- Email: [email protected]
Implosion therapy by tape-recording
Behav Res. & Therap).
1975. Vol
13. pp. 177-182. Pergamon Press. Prmted m Great Bntam
CASE HISTORIES
AND SHORTER
COMMUNICATIONS
Implosion therapy by tape-recording (Rrwicctl
3 Juw
1971)
According to the model proposed by Stampfl and Levis (1967).implosion reduces fear by evoking anxiety in the presence of cues associated with the phobic object. but in the absence of primary reinforcement. An essential requirement for rapid therapeutic effect is that the patient be made to experience intense affect. since “the greater the non-reinforced anxiety experienced. the greater the extinction of fear” (Hogan and Kirchner. 1967). Thus. the patient is repeatedly presented with fear-evoking sttmuli and kept at a high level of arousal until ‘a significant diminution in anxiety has resulted (Stampfl and Levis. 1967). Thts model assumes that this ‘significant diminution in anxiety’ is equivalent to extinction of the fear response. Only a handful of studies of implosion. usmg human subjects. have attempted to relate the pattern and magnitude of fear during therapy to outcome measures. Hogan and Kirchner (1967) measured heart rate continuously throughout implosion. Compared to a no-treatment control procedure. implosion generated significantly greater heart rate arousal during therapy and greater behavioral improvement at assessment. suggesting support for the extmction model. In contrast. Watson and Mat% (1971) found no correlation between overt anxiety during flooding and measures of outcome. Stern and Marks (1973) found ‘little skin conductance activity or tachycardia’ during flooding in fantasy. rather than the high level of arousal required by StampR’s model. The present study attempted a partial test of some of the model’s assumptions within the context of an outcome study of implosion therapy by tape recording. Kirchner and Hogan (1966) have claimed that a single, brief session of implosion therapy by tape recording can dramatically reduce phobic avoidance behavior. However. Hodgson and Rachman (1970) and Fazio (1970) failed to replicate these results. Findings from these and other studies of implosion are difficult to interpret because of the absence of objective measures of fear during the therapy session. In the absence of such measures. it is difficult to judge whether the implosive procedures succeeded in creating the pattern of arousal demanded by StampR’s model. Failure to meet the requirements of the model might account for the failures to replicate. The present study included physiological and subjective measures of fear during therapy in an attempt to replicate the Kirchner and Hogan (1966) experiment. using double-blind methodology and a placebo control. It was expected that after exposure to a tape recorded session of implosive therapy, rat phobic subjects would demonstrate significantly greater improvement than controls on a behavioral avoidance test and a questionnaire. In conformity with the extinctton model. it was predicted that the implosion group would manifest greater average fear. as well as a significant reduction in fear. during therapy. and that measures of fear during therapy and at assessment would be correlated. METHOD
The Ss were 24 female undergraduates ioral avoidance test.
selected for rat-phobia
by a fear questionnaire
and a subsequent
behav-
Apparatus Heart rate was monitored with a Grass Model 7 polygraph. electrodes. A stereo tape recorder with a fixed sound intensity
using a cardiotachometer and conventional setting was used to play the tape recordings.
