indicated by Table 2, the patient's initial deficiency was not as severe as that of most of the other patients, and the treatment program extended for 25 months rather than 12. The decision regarding treatment of older children would thus entail consideration of (1) the initial language deficiency of the child, (2) the time available for treatment, and (3) the goals of treatment, i.e., total habilitation as opposed to acquisition of some functional speech. Figure 1 can also be used to predict the probable level of achievement of a patient after a specific period of treatment. For example, if one uses a multiple of twice the normal rate of language acquisition, a child entering the program with a chronological age of 2 years and a language age of 1 year should be near the normal level of speech development after 1 year of treatment, since he would increase by 2 years of language development while increasing 1 year in chronological age.
EFFECTS OF TREATMENT ON GENERAL COGNITIVE DEVELOPMENT Because of the intimate relationship between speech, language, and intelligence, it is inevitable that rapid acceleration in speech and lan-
OPERANT CONDITIONING OF SPEECH AND LANGUAGE
241
guage will have a beneficial effect upon the general cognitive development of the child. In the present group of patients, at least 2 (Sl and S6) are now functioning essentially as normal children, while 3 others are in normal school or preschool programs. Other investigators have obtained similar results in programs which placed stress on intensive and systematic sensory and language stimulation of young children. In a recent study Heber17 selected 40 infants born to retarded mothers with IQ's less than 70. Twenty infants were randomly assigned to an experimental treatment group and 20 to a control group. Intensive programming of the experimental group began during the first few weeks of life and continued through 42 months of age. When evaluated at age 31/2, the experimental group had a mean IQ of 127 while the control group had a mean IQ of 94; the discrepancy between the experimental over the control group was 33 IQ points. Gains of a similar magnitude were obtained in a study by Englemann l l who conducted an intensive 2 year training program with 4 year old disadvantaged children. At initiation of the program, the experimental group had a mean Binet30 IQ of 95.33 and the control group a mean of 94.50. At the end of 1 year in the program the mean IQ of the 15 children in the experimental group was 112.47 and the mean IQ of the 15 children in the control group was 102.57. After completion of the second year in the program the experimental group had a mean IQ of 121.08 and the control group a mean IQ of 99.61. The experimental group increased 25.75 IQ points during the program and the control group increased 5.11 IQ points. The experimental group exceeded the control group by 21.47 IQ points. It is thus apparent that treatment programs which stress the systematic programming of specific skills and behaviors required of the normal child at any given chronological age can have a major impact upon the cognitive and intellectual growth of below average and retarded children. The limits of such programming with the severely retarded child have yet to be determined. While it may be premature to agree with Staats28 that " ... children inherit, as members of the human species, a biological structure that fits them for the most complex intellectual learning and accomplishment," it is nevertheless clear that in many cases systematic operant treatment programs may produce significant improvements in the overall cognitive and behavioral repertoires of severely retarded children.
SUMMARY Severe speech and language retardation in young children ages 12 to 36 months, if untreated, may later result in an essentially nonremedial form of mental retardation. There is now available to the pediatrician a specific form of behavior modification therapy, the operant conditioning of speech and language, which is effective in accelerating the rate of speech and language development of selected groups of verbally deficient retarded children. Those children who have proven most responsive to this form of operant therapy are children without major neurological
242
PHILIP
W.
DRASH AND
J.
MICHAEL LEIBOWITZ
handicaps whose speech and language development lags behind their motor development. Data presently available suggest that referral for treatment at a very early age, prior to 2 or 3 years if possible, yields the most effective results. Such treatment, when combined with systematic programming of cognitive skills, may also have beneficial effects upon the overall intellectual development of the child. The pediatrician, as the professional having the most direct contact with the family in the early years of the child's life, plays a crucial role in the initiation of treatment. ACKNOWLEDGMENT
The authors express their appreciation to the staff and students of the Division of Psychology of The John F. Kennedy Institute who assisted in conducting this work and especially to Mr. Richard Baer whose therapeutic services have been invaluable.
