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The effects of punishing stuttering expectations and stuttering utterances: A comparative study
BEHAVIOR THERAPY (1970) 1, 228-239
The Effects of Punishing Stuttering Expectations and Stuttering Utterances: A Comparative Study 1 DAVID A. DALY 2
University of Alabama in Birmingham AND JAMES V . FRICK
Pennsylvania State University The effects of contingent shock,on signaled stuttering expectancies and/or stuttering utterances were studied in 36 adult male stutterers. Each subject participated in only one of three different punishment conditions. Each condition consisted of three segments: Base Rate, Training, and Recovery. Punishment was administered only during the Training segments. Electroshock was delivered contingent upon signaled expectancies to stutter in one condition; in a second condition, shock was administered for emitted stuttering utterances; and in the third condition, the effect of punishment for both signaled expectancies and stuttered utterances was studied. The general findings were: (a) significant differences existed among conditions with respect to both the frequency of signaled stuttering expectancies and the frequency of stuttering utterances; (b) punishment of signaled expectancies effected only a moderate reduction in additional stuttering expectancies; (c) stuttering utterance contingent shock effected a significant decrease in stuttering; and (d) the combined punishment procedure effected significant reductions in both signaled expectancies and stuttering utterances. A major finding was that the combined punishment procedure did not effect a more immediate or a more significant reduction in stuttering than the stuttering utterance contingent punishment procedure.
Several investigators who have employed electric shock as a form of punishment for stuttering have reported that the frequency of stuttering is markedly reduced in the laboratory when shock is administered contingent upon stuttered utterances. For example, Martin and Siegel (1966) found that response contingent electric shock was effective in decreasing stuttering, with the introduction of shock resulting in almost a total reducThis investigation was supported in part by United Cerebral Palsy Research and Educational Foundation Grant No. T-779-68, obtained through the American Speech and Hearing Foundation. This report was based on Daly's dissertation completed at the Pennsylvania State University in 1968 under the direction of Frick. Reprints may be obtained from David A. Daly, Ed. D., Center for Developmental and Learning Disorders, University of Alabama in Birmingham, 1919 Seventh Avenue South, Birmingham, Alabama 35233. 228
E F F E C T S OF P U N I S H M E N T
ON S T U T T E R I N G
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tion of stuttering for all three of their subjects. Daly and Cooper (1967) and Brady (1967) also found marked reductions in the frequency of stuttering during their stuttering contingent electroshock conditions. The results of a recent investigation by Curlee and Perl~ins (1968) indicated that punishment (electric shock) for signaled expectations of stuttering effected a significant decrease in both the frequency of stuttering utterances and further stuttering expectancies. Curlee and Perkins utilized three conditions, four subjects per condition. Each condition consisted of three segments: a baseline measurement period in which the frequency of signaled expectancies to stutter and instances of stuttering prior to punishment were counted; a training period in which the punishment was administered; and an extinction period to determine the effect of the punishment following conditioning. Single words were used as stimuli and the training periods varied as follows: Experimental group. Subjects were shocked immediately following their signaled stuttering expectancies; however, the shock was administered on a predetermined variable-ratio schedule. Interestingly, whenever a subject was shocked, he was not allowed to say the sentence he composed and therefore did not stutter on the stimulus word. Yoked-control group. Subjects were paired with, and received the same number of shocks per 50-word grouping as the subjects in the experimental group. However, the shock was not administered immediately following a signaled expectancy to stutter; rather, it was administered randomly at least 5 sec after a sentence had been said and 5 sec before the presentation of the next stimulus word. Time-control group. Subjects signaled their expectancies to stutter, and although they were "wired for shock," it was not administered. Curlee and Perkins' analyses were based upon the difference scores between the frequency of signaled stuttering expectancies obtained during the baseline and extinction periods and the difference scores between the frequency of stuttering utterances obtained during the same periods. They found that punishment of expectancy to stutter was associated with significant decreases in the frequencies of both expectancy and stuttering. Specifically, the decrease in their experimental or shock-contingent group was significantly greater than in either control group. The significant reductions in both stuttering expectancies and stuttering utterances which Curlee and Perkins found lead to several interesting questions. The major question we were interested in was: "Would punishing stutterers for both their signaled expectancies and their overt stuttering utterances result in a greater and a more immediate reduction
230
DALY AND FRICK
in the frequency of stuttering than the type of procedure in which stutteri n g e x p e c t a n c i e s or s t u t t e r i n g u t t e r a n c e s a l o n e a r e p u n i s h e d ? " A s e c ondary purpose of the present experiment was to determine if 100% punishment for signaled stuttering expectancies would result in similar reductions to Curlee and Perkins' findings using intermittent punishment. METHOD
Subjects Individuals who stuttered at least 5% of the time when reading 40 practice words were selected as subjects. A 5% criterion was used to insure that all subjects demonstrated stuttering behavior and to allow for possible reductions in stuttering expectancies and/or stuttering utterances which might have resulted from the different punishments administered. From a total of 49 stutterers, 36 male subjects reached the 5% criterion. Twelve of the 13 stutterers who were not selected as subjects did not stutter or expect to stutter on at least 5% of the practice words. The other stutterer who was not selected was a severe stutterer; however, he experienced difficulty reading the 40 practice words and was excluded because of his reading problem. The ages of the 36 subjects selected ranged from 17 to 42 years, with a mean age of 23 years. The number of months in speech therapy ranged from 1 month to 15 years, with the mean therapy time being 3.5 years.