EKG
A modified version of the Fear Survey Schedule (Wolpe and Lang. 1964) was distributed to approximately 750 undergraduates. Only those 61 females who rated their fear of rats as maximal were contacted and asked to volunteer for “an experiment to test a new form of therapy which had proven effective in eliminating fears”. At the first session. El administered a pretreatment behavtoral avoidance test (BTI). following a procedure similar to that of Davison (1968). Ss gave a subjectivje rating on a I-10 scale of their fear at each step of the test. Only those 24 Ss who refused to touch the rat were asked to contmue in the study. Ss filled out a 24-item. truefalse rat questionnaire. which asked how thev reacted to rats m v*arious real-life situations. All scores were coded. and Ss were matched on the basis of behavioral performance and randomly assigned to three groups. 8 Ss per group: implosion therapy (IT). mformational placebo UP). and no-treatment (NT). At the start of the second session, each S was met individually by a female assistant. E2. who attached electrodes and monitored heart rate for I5 min to establish a base rate. At the end of the base rate period. E2 learned the Ss group assignment from a coded card and proceeded with the therapy sessron. 177
178
CASE HISTORIkS
AND
SHORTFR
COMML’UICATIONS
Grou/l IT. This group heard a 39-mm. standardized. tape recorded session modeled after the one developed and Hogan (1966). Ss were told. by way of rationale. that the therapy was based on the prmciple that “the best way to eliminate fear is to face up to it”. It was explained that the tape would Include some terrifying imagery. and Ss were mstructed to allow themselves to experience as much fear as possible. Group IP. This group heard a 39-min. tape recorded informational placebo. which presented factual information about the life habits of rats. read from scientific articles. The contents were selected to be as mnocuous as possible. Ss were told that the therapy was based on the principle that “the best way to eliminate fear is to learn more about the thing you lear.” They were told that the tape vvould provide factual information without arousing fear, and they were instructed to relax as much as possible. Group N7: No tape recording was played. E2 informed this group that “due to a mechanical failure in the polygraph”. there would be a delay before therapy could begin. Heart rate was monitored continuously during therapy, immediately lollowmg which El administered another behavioral test (BTU). on a double blind basis. following the same procedure used in BTI. All Ss then completed the rat questionnaire for the second time. Ss from groups IT and IP also filled out a therapy questionnatre (TQ). This included a self-report rating. on a l-5 scale. of both the average (TQ Average) and maximal (TQ Max) amounts of fear experienced during the therapy session. The TQ also asked for ratings of the clarity of imagery attained during therapy, the amount of faith the S had in the therapy, both before and after treatment. and the amount of pressure the S felt to perform tasks during BTI and BTII. At a follow-up session. about one week later. El repeated the behavioral test (BTIII). by Kirchner
RFSL’LTS
Figure I shows the average number of BT items completed by each group during BTI and BTII. As predicted. group IT changed the most, followed in turn by groups IP and NT. BT change scores (BT-CS) were computed for each S, using the method of Lang and Lazovik (1963):
BT-CS =
number
of items BTII - number number
of items BTI
of items BTI
An analysis of variance, using these changes scores. found no statistically significant diflerences between groups (F = 1.58.4f = Z/21). When scores on BTII and BTHI were compared within each group. no significant change in behavior was found. Figure 2 shows the results on the self-report measure of fear taken during each behavioral test. For a given Sand a given behavioral test. the behavioral test fear score (BTFS) was defined as the sum of verbal fear ratings divided by the number of BT items successfully completed. In computmg BTFS’s for BTII and BTIII. only those ratings from tasks which had been completed during BTI were included. In contrast to the commonly used fear thermometer, this method of scoring controls for differential progress on the behavioral test. As can be seen in Fig. 2. it was group IP, not group IT. that showed the greatest drop in fear on this measure. A behavioral test fear change score (BTF-CS) was computed for each S as follows: BTFS on BTI - BTFS on BTII BTF_CS = ~______..___ BTFS on BTI An analysis of variance. using these change scores. revealed significant group differences. Subsequent comparisons showed significant differences between group IP and each of the other groups. hut no significant differences between groups IT and NT (see Table I).
Fig. I. The average
number
of behavioral test items successfully (BTI) and after (BTII) therapy.
completed
by each group
before
CASE HISTORIES
Fig. 2. The average
Table
Source Between Within Total
subjective
ASD
SHORTER
179
COMML’UKATIOVS
fear reported by each group on a I-IO scale.
I. Analysis of variance for behavioral
during
BTI and BTU. Ratings
test fear change
were
scores
SS
4f
MS
F
P
0.04 I.17 I.57
2 21 23
0.200 0.056
3.57
0.05
Duncan Multiple Range Test: Treatment totals: Group NT = 2.44: Group IT = 2.54: Group Observed values: IP vs NT: 2.24, 11 < 0.05: IT vs NT: 0.10: IP vs IT: 1.14. ,’ < 0.05. There were no significant differences between groups from BTI to BTII (F = 0.80. df = 2 ?O).
in terms of the amount
Both the TQ Average and the TQ Max scores indicated significantly in group IT than in group IP (TQ Average: I = 5.18. [lf = 14. p < 0.01: In order to obtain average scores. heart rate was computed at I-min period and throughout therapy. As expected. group IT showed an overall a fall in average heart rate between base and therapy periods (see Fig. 3). computed for each S as follows: average HR_CS = __L__
therapv
h.r. - average
average
IP = 4.6X.
of change on the rat questionnaire
greater subjective fear during therapy TQ Max: t = 5.97. dJ= 14. P < 0.01). intervals during the last 5 min of baserise. while groups IP and NT showed Heart rate change scores (HR-CS) were base h.r.
base h.r.