REFERENCES 1. Bakwin, H.: Delayed speech: developmental mutism. Pediat. Clin. N. Amer., 15:627, 1968. 2. Bayley, N.: Manual for the Bayley Scales of Infant Development. New York, New York, The Psychological Corporation, 1969. 3. Bijou, S. W.: Behavior modification in the mentally retarded, application of operant conditioning principles. Pediat. Clin. N. Amer., 15:969, 1968. 4. Browning, R M., and Stover, D. 0.: Behavior Modification in Child Treatment: An Experimental and Clinical Approach. New York, New York, Aldine-Atherton, Inc., 1971. 5. Buddenhagen, R G.: Establishing Vocal Verbalizations in Mute Mongoloid Children. Champaign, Illinois, Research Press, 1971. 6. Cattell, P.: The Measurement of Intelligence of Infants and Young Children. New York, New York, The Psychological Corporation, 1960. 7. Drash, P. W.: A three-phase behavior modification program for language conditioning in autistic and nonverbal children. Proceedings of The Thirty-Ninth Annual Meeting of the Eastern Psychological Association, 1968. 8. Drash, P. W.: Habilitation of the retarded child: A remedial program. J. Spec. Educ. (in press). 9. Drash, P. W., Caldwell, L. R, and Leibowitz, J. M.: Correct and incorrect response rates as basic dependent variables in the operant conditioning of speech in nonverbal subjects. PsychoL Aspects Disab., 17:16, 1970. 10. Drash, P. W., and Leibowitz, J. M.: Building speech in autistic and nonverbal children. Proceedings of The Annual Meeting of the Maryland Psychological Association. Baltimore, Maryland, 1968. 11. Englemann, S.: The effectiveness of direct verbal instruction on IQ performance and achievement in reading and arithmetic. In Becker, W. C., ed.: An Empirical Basis for Change in Education: Selections on Behavioral Psychology for Teachers. Chicago, Illinois, Science Research Associates, 1971. 12. Gardner, W. I.: Behavior Modification in Mental Retardation: The Education and Rehabilitation of the Mentally Retarded Adolescent and Adult. New York, New York, AldineAtherton, 1971. 13. Gesell, A., and Amatruda, C. S.: Developmental Diagnosis: Normal and Abnormal Child Development, Clinical Methods and Pediatric Applications. New York, New York, Paul B. Hoeber, 1947. 14. Girardeau, F. L.: Cultural-familial retardation. In Ellis, N. R, ed.: International Review of Research in Mental Retardation, New York, New York, Academic Press, 1971, VoL 5. 15. Girardeau, F. L., and Spradlin, J. E., eds.: A functional analysis approach to speech and language. ASHA Monograph, No. 14, 1970. 16. Graziano, A. M., ed.: Behavior Therapy with Children. New York, New York, Aldine-Atherton, 1971. 17. Heber, R, and Garber, H.: An experiment in the prevention of cultural-familial mental retardation. Proceedings of the Second Congress of the International Association for the Scientific Study of Mental Deficiency, 1970. 18. Holden, R H.: Prediction of mental retardation in infancy. Ment. Retard., 10:28, 1972.
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19. Kerr, N., Meyerson, L., and Michael, J.: A procedure for shaping vocalizations in a mute child. In Ullmann, L. P., and Krasner, L., eds.: Case Studies in Behavior Modification. New York, New York, Holt, Rinehart and Winston, 1966. 20. Lillywhite, H. S., Young, N. B., and Olmsted, R W.: Pediatrician's Handbook of Communication Disorders. Philadelphia, Pennsylvania, Lea & Febiger, 1970. 21. Lovaas, O. I.: A program for the establishment of speech in psychotic children. In Wing, J. K., ed.: Childhood Autism. Oxford, England, Pergamon Press, 1966. 22. Neuringer, C., and Michael, J. L., eds.: Behavior Modification in Clinical Psychology. New York, New York, Appleton-Century-Crofts, 1970. 23. Pitts, C. E., ed.: Operant Conditioning in the Classroom: Introductory Readings in Educational Psychology. New York, New York, Thomas Y. Crowell, 1971. 24. Risley, T. R: The establishment of verbal behavior in deviant children. Unpublished dissertation. University of Washington, 1966. 25. Risley, T. R, and Wolf, M.: Establishing functional speech in echolalic children. Behav. Res. Ther., 5:73, 1967. 26. Sloane, H. N., Jr., and MacAulay, B. D., eds.: Operant Procedures in Remedial Speech and Language Training. Boston, Massachusetts, Houghton Mifflin Company, 1968. 27. Spradlin, J. E., and Girardeau, F. L.: The behavior of moderately and severely retarded persons. In Ellis, N. R, ed.: International Review of Research in Mental Retardation. New York, New York, Academic Press, 1966, VoL 1. 28. Staats, A. W.: Intelligence, biology or learning? Competing conceptions with social consequences. In Haywood, H. C., ed.: Social-cultural Aspects of Mental Retardation. New York, New York, Appleton-Century-Crofts, 1970. 29. Stedman, D. J.: The application of learning principles in pediatric practice. Pediat. Clin. N. Amer., 17:427, 1970. 30. Terman, L. M., and Merrill, M. A.: Stanford-Binet Intelligence Scale, Manual for the Third Revision, Form L-M. Boston, Massachusetts, Houghton Mifflin Co., 1960. 31. Weisburg, P.: Operant procedures with the retardate: An overview of laboratory research. In Ellis, N. R, ed.: International Review of Research in Mental Retardation. New York, New York, Academic Press, 1971, VoL 5. 32. Wolf, M. M., Risley, T. R, and Mees, H. I.: Application of operant conditioning procedures to the behavior problems of an autistic child. Behav. Res. Ther., 1 :305, 1964. 33. Yates, A. J.: Behavior Therapy. New York, New York, John Wiley and Sons, 1970. The John F. Kennedy Institute 707 North Broadway Baltimore, Maryland 21205