Materials Fourteen words for each of the 20 initial consonant sounds found by Johnson and Brown (1935) to evoke the greatest amount of stuttering were selected from Thorndike and Lorge's (1944) text. Only words of two or more syllables were considered, and, to control for familiarity, words were chosen from Thorndike and Lorge's category "words occurring at least once per 1,000,000 words." From the total list of 280 words (14 for each of the 20 consonant sounds), 6 words were randomly selected from each consonant classification to constitute the Training words. Three words from each phoneme class were chosen for the Base Rate words, and three were randomly chosen for the Recovery words. The 40 remaining words were used as the reading stimuli in the practice session. A slide was made for each word and the stimuli were presented via a projector.
Instrumentation A commercially constructed punishing device (Electronic Stimulator, Model 751) was used to deliver the shock. This instrument had the capacity to deliver a shock with an intensity of 0.15 to 150 V. A metal box was built for the subjects to use to signal whether or not they expected to stutter when seeing each stimulus word. The box contained two buttons: a red button on the right surface of the box to be pushed when stuttering was expected, and a black button on the left surface of the box to be pushed when stuttering was not expected. The two signaling buttons were connected to an automatic counter (Easterline Angus graphic ammeter, Model AW) which provided a record of each subject's signaled expectancies and nonexpectancies to stutter.
EFFECTS OF PUNISHMENT ON STUTTERING
231
Procedure Each subject was seated at a table with the box positioned in front of him. The stimulus words were individually shown on a wall approximately 6 feet from the subject. A red light came on 3 sec after each word was exposed. This light indicated that the subject should signal whether or not he expected to stutter on the word when saying it aloud. Following each decision, a green light was turned on at intervals varying from 1, 2, 3, 4, or 5 sec. The green light was the signal for the subject to say the stimulus word. Each subject was randomly assigned to one of three different punishment conditions, so there were 12 subjects in each condition. Each condition consisted of three segments: Base Rate, Training, and Recovery. Base Rate. The Base Rate segment consisted of 60 stimulus words and provided a baseline measure of each subject's frequency of signaled stuttering expectancies and frequency of stuttering utterances prior to the administration of the punishment. Training. Following the Base Rate segment, two electrodes were attached to each subject and his threshold for pain was determined. The subjects' pain thresholds ranged from 50 to 140 V with the mean pain threshold being 96.25 V. The intensity of the shock received by each subject was 5 V above his pain threshold. During the 120 word Training segment electric shock was administered contingent upon the specified response or responses to be punished in the respective conditions. Subjects in Condition I were punished immediately following each signaled stuttering expectancy; subjects in Condition II were punished immediately following each stuttered word; and subjects in Condition III were punished immediately following both signaled expectancies to stutter and actual stuttering utterances. Recovery. When the subjects finished reading the 120 words in the Training segment, the electrodes were removed. However, the subjects continued to signal their anticipations of stuttering on an additional 60 words which constituted the Recovery segment. Shock or threat of shock was not a factor in this segment as there was no possibility of being punished.
Responses Each subject's signaled expectancies and nonexpectancies were recorded electronically with an automatic counter which was connected to the two signaling buttons. Stuttered words were recorded on a score sheet by the experimenter. His competence to determine stuttering utterances was obtained by comparing his judgment with two experienced professors in speech pathology. The interjudge reliability obtained was 96%. RESULTS The percentages of signaled stuttering expectancies and the percenta g e s o f s t u t t e r i n g u t t e r a n c e s a r e p r e s e n t e d in T a b l e 1 a n d T a b l e 2, r e s p e c t i v e l y . T h e 1 2 0 - w o r d T r a i n i n g p e r i o d w a s d i v i d e d i n t o t w o 6 0 - w o r d segm e n t s ( T r a i n i n g A a n d T r a i n i n g B) t o s h o w w h e t h e r t h e p u n i s h m e n t s employed had an immediate or a continuous effect. In order to answer the questions asked, the data were analyzed using two factorial designs with repeated measures on one of the factors (after W i n e r , 1962). T h e s e t w o a n a l y s e s w i l l b e d i s c u s s e d s e p a r a t e l y . I n b o t h a n a l y s e s t h e t h r e e d i f f e r e n t p u n i s h m e n t c o n d i t i o n s w e r e c o n s i d e r e d as
232
DALY AND FRICK TABLE 1 Mean Percentages of Signaled Stuttering Expectancies for the Four 60-Word Segments According to Conditionsa
Conditions
Base Rate
Training A
Trmning B
Recovery
I
47
42
38
42
II III
32 27
23 19
17 ll
13 16
a Twelve s u ~ e c t s i n each condition. TABLE 2 Mean Percentages of Stuttering Utterances for the Four 60-Word Segments According to Conditionsa Conditions
Base Rate
Trmning A
Training B
Recovery
I
47
45
42
42
II III
33 27
15 19
11 10
12 15
a Twelve subjects in each condition.
one factor, while the segments in each condition were considered as the other.
Analysis 1: Effect of Punishments on Signaled Stuttering Expectancies This factorial analysis tested whether the three punishment conditions differently affected the frequency of stuttering expectancies in each segment of the experiment. The results of this analysis, as shown in Table 3, revealed that there was a significant difference (p < .05) among the TABLE 3 Summary of Analysis of Variance for the Frequency of Signaled Stuttering Expectancies Under Three Punishment Conditions Source
df
Between subjects Conditions (A) Subjects within conditions Within subjects Segments (B) Conditions x Segments (AB) Segments x Subjects within conditions
35 2 33 180 5 10 165
a Significant at the .05 level. b Significant at the .01 level.