An analysis of variance revealed significant differences between group IT and each of the other groups. but no significant differences between groups IP and NT (see Table 2). These results support the contention that implosion produced significantly greater fear arousal than either placebo or no-treatment procedures. For implosion and placebo Ss. the TQ Average score correlated significantly with the HR-CS measure (r = 0.56). indicating that Ss reporting the greatest average fear during therap! demonstrated the greatest increase in heart rate between base and therapy periods. To determine the pattern of heart rate arousal during therapy Itself. heart rate was averaged into 5-min blocks oftime during the first 25 min oftherapy and durmg minutes 34 through 3X at the end. The graph in Fig. 4 shows the predicted pattern ofarousal. with group IT rising to a plateau within the first 10 min. stabilizing at this level, and then falling towards base levels. Compared with group IP. group IT showed significantly higher peaks of arousal during minutes l-25 of therapy (t = 2.87. L!/‘= 14. p < 0.025). Within group IT. the fall in heart rate from the highest level during minutes l--25 to the average level during mmutes 34-3X was statistically signiiicant Table 2. Analysis Source Between Within Total
of variance
for heart rate change
scores
ss
o/
MS
F
P
0.096 0. I 7 I 0.267
2
0.048
6.00
0.01
21
0.00x
23
DuncanMultipleRangeTest:Treatment totals: Group NT = -0.358:Group IT = +0.81X;Group Observed values: IP vs NT: 0.256: IT vs NT: 1.176. p < 0.01: IP vs IT: 0.920. p c; 0.05.
IP = -0.102.
180
CASE HISTORIES
ANI)
SHOHTEK
76L
Base-period
COMMLNICATIONS
Therapy-period
Fig. 3. Computations of heart rate were made at l-mm intervals during the last 5 min of baseperiod and throughout therapy in order to arrive at the average heart rate of each group durmg base and therapy periods. (t = 2.45. df= 7, p < 0.05). A similar analysis within group IP failed to achieve significance (r = 1.10. &= 7). There were no significant differences between the average heart rate scores of groups _ . IT and IP during minutes 34-38 (I = 1.35. $= 14). Thus, although the groups differed in maximal heart rate arousal during the first half of therapy, no significant difference remained at the end of the session. The pattern of significant arousal followed by significant decline shown by the implosion group conformed to the requirements of the extinction model proposed by Stampfl and Levis ( 1967).
Fig. 4. In order to demonstrate the heart rate pattern during therapy. heart rate was averaged into 5-mitt blocks of time.
Correlations were computed between measures of fear during therapy and the two behavioral-test measures of outcome. As shown in Table 3. the only statisttcally significant result was a negative correlation of I’ = -0.58 between the two self-report measures of fear. the TQ Average and the BTF-CS. indicating that Ss reporting the greatest average fear during therapy tended to report the lrusr improvement at assessment. In a separate computation. a correlation of r = 0.66 was found between the HR-CS and the fall in heart rate from peak to final levels within group IT. This relationship was significant at p < 0.05 if considered as 3 one-tail test of an a priori hypothesis. An analogous computation within group IP did not approach significance. Table 3. Correlations between measures of fear during therapy and fear at outcome
TQ Average
Outcome BT-CS BT-FCS
* p < 0.01.
Fear during therapy Heart rate change scores
Fall in heart rate from peak to final levels
IT
IT + IP
IT
IT+ IP
+ 0.20
- 0. I I
- 0.02
+0.36
-05X’
+ 0.52
- 0.04
+0.36
+0.18 to.14
IT
IT f IP
+ 0.32 - 0.56
CASE
HISTORIES
AND
SHORTER
COMMUNICATIONS
181
When groups IT and IP were compared on the remaining questions from the therapy questionnaire. no significant differences were found.