MS
1973.07 452.25 1340.00 72.80 24.12
F
4.3627 a
55.53 b 3.020
233
EFFECTS OF PUNISHMENT ON STUTTERING
frequencies of signaled expectancies in the three punishment conditions. Specific comparisons revealed that the frequencies of stuttering expectancies signaled during the Training segments of Conditions II and III were significantly lower (p < .01) than the frequency of expectancies signaled during the Training period in Condition I. This finding, however, was interpreted with caution because the 12 stutterers randomly assigned to Condition I were, by chance, more severe than the stutterers assigned to the other two conditions. Although differences obtained between the subjects in Condition II and Condition III were viewed with more confidence, these differences were not statistically significant. Thus, the results of this study indicate that combined punishment, as administered in Condition III, was not a more effective procedure for reducing stuttering expectancies than the punishment administered for stuttered utterances alone, Condition II. Figure 1 clearly shows that the subjects in all conditions reduced the frequency of their stuttering expectancies in their respective Training periods. The 120-word Training periods were divided into four 30-word segments to permit precise visual inspection of the changes which occurred throughout the punishment periods. The small increases in the frequency of signaled expectancies which occurred in the Recovery segments of Conditions I and III did not begin to approach the Base Rate level of responding. Thus, marked spontaneous recovery of expectancies to stutter was not found in this study. In fact, further reduction in the frequency of stuttering expectancies was noted in the Recovery period of Condition II. CONOITION I
IOO
CONDITION Tr .
~ 90
,, ,,
,
. . . . .
C ONOITION TIT~ , w ~ = -
~ 801
×"=~oi bJ 6C ._1 z,~ 5c ¢n 4 0
w 30, Z bJ
2o ~
w
I
I
BASE RATE Troiningl
I
I
I
I
Training2 Training3 Troining4 RECOVERY
FIG. 1. Mean percentages of signaled stuttering expectancies for Base Rate, Recovery, and the four 30-word within-Training groups for each condition.
234
DALY AND FRICK DISCUSSION
FOR ANALYSIS
1
The results obtained indicate that punishment for stuttering utterances (Condition II) and punishment for both signaled expectancies and stuttering utterances (Condition Ill) were more effective procedures for reducing the frequency of signaled expectancies than punishment for signaled stuttering expectancies alone (Condition I). These findings were considered with care because the higher percentage of signaled expectancies in Condition I was apparently the result of a greater proportion of severe stutterers in that condition. One purpose of the present study was to determine if 100% punishment for signaled stuttering expectancies would yield similar results to those obtained by Curlee and Perkins (1968) using intermittent punishment. In their comparison of three different conditions, they found that shock for signaled stuttering expectancies resulted in the greatest reduction of subsequent expectancies when compared to their two control conditions. The results of the present investigation do not agree with Curlee and Perkins' findings. Five possible explanations for the difference in findings are offered. First, the severe stutterers in Condition I of this study may possibly have masked any marked reduction which might have occurred if moderate or mild stutterers had comprised the group. One cannot tell from Curlee and Perkins' study whether the four subjects in their stuttering contingent punishment condition were severe, moderate, or mild stutterers. Second, the stimulus words used in the two studies differed in difficulty. Curlee and Perkins' selected words from the Throndike and Lorge (1944) list of most frequently used 1000 words. These words are common and, for the most part, only one syllable in length. The stimulus words chosen for the present study were less common (occurring only once per 1,000,000 words) and consisted of two or more syllables. The third explanation for Curlee and Perkins' greater reduction in expectancies may be that their Training segment was over three times as long as the Training segment of the present study. Specifically, Curlee and Perkins' Training period lasted until 400 stimulus words had been said or until 2 hr had passed, whichever occurred first, whereas the Training segment in this study lasted only as long as it took each subject to signal and utter the 120 stimulus words. The fourth reason offered to explain the difference in findings may be that the schedules of punishment were different for the two studies. Curlee and Perkins' subjects significantly reduced their signaled stuttering expectancies when intermittent shock was used, while the subjects in Condition I of this study showed only a moderate reduction in signaled
EFFECTS OF PUNISHMENT ON STUTTERING
235
stuttering expectancies when continuous punishment was administered. This explanation is probably the least credible reason for the difference in findings in view of the fact that continuous punishment usually is more effective than intermittent punishment in reducing response strength. T h e fifth and final interpretation for the differences obtained is believed to be most probable. In the present study, the electrodes were removed from the subjects during the R e c o v e r y period, while the electrodes remained connected to Curlee and Perkins' subjects during their recovery (extinction) period. Thus, the significant reduction in expectancies obtained between Curlee and Perkins' baseline and extinction periods may have resulted because their electrodes remained attached and the threat of shock persisted. Additional research is needed to resolve the questions raised in this discussion and to determine whether punishment for signaled stuttering expectancies is a useful interventive procedure. Indeed, if punishment for a priori responses, such as expectancies, is found to significantly decrease overt stuttering responses, possible rehabilitative implications may be forthcoming. Analysis 2: Effect o f Punishments on Stuttered Utterances
A factorial analysis was used to determine whether the three punishment conditions differently affected the frequency of stuttered utterances in each segment of the experiment. T h e results of this analysis are shown in Table 4. As indicated in this table, the F for Conditions was significant at the .05 level. Specific comparisons revealed that significantly less stuttering (p < .01) occurred during the Training segments of Conditions II and III than in the Training segment of Condition I. As in Analysis 1, this TABLE 4 Summary of Analysis of Variance for the Frequency of Stuttered Utterances Under Three Punishment Conditions Source
df
Between subjects Conditions(A) Subjects within conditions Within subjects Segments (B) Conditions × Segments (AB) Segments x Subjects within conditions
35 2 33 180 5 10 165
a Significant at the .05 level. b Significantat the .01 level.
MS
F
2635.68 526.52
5.02a
1281.04 49.30 28.41
45.09~ 1.74
236
DALY A N D FRICK CONDITION]: (PE) CONDITION1T(P S). . . . . . CONDITIONlit (PES
I00 tn
N 90 Z
'<
8C
~
70
er hi I--
w
60
~
50
(l: w I.-
m
u-
o I-
3O
~ 20
U
,,, Q.