DISCUSSION
experimen~l demonstration with human SS that a session of implosion therapy can produce the pattern of fear arousal described by Stampff’s model. Tape recorded imPkxion ewxated Significantly greater fear arousal than control procedures. and implosion SS showed the predicted pattern of heart rate change during therapy. However, the results did not support the claims of Kirchner and Hogan (1966) that a single. brief session of implosion therapy by tape recording is a particularly effective treatment. The prediction that the imP1osion group would show significantly greater therapeutic change than placebo or controls was not confirmed. These findings are in accord with the failures to replicate reported by Fazio (1970). and Hodgson and Rachman (1970). It is noteworthy that Hodgson and Rachman’s implosion group demonstrated slightly greater improvement over controls as measured by behavioral performance but poorer improvement as measured by self-report, precisely the pattern shown by the implosion and placebo groups in this study. Some limitations of the present study bear comment. For one thing. the implosion session tasted only 39 min. It has been reported that longer durations are generally more effective (Stern and Marks 1973). Also, this study included only one session of implosion. whereas clinicians routinely administer multiple sessions. Another limitation was that therapy was conducted by tape recording rather than in person. Tape recordings have generally been found to be less effective than a live therapist (Stern and Marks. 1973). Although necessary in order to replicate Kirchner and Hogan’s procedure, these limitations may, in part. account for the disappointing outcome. Hogan and Kirchner (1967)contended that “the greater the nonreinforced anxiety experienced. the greater the extinction of the fear’.. A modest, but statistically nonsignificant. correlation of 0.52 within the implosion group suggested a possible relationship between a rise in heart rate from base to therapy levels, on the one hand, and a decline in self-reported fear on the behavioral test. on the other. With a larger sample. a significant relationship might have emerged. Somewhat stronger support was provided by the finding of a significant 0.66 correlation within group IT between a rise in average heart rate from base to therapy levels and a fall in heart rate during therapy from peak to final levels. However, Hogan and Kirchner’s hypothesis failed to account for many of the findings regarding behavioral and subjective measures of fear. Although group IT showed an overall pattern of fear arousal in conformity with the extinction model. implosion subjects did not demonstrate significantly greater improvement at outcome as measured by behavioral performance or self report. Also. there was evidence that Ss reporting the greatest fear during therapy tended to report the least improvement at outcome. This latter finding. seemingly a direct contradiction of Hogan and Kirchner’s predictions. implies that some Ss may have been adversely affected by intensive fear arousal. This is reminiscent of the clinical report by Wolpe (1958) that_ in desensitization. “a stimulus that is too strong may actually increase sensitivity”. a process he calls ‘sensitization’. It is possible that ‘sensitization” may underlie some of the reported failures to achieve therapeutic success using implosive techniques, especially in briefer courses of therapy. Stampfl and Levis (1967) emphasize the importance of continuing the implosive process until “a significant diminution in anxiety has resulted”. In the present research. only group IT showed a significant diminution in heart rate during therapy; but it did not show signifi~ntly greater improvement than controls at assessment. in addition. there was no significant correlation within group IT between the fall in heart rate during therapy and any of the outcome measures. Space does not permit adequate discussion of whether the decline m heart rate seen during the implosive session is best designated ‘habituation’ or ‘extinction’. However. tt should be noted that. within the context of StampR’s writings. a diminution in fear arousal. even within a single session. is tantamount to ‘extinction’: “At each stage of the process an attempt is made by the therapist to attain a maximal level of anxiety evocation from the patient. When a high level of anxiety is achieved. the patient is held on this level until some sign of spontaneous reduction in the anxiety-inducing value of the cues appears (extinctionr (Stampfl and Levis. 1967). Although the present research indicated that Stampfl’s model correctly described the pattern and magnitude of the fear response during therapy. there was inconclusive support for the notion that extinction of physiological measures of fear is sufficient. in itself. to bring ahout significant therapeutic change in implosion. Alternative explanations are possible. Borkovec (1972) has suggested that implosion may reduce physiological measures of fear through some traditional learning mechanism, such as extinction. but that therapeutic change in behavioral or subjective measures is more a function of cognitive factors. In the present study. the pattern of physiological arousal was suggestive of an extinction process. but. consistent with Borkovec’s model. neither the pattern nor magnitude of arousal correlated significantly and positively with behavioral or subjective measure of outcome. Leitenberg, et. al. (1969) The
present
Study
marks
(he first
182
CASEHlSTORfES ANI)SHORlZR~OMM~~tCATl~~S
have hypothesized that subjective reports of anxiety may tend to extinguish more slowly than physiological responses. This could explain the fact that group IT manifested little improvement in self-reported fear at outcome despite a significant decrease in heart rate arousal during therapy.
REFERENCES
BORKOVEC T. D. (1972) Effects of expectancy on the outcome of systematic desensitization and implosive treatments for analogue anxiety. B&X. Therap.r 3. 29940. DAVIWN G. C. (196X) Evaluation of the efficacy of the components of reciprocal inhibition psychotherapy. J. ahtion77. PstAoI. 73. 91-99. FAZIO A. (1970) Treatment components in implosive therapy. f. ab~7or17~. Psrcl7of. 76, 71 I-2t9. HO~MXONR. J. and RACHMANS. (1970) An experimental investigation of the implosion technique. Behar. Res. & Therapy 8. 21-27. HOGAN R. A. and KIRCHNI~R J. H. (1967) Preliminary report of the extinction of learned fears via short-term implosive therapy. J. ab~~o~r~l. Ps~~c/70~ 72. 10~109. KIRCHNER J. H. and HOGANR. A. (1966) The therapist variable in the implosion of phobias. Psrcl7oti7e~a~7.r: Tl7eory. Research arid Practice 3. l_OZ-104. LANG P. J. and LAZOVIKA. D. (1963) Experimental desensitization of a phobia. J. ahr1orn7. Psychol. 66. 51%-x%.
LEITENBERG H., AORASW. S. and BARLOWD. H. (1969) Contribution of selective positive reinforcement and therapeutic instructions to systematic desensitization therapy. J. abt~om. Ps)rko/. 74. 113-l 18. STAMPFLT. G. and LI VISD. J. (1967) Essentials of implosive therapy: a learning theory based psychodynamic behavioral therapy. j. ah77onn. Psrchol. 72. 496503. STERN R. and MARKS I. M. (1973) Brief and prolonged flooding: a comparison in agoraphobic patients. Arcl7s Gcrr. Psychiatry* 28, 770-276. WATSONJ. P. and MARKSI. M. (1971) Relevant and irrelevant fear in flooding-a crossover study of phobic patients. Behaar. Therapy 2, 275-293. WOLIY J. (19%) P.~~~~lo~~~‘,~a~~~ by R~,cip~~~u~~/7~1;bir;o~1. Stanford University Press. Stanford. WOLI’I.J. and LANG P. J. (1964) A fear survey schedule for use in behavior therapy. Bc~har. Rcs. & Tfwap) 2. Y-.70.
1975. Vol
13. pp. 177-182. Pergamon Press. Prmted m Great Bntam
CASE HISTORIES
AND SHORTER
COMMUNICATIONS
Implosion therapy by tape-recording (Rrwicctl
3 Juw
1971)
According to the model proposed by Stampfl and Levis (1967).implosion reduces fear by evoking anxiety in the presence of cues associated with the phobic object. but in the absence of primary reinforcement. An essential requirement for rapid therapeutic effect is that the patient be made to experience intense affect. since “the greater the non-reinforced anxiety experienced. the greater the extinction of fear” (Hogan and Kirchner. 1967). Thus. the patient is repeatedly presented with fear-evoking sttmuli and kept at a high level of arousal until ‘a significant diminution in anxiety has resulted (Stampfl and Levis. 1967). Thts model assumes that this ‘significant diminution in anxiety’ is equivalent to extinction of the fear response. Only a handful of studies of implosion. usmg human subjects. have attempted to relate the pattern and magnitude of fear during therapy to outcome measures. Hogan and Kirchner (1967) measured heart rate continuously throughout implosion. Compared to a no-treatment control procedure. implosion generated significantly greater heart rate arousal during therapy and greater behavioral improvement at assessment. suggesting support for the extmction model. In contrast. Watson and Mat% (1971) found no correlation between overt anxiety during flooding and measures of outcome. Stern and Marks (1973) found ‘little skin conductance activity or tachycardia’ during flooding in fantasy. rather than the high level of arousal required by StampR’s model. The present study attempted a partial test of some of the model’s assumptions within the context of an outcome study of implosion therapy by tape recording. Kirchner and Hogan (1966) have claimed that a single, brief session of implosion therapy by tape recording can dramatically reduce phobic avoidance behavior. However. Hodgson and Rachman (1970) and Fazio (1970) failed to replicate these results. Findings from these and other studies of implosion are difficult to interpret because of the absence of objective measures of fear during the therapy session. In the absence of such measures. it is difficult to judge whether the implosive procedures succeeded in creating the pattern of arousal demanded by StampR’s model. Failure to meet the requirements of the model might account for the failures to replicate. The present study included physiological and subjective measures of fear during therapy in an attempt to replicate the Kirchner and Hogan (1966) experiment. using double-blind methodology and a placebo control. It was expected that after exposure to a tape recorded session of implosive therapy, rat phobic subjects would demonstrate significantly greater improvement than controls on a behavioral avoidance test and a questionnaire. In conformity with the extinctton model. it was predicted that the implosion group would manifest greater average fear. as well as a significant reduction in fear. during therapy. and that measures of fear during therapy and at assessment would be correlated. METHOD
The Ss were 24 female undergraduates ioral avoidance test.