I0 i
BASERATE
i
i
i
i
i
Troiningl Troiring2Tmining3 Training4 RECOVERY
FIG. 2. Mean percentages of stuttering utterances for Base Rate, Recovery, and the four 30-word within-Training groups for eaoh condition.
finding was interpreted carefully because the subjects in Condition I were, on the average, more severe than the subject in the other two conditions. The differences noted when comparing Conditions II and III, however, are viewed with more confidence. The mean differences between the frequencies of stuttering emitted during Conditions II and III of the present study were not significant. This finding indicated that combined punishment, as administered during the Training segment of Condition III, was not a more effective procedure for reducing the frequency of stuttering than the punishment administered for stuttered utterances alone, Condition II. Figure 2 clearly shows that Condition I (punishment of signaled stuttering expectancies) had very little effect on the frequency of overt stuttering utterances. Figure 2 also shows that Conditions II and III had similar effects, even though subjects in Condition III received twice as many electric shocks as subjects in Condition II. TABLE 5 Mean Differences Between the Percentages of Stuttering Utterances of the F o u r 60-Word Segments of Condition II
Base rate Training A Training B
Training A
Training B
Recovery
17.78 a
22.32 a 6.54
19.72 a
a Significant at the .01 level.
-2.60
EFFECTS
OF P U N I S H M E N T
ON S T U T T E R I N G
237
TABLE 6 M e a n Differences Between the Percentages of Stuttering U t t e r a n c e s for the F o u r 60-Word S e g m e n t s of Condition lII
Base rate Training A Training B
Training A
Training B
Recovery
7.37
16.95 b 9.58
12.15 a -4.80
a Significant at the .05 level. b Significant at the .01 level.
To determine if the combined punishment procedure (Condition III) resulted in a greater and a more immediate reduction in the frequency of stuttering than the stuttering utterance contingent punishment procedure alone (Condition II), additional specific mean comparisons were done. The results of these comparisons are shown in Tables 5 and 6. Inspection of Tables 5 and 6 reveals that both punishment procedures effected a significant reduction in the frequency of stuttering by the end of the 120-word Training period (p ~ .01). Contrary to the original assumption, Condition II resulted in a more immediate reduction in stuttering than did Condition III as the frequency of stuttering significantly decreased (p < .01) by the end of Training A (the first 60-words of the punishment segment) in Condition II, but significance was not obtained during the same period in Condition III. Not only was the decrease in the frequency of stuttering obtained in Condition II more immediate than the decrease obtained in Condition IlI, but it was longerlasting; the mean difference in stuttering between the Base Rate and Recovery periods was greater and more persistent for subjects in Condition II (as shown in Table 5) than for subjects in Condition III (as shown in Table 6). One additional finding merits comment. In all three punishment conditions, the increase in the frequency of stuttering which occurred during the Recovery segments did not begin to approach the original base rate levels. DISCUSSION
FOR ANALYSIS
2
The results of this analysis indicate that punishment for stuttering utterances (Condition II) or punishment for both signaled expectancies and stuttering utterances (Condition III) are effective procedures for significantly reducing the frequency of overt stuttering responses. Interestingly, the combined punishment administered in Condition III did not produce more immediate or greater reductions in stuttering than the stuttering utterance contingent punishment procedure used in Condition
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DALY AND FRICK
II. In fact, Condition II was found to be the most effective procedure for reducing the frequency of stuttering. An unexpected finding was that punishment for signaled stuttering expectancies was not an effective procedure for reducing the frequency of stuttering utterances. This finding was in sharp contrast to the results reported in the Curlee and Perkins' study. Because this discrepancy in findings was discussed under Analysis 1, it will not be repeated here. Further research is needed to resolve whether or not punishment for covert responses, such as expectations of stuttering, is an effective procedure for reducing overt stuttering responses. Additional studies which employ longer postpunishment periods also are needed to determine whether or not punishment has only a temporary effect on behavior. Skinner (1938, 1953) and Estes (1944) have argued that punishment serves only to temporarily suppress a response and that it will recur full strength following ,the cessation of the punishment. Data reported by Martin and Siegel (1966) tend to support Skinner's and Estes' contention, as they found an increase in the frequency of stuttering to the base rate level within 20 min following the removal of their shock. Marked recovery did not occur in the present study. However, the Recovery period was relatively short, being only as long as it took the subjects to signal expectancies or nonexpectancies and utter the 60 stimulus words. Further research which incorporates longer recovery periods is needed to test adequately the hypothesis offered by punishment critics such as Skinner and Estes; namely, that complete recovery of a response always occurs if the recovery period is long enough. Longer postpunishment periods may well be the most sensitive index with which to determine the usefulness of punishment procedures. REFERENCES BRAt)V, W. The effect of electric shock on the frequency of stuttering. Master's paper, Pennsylvania State University, 1967. CURLEE, R., & PERKINS, W. The effect of punishment of expectancy to stutter on the frequencies of subsequent expectancies and stuttering. Journal of Speech and Hearing Research, 1968, 11, 787-795. DALY, D., & COOPER, E. Rate of stuttering adaptation under two electroshock conditions, Behaviour Research and Therapy, 1967, 5, 49-54. ESTES, W. An experimental study of punishment, Psychological Monograph, 1944, 57, Whole No. 263. Jort~sor~, W., & BROWN, S. Stuttering in relation to various speech sounds, Quarterly Journal of Speech, 1935, 25, 20-22. MARTIN, R., & SIEGEL, G. The effects of response contingent shock on stuttering, Journal of Speech and Hearing Research, 1966, 9, 340-352.
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SKINNER, B. Science and human behavior. New York: Macmillan, 1953. SKINNER, B. The behavior o f organisms. New York: Appleton-Century, 1938. THORNDIKE, E., & LORGE, I. The teacher's word book o f 30,000 words. New York: Teachers College, Columbia University, 1944. WINER, B. Statistical principles in experimental design. New York: McGraw-i-Iill, 1962.
The Effects of Punishing Stuttering Expectations and Stuttering Utterances: A Comparative Study 1 DAVID A. DALY 2
University of Alabama in Birmingham AND JAMES V . FRICK
Pennsylvania State University The effects of contingent shock,on signaled stuttering expectancies and/or stuttering utterances were studied in 36 adult male stutterers. Each subject participated in only one of three different punishment conditions. Each condition consisted of three segments: Base Rate, Training, and Recovery. Punishment was administered only during the Training segments. Electroshock was delivered contingent upon signaled expectancies to stutter in one condition; in a second condition, shock was administered for emitted stuttering utterances; and in the third condition, the effect of punishment for both signaled expectancies and stuttered utterances was studied. The general findings were: (a) significant differences existed among conditions with respect to both the frequency of signaled stuttering expectancies and the frequency of stuttering utterances; (b) punishment of signaled expectancies effected only a moderate reduction in additional stuttering expectancies; (c) stuttering utterance contingent shock effected a significant decrease in stuttering; and (d) the combined punishment procedure effected significant reductions in both signaled expectancies and stuttering utterances. A major finding was that the combined punishment procedure did not effect a more immediate or a more significant reduction in stuttering than the stuttering utterance contingent punishment procedure.
Several investigators who have employed electric shock as a form of punishment for stuttering have reported that the frequency of stuttering is markedly reduced in the laboratory when shock is administered contingent upon stuttered utterances. For example, Martin and Siegel (1966) found that response contingent electric shock was effective in decreasing stuttering, with the introduction of shock resulting in almost a total reducThis investigation was supported in part by United Cerebral Palsy Research and Educational Foundation Grant No. T-779-68, obtained through the American Speech and Hearing Foundation. This report was based on Daly's dissertation completed at the Pennsylvania State University in 1968 under the direction of Frick. Reprints may be obtained from David A. Daly, Ed. D., Center for Developmental and Learning Disorders, University of Alabama in Birmingham, 1919 Seventh Avenue South, Birmingham, Alabama 35233. 228
E F F E C T S OF P U N I S H M E N T
ON S T U T T E R I N G
229
tion of stuttering for all three of their subjects. Daly and Cooper (1967) and Brady (1967) also found marked reductions in the frequency of stuttering during their stuttering contingent electroshock conditions. The results of a recent investigation by Curlee and Perl~ins (1968) indicated that punishment (electric shock) for signaled expectations of stuttering effected a significant decrease in both the frequency of stuttering utterances and further stuttering expectancies. Curlee and Perkins utilized three conditions, four subjects per condition. Each condition consisted of three segments: a baseline measurement period in which the frequency of signaled expectancies to stutter and instances of stuttering prior to punishment were counted; a training period in which the punishment was administered; and an extinction period to determine the effect of the punishment following conditioning. Single words were used as stimuli and the training periods varied as follows: Experimental group. Subjects were shocked immediately following their signaled stuttering expectancies; however, the shock was administered on a predetermined variable-ratio schedule. Interestingly, whenever a subject was shocked, he was not allowed to say the sentence he composed and therefore did not stutter on the stimulus word. Yoked-control group. Subjects were paired with, and received the same number of shocks per 50-word grouping as the subjects in the experimental group. However, the shock was not administered immediately following a signaled expectancy to stutter; rather, it was administered randomly at least 5 sec after a sentence had been said and 5 sec before the presentation of the next stimulus word. Time-control group. Subjects signaled their expectancies to stutter, and although they were "wired for shock," it was not administered. Curlee and Perkins' analyses were based upon the difference scores between the frequency of signaled stuttering expectancies obtained during the baseline and extinction periods and the difference scores between the frequency of stuttering utterances obtained during the same periods. They found that punishment of expectancy to stutter was associated with significant decreases in the frequencies of both expectancy and stuttering. Specifically, the decrease in their experimental or shock-contingent group was significantly greater than in either control group. The significant reductions in both stuttering expectancies and stuttering utterances which Curlee and Perkins found lead to several interesting questions. The major question we were interested in was: "Would punishing stutterers for both their signaled expectancies and their overt stuttering utterances result in a greater and a more immediate reduction
230
DALY AND FRICK
in the frequency of stuttering than the type of procedure in which stutteri n g e x p e c t a n c i e s or s t u t t e r i n g u t t e r a n c e s a l o n e a r e p u n i s h e d ? " A s e c ondary purpose of the present experiment was to determine if 100% punishment for signaled stuttering expectancies would result in similar reductions to Curlee and Perkins' findings using intermittent punishment. METHOD
Subjects Individuals who stuttered at least 5% of the time when reading 40 practice words were selected as subjects. A 5% criterion was used to insure that all subjects demonstrated stuttering behavior and to allow for possible reductions in stuttering expectancies and/or stuttering utterances which might have resulted from the different punishments administered. From a total of 49 stutterers, 36 male subjects reached the 5% criterion. Twelve of the 13 stutterers who were not selected as subjects did not stutter or expect to stutter on at least 5% of the practice words. The other stutterer who was not selected was a severe stutterer; however, he experienced difficulty reading the 40 practice words and was excluded because of his reading problem. The ages of the 36 subjects selected ranged from 17 to 42 years, with a mean age of 23 years. The number of months in speech therapy ranged from 1 month to 15 years, with the mean therapy time being 3.5 years.
Materials Fourteen words for each of the 20 initial consonant sounds found by Johnson and Brown (1935) to evoke the greatest amount of stuttering were selected from Thorndike and Lorge's (1944) text. Only words of two or more syllables were considered, and, to control for familiarity, words were chosen from Thorndike and Lorge's category "words occurring at least once per 1,000,000 words." From the total list of 280 words (14 for each of the 20 consonant sounds), 6 words were randomly selected from each consonant classification to constitute the Training words. Three words from each phoneme class were chosen for the Base Rate words, and three were randomly chosen for the Recovery words. The 40 remaining words were used as the reading stimuli in the practice session. A slide was made for each word and the stimuli were presented via a projector.
Instrumentation A commercially constructed punishing device (Electronic Stimulator, Model 751) was used to deliver the shock. This instrument had the capacity to deliver a shock with an intensity of 0.15 to 150 V. A metal box was built for the subjects to use to signal whether or not they expected to stutter when seeing each stimulus word. The box contained two buttons: a red button on the right surface of the box to be pushed when stuttering was expected, and a black button on the left surface of the box to be pushed when stuttering was not expected. The two signaling buttons were connected to an automatic counter (Easterline Angus graphic ammeter, Model AW) which provided a record of each subject's signaled expectancies and nonexpectancies to stutter.
EFFECTS OF PUNISHMENT ON STUTTERING
231
Procedure Each subject was seated at a table with the box positioned in front of him. The stimulus words were individually shown on a wall approximately 6 feet from the subject. A red light came on 3 sec after each word was exposed. This light indicated that the subject should signal whether or not he expected to stutter on the word when saying it aloud. Following each decision, a green light was turned on at intervals varying from 1, 2, 3, 4, or 5 sec. The green light was the signal for the subject to say the stimulus word. Each subject was randomly assigned to one of three different punishment conditions, so there were 12 subjects in each condition. Each condition consisted of three segments: Base Rate, Training, and Recovery. Base Rate. The Base Rate segment consisted of 60 stimulus words and provided a baseline measure of each subject's frequency of signaled stuttering expectancies and frequency of stuttering utterances prior to the administration of the punishment. Training. Following the Base Rate segment, two electrodes were attached to each subject and his threshold for pain was determined. The subjects' pain thresholds ranged from 50 to 140 V with the mean pain threshold being 96.25 V. The intensity of the shock received by each subject was 5 V above his pain threshold. During the 120 word Training segment electric shock was administered contingent upon the specified response or responses to be punished in the respective conditions. Subjects in Condition I were punished immediately following each signaled stuttering expectancy; subjects in Condition II were punished immediately following each stuttered word; and subjects in Condition III were punished immediately following both signaled expectancies to stutter and actual stuttering utterances. Recovery. When the subjects finished reading the 120 words in the Training segment, the electrodes were removed. However, the subjects continued to signal their anticipations of stuttering on an additional 60 words which constituted the Recovery segment. Shock or threat of shock was not a factor in this segment as there was no possibility of being punished.
Responses Each subject's signaled expectancies and nonexpectancies were recorded electronically with an automatic counter which was connected to the two signaling buttons. Stuttered words were recorded on a score sheet by the experimenter. His competence to determine stuttering utterances was obtained by comparing his judgment with two experienced professors in speech pathology. The interjudge reliability obtained was 96%. RESULTS The percentages of signaled stuttering expectancies and the percenta g e s o f s t u t t e r i n g u t t e r a n c e s a r e p r e s e n t e d in T a b l e 1 a n d T a b l e 2, r e s p e c t i v e l y . T h e 1 2 0 - w o r d T r a i n i n g p e r i o d w a s d i v i d e d i n t o t w o 6 0 - w o r d segm e n t s ( T r a i n i n g A a n d T r a i n i n g B) t o s h o w w h e t h e r t h e p u n i s h m e n t s employed had an immediate or a continuous effect. In order to answer the questions asked, the data were analyzed using two factorial designs with repeated measures on one of the factors (after W i n e r , 1962). T h e s e t w o a n a l y s e s w i l l b e d i s c u s s e d s e p a r a t e l y . I n b o t h a n a l y s e s t h e t h r e e d i f f e r e n t p u n i s h m e n t c o n d i t i o n s w e r e c o n s i d e r e d as
232
DALY AND FRICK TABLE 1 Mean Percentages of Signaled Stuttering Expectancies for the Four 60-Word Segments According to Conditionsa
Conditions
Base Rate
Training A
Trmning B
Recovery
I
47
42
38
42
II III
32 27
23 19
17 ll
13 16
a Twelve s u ~ e c t s i n each condition. TABLE 2 Mean Percentages of Stuttering Utterances for the Four 60-Word Segments According to Conditionsa Conditions
Base Rate
Trmning A
Training B
Recovery
I
47
45
42
42
II III
33 27
15 19
11 10
12 15
a Twelve subjects in each condition.
one factor, while the segments in each condition were considered as the other.
Analysis 1: Effect of Punishments on Signaled Stuttering Expectancies This factorial analysis tested whether the three punishment conditions differently affected the frequency of stuttering expectancies in each segment of the experiment. The results of this analysis, as shown in Table 3, revealed that there was a significant difference (p < .05) among the TABLE 3 Summary of Analysis of Variance for the Frequency of Signaled Stuttering Expectancies Under Three Punishment Conditions Source
df
Between subjects Conditions (A) Subjects within conditions Within subjects Segments (B) Conditions x Segments (AB) Segments x Subjects within conditions
35 2 33 180 5 10 165
a Significant at the .05 level. b Significant at the .01 level.
MS
1973.07 452.25 1340.00 72.80 24.12
F
4.3627 a
55.53 b 3.020
233
EFFECTS OF PUNISHMENT ON STUTTERING
frequencies of signaled expectancies in the three punishment conditions. Specific comparisons revealed that the frequencies of stuttering expectancies signaled during the Training segments of Conditions II and III were significantly lower (p < .01) than the frequency of expectancies signaled during the Training period in Condition I. This finding, however, was interpreted with caution because the 12 stutterers randomly assigned to Condition I were, by chance, more severe than the stutterers assigned to the other two conditions. Although differences obtained between the subjects in Condition II and Condition III were viewed with more confidence, these differences were not statistically significant. Thus, the results of this study indicate that combined punishment, as administered in Condition III, was not a more effective procedure for reducing stuttering expectancies than the punishment administered for stuttered utterances alone, Condition II. Figure 1 clearly shows that the subjects in all conditions reduced the frequency of their stuttering expectancies in their respective Training periods. The 120-word Training periods were divided into four 30-word segments to permit precise visual inspection of the changes which occurred throughout the punishment periods. The small increases in the frequency of signaled expectancies which occurred in the Recovery segments of Conditions I and III did not begin to approach the Base Rate level of responding. Thus, marked spontaneous recovery of expectancies to stutter was not found in this study. In fact, further reduction in the frequency of stuttering expectancies was noted in the Recovery period of Condition II. CONOITION I
IOO
CONDITION Tr .
~ 90
,, ,,
,
. . . . .
C ONOITION TIT~ , w ~ = -
~ 801
×"=~oi bJ 6C ._1 z,~ 5c ¢n 4 0
w 30, Z bJ
2o ~
w
I
I
BASE RATE Troiningl
I
I
I
I
Training2 Training3 Troining4 RECOVERY
FIG. 1. Mean percentages of signaled stuttering expectancies for Base Rate, Recovery, and the four 30-word within-Training groups for each condition.
234
DALY AND FRICK DISCUSSION
FOR ANALYSIS
1
The results obtained indicate that punishment for stuttering utterances (Condition II) and punishment for both signaled expectancies and stuttering utterances (Condition Ill) were more effective procedures for reducing the frequency of signaled expectancies than punishment for signaled stuttering expectancies alone (Condition I). These findings were considered with care because the higher percentage of signaled expectancies in Condition I was apparently the result of a greater proportion of severe stutterers in that condition. One purpose of the present study was to determine if 100% punishment for signaled stuttering expectancies would yield similar results to those obtained by Curlee and Perkins (1968) using intermittent punishment. In their comparison of three different conditions, they found that shock for signaled stuttering expectancies resulted in the greatest reduction of subsequent expectancies when compared to their two control conditions. The results of the present investigation do not agree with Curlee and Perkins' findings. Five possible explanations for the difference in findings are offered. First, the severe stutterers in Condition I of this study may possibly have masked any marked reduction which might have occurred if moderate or mild stutterers had comprised the group. One cannot tell from Curlee and Perkins' study whether the four subjects in their stuttering contingent punishment condition were severe, moderate, or mild stutterers. Second, the stimulus words used in the two studies differed in difficulty. Curlee and Perkins' selected words from the Throndike and Lorge (1944) list of most frequently used 1000 words. These words are common and, for the most part, only one syllable in length. The stimulus words chosen for the present study were less common (occurring only once per 1,000,000 words) and consisted of two or more syllables. The third explanation for Curlee and Perkins' greater reduction in expectancies may be that their Training segment was over three times as long as the Training segment of the present study. Specifically, Curlee and Perkins' Training period lasted until 400 stimulus words had been said or until 2 hr had passed, whichever occurred first, whereas the Training segment in this study lasted only as long as it took each subject to signal and utter the 120 stimulus words. The fourth reason offered to explain the difference in findings may be that the schedules of punishment were different for the two studies. Curlee and Perkins' subjects significantly reduced their signaled stuttering expectancies when intermittent shock was used, while the subjects in Condition I of this study showed only a moderate reduction in signaled
EFFECTS OF PUNISHMENT ON STUTTERING
235
stuttering expectancies when continuous punishment was administered. This explanation is probably the least credible reason for the difference in findings in view of the fact that continuous punishment usually is more effective than intermittent punishment in reducing response strength. T h e fifth and final interpretation for the differences obtained is believed to be most probable. In the present study, the electrodes were removed from the subjects during the R e c o v e r y period, while the electrodes remained connected to Curlee and Perkins' subjects during their recovery (extinction) period. Thus, the significant reduction in expectancies obtained between Curlee and Perkins' baseline and extinction periods may have resulted because their electrodes remained attached and the threat of shock persisted. Additional research is needed to resolve the questions raised in this discussion and to determine whether punishment for signaled stuttering expectancies is a useful interventive procedure. Indeed, if punishment for a priori responses, such as expectancies, is found to significantly decrease overt stuttering responses, possible rehabilitative implications may be forthcoming. Analysis 2: Effect o f Punishments on Stuttered Utterances
A factorial analysis was used to determine whether the three punishment conditions differently affected the frequency of stuttered utterances in each segment of the experiment. T h e results of this analysis are shown in Table 4. As indicated in this table, the F for Conditions was significant at the .05 level. Specific comparisons revealed that significantly less stuttering (p < .01) occurred during the Training segments of Conditions II and III than in the Training segment of Condition I. As in Analysis 1, this TABLE 4 Summary of Analysis of Variance for the Frequency of Stuttered Utterances Under Three Punishment Conditions Source
df
Between subjects Conditions(A) Subjects within conditions Within subjects Segments (B) Conditions × Segments (AB) Segments x Subjects within conditions
35 2 33 180 5 10 165
a Significant at the .05 level. b Significantat the .01 level.
MS
F
2635.68 526.52
5.02a
1281.04 49.30 28.41
45.09~ 1.74
236
DALY A N D FRICK CONDITION]: (PE) CONDITION1T(P S). . . . . . CONDITIONlit (PES
I00 tn
N 90 Z
'<
8C
~
70
er hi I--
w
60
~
50
(l: w I.-
m
u-
o I-
3O
~ 20
U
,,, Q.
I0 i
BASERATE
i
i
i
i
i
Troiningl Troiring2Tmining3 Training4 RECOVERY
FIG. 2. Mean percentages of stuttering utterances for Base Rate, Recovery, and the four 30-word within-Training groups for eaoh condition.
finding was interpreted carefully because the subjects in Condition I were, on the average, more severe than the subject in the other two conditions. The differences noted when comparing Conditions II and III, however, are viewed with more confidence. The mean differences between the frequencies of stuttering emitted during Conditions II and III of the present study were not significant. This finding indicated that combined punishment, as administered during the Training segment of Condition III, was not a more effective procedure for reducing the frequency of stuttering than the punishment administered for stuttered utterances alone, Condition II. Figure 2 clearly shows that Condition I (punishment of signaled stuttering expectancies) had very little effect on the frequency of overt stuttering utterances. Figure 2 also shows that Conditions II and III had similar effects, even though subjects in Condition III received twice as many electric shocks as subjects in Condition II. TABLE 5 Mean Differences Between the Percentages of Stuttering Utterances of the F o u r 60-Word Segments of Condition II
Base rate Training A Training B
Training A
Training B
Recovery
17.78 a
22.32 a 6.54
19.72 a
a Significant at the .01 level.
-2.60
EFFECTS
OF P U N I S H M E N T
ON S T U T T E R I N G
237
TABLE 6 M e a n Differences Between the Percentages of Stuttering U t t e r a n c e s for the F o u r 60-Word S e g m e n t s of Condition lII
Base rate Training A Training B
Training A
Training B
Recovery
7.37
16.95 b 9.58
12.15 a -4.80
a Significant at the .05 level. b Significant at the .01 level.
To determine if the combined punishment procedure (Condition III) resulted in a greater and a more immediate reduction in the frequency of stuttering than the stuttering utterance contingent punishment procedure alone (Condition II), additional specific mean comparisons were done. The results of these comparisons are shown in Tables 5 and 6. Inspection of Tables 5 and 6 reveals that both punishment procedures effected a significant reduction in the frequency of stuttering by the end of the 120-word Training period (p ~ .01). Contrary to the original assumption, Condition II resulted in a more immediate reduction in stuttering than did Condition III as the frequency of stuttering significantly decreased (p < .01) by the end of Training A (the first 60-words of the punishment segment) in Condition II, but significance was not obtained during the same period in Condition III. Not only was the decrease in the frequency of stuttering obtained in Condition II more immediate than the decrease obtained in Condition IlI, but it was longerlasting; the mean difference in stuttering between the Base Rate and Recovery periods was greater and more persistent for subjects in Condition II (as shown in Table 5) than for subjects in Condition III (as shown in Table 6). One additional finding merits comment. In all three punishment conditions, the increase in the frequency of stuttering which occurred during the Recovery segments did not begin to approach the original base rate levels. DISCUSSION
FOR ANALYSIS
2
The results of this analysis indicate that punishment for stuttering utterances (Condition II) or punishment for both signaled expectancies and stuttering utterances (Condition III) are effective procedures for significantly reducing the frequency of overt stuttering responses. Interestingly, the combined punishment administered in Condition III did not produce more immediate or greater reductions in stuttering than the stuttering utterance contingent punishment procedure used in Condition
238
DALY AND FRICK
II. In fact, Condition II was found to be the most effective procedure for reducing the frequency of stuttering. An unexpected finding was that punishment for signaled stuttering expectancies was not an effective procedure for reducing the frequency of stuttering utterances. This finding was in sharp contrast to the results reported in the Curlee and Perkins' study. Because this discrepancy in findings was discussed under Analysis 1, it will not be repeated here. Further research is needed to resolve whether or not punishment for covert responses, such as expectations of stuttering, is an effective procedure for reducing overt stuttering responses. Additional studies which employ longer postpunishment periods also are needed to determine whether or not punishment has only a temporary effect on behavior. Skinner (1938, 1953) and Estes (1944) have argued that punishment serves only to temporarily suppress a response and that it will recur full strength following ,the cessation of the punishment. Data reported by Martin and Siegel (1966) tend to support Skinner's and Estes' contention, as they found an increase in the frequency of stuttering to the base rate level within 20 min following the removal of their shock. Marked recovery did not occur in the present study. However, the Recovery period was relatively short, being only as long as it took the subjects to signal expectancies or nonexpectancies and utter the 60 stimulus words. Further research which incorporates longer recovery periods is needed to test adequately the hypothesis offered by punishment critics such as Skinner and Estes; namely, that complete recovery of a response always occurs if the recovery period is long enough. Longer postpunishment periods may well be the most sensitive index with which to determine the usefulness of punishment procedures. REFERENCES BRAt)V, W. The effect of electric shock on the frequency of stuttering. Master's paper, Pennsylvania State University, 1967. CURLEE, R., & PERKINS, W. The effect of punishment of expectancy to stutter on the frequencies of subsequent expectancies and stuttering. Journal of Speech and Hearing Research, 1968, 11, 787-795. DALY, D., & COOPER, E. Rate of stuttering adaptation under two electroshock conditions, Behaviour Research and Therapy, 1967, 5, 49-54. ESTES, W. An experimental study of punishment, Psychological Monograph, 1944, 57, Whole No. 263. Jort~sor~, W., & BROWN, S. Stuttering in relation to various speech sounds, Quarterly Journal of Speech, 1935, 25, 20-22. MARTIN, R., & SIEGEL, G. The effects of response contingent shock on stuttering, Journal of Speech and Hearing Research, 1966, 9, 340-352.
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239
SKINNER, B. Science and human behavior. New York: Macmillan, 1953. SKINNER, B. The behavior o f organisms. New York: Appleton-Century, 1938. THORNDIKE, E., & LORGE, I. The teacher's word book o f 30,000 words. New York: Teachers College, Columbia University, 1944. WINER, B. Statistical principles in experimental design. New York: McGraw-i-Iill, 1962.