selected for rat-phobia
by a fear questionnaire
and a subsequent
behav-
Apparatus Heart rate was monitored with a Grass Model 7 polygraph. electrodes. A stereo tape recorder with a fixed sound intensity
using a cardiotachometer and conventional setting was used to play the tape recordings.
EKG
A modified version of the Fear Survey Schedule (Wolpe and Lang. 1964) was distributed to approximately 750 undergraduates. Only those 61 females who rated their fear of rats as maximal were contacted and asked to volunteer for “an experiment to test a new form of therapy which had proven effective in eliminating fears”. At the first session. El administered a pretreatment behavtoral avoidance test (BTI). following a procedure similar to that of Davison (1968). Ss gave a subjectivje rating on a I-10 scale of their fear at each step of the test. Only those 24 Ss who refused to touch the rat were asked to contmue in the study. Ss filled out a 24-item. truefalse rat questionnaire. which asked how thev reacted to rats m v*arious real-life situations. All scores were coded. and Ss were matched on the basis of behavioral performance and randomly assigned to three groups. 8 Ss per group: implosion therapy (IT). mformational placebo UP). and no-treatment (NT). At the start of the second session, each S was met individually by a female assistant. E2. who attached electrodes and monitored heart rate for I5 min to establish a base rate. At the end of the base rate period. E2 learned the Ss group assignment from a coded card and proceeded with the therapy sessron. 177
178
CASE HISTORIkS
AND
SHORTFR
COMML’UICATIONS
Grou/l IT. This group heard a 39-mm. standardized. tape recorded session modeled after the one developed and Hogan (1966). Ss were told. by way of rationale. that the therapy was based on the prmciple that “the best way to eliminate fear is to face up to it”. It was explained that the tape would Include some terrifying imagery. and Ss were mstructed to allow themselves to experience as much fear as possible. Group IP. This group heard a 39-min. tape recorded informational placebo. which presented factual information about the life habits of rats. read from scientific articles. The contents were selected to be as mnocuous as possible. Ss were told that the therapy was based on the principle that “the best way to eliminate fear is to learn more about the thing you lear.” They were told that the tape vvould provide factual information without arousing fear, and they were instructed to relax as much as possible. Group N7: No tape recording was played. E2 informed this group that “due to a mechanical failure in the polygraph”. there would be a delay before therapy could begin. Heart rate was monitored continuously during therapy, immediately lollowmg which El administered another behavioral test (BTU). on a double blind basis. following the same procedure used in BTI. All Ss then completed the rat questionnaire for the second time. Ss from groups IT and IP also filled out a therapy questionnatre (TQ). This included a self-report rating. on a l-5 scale. of both the average (TQ Average) and maximal (TQ Max) amounts of fear experienced during the therapy session. The TQ also asked for ratings of the clarity of imagery attained during therapy, the amount of faith the S had in the therapy, both before and after treatment. and the amount of pressure the S felt to perform tasks during BTI and BTII. At a follow-up session. about one week later. El repeated the behavioral test (BTIII). by Kirchner
RFSL’LTS
Figure I shows the average number of BT items completed by each group during BTI and BTII. As predicted. group IT changed the most, followed in turn by groups IP and NT. BT change scores (BT-CS) were computed for each S, using the method of Lang and Lazovik (1963):
BT-CS =
number
of items BTII - number number
of items BTI
of items BTI
An analysis of variance, using these changes scores. found no statistically significant diflerences between groups (F = 1.58.4f = Z/21). When scores on BTII and BTHI were compared within each group. no significant change in behavior was found. Figure 2 shows the results on the self-report measure of fear taken during each behavioral test. For a given Sand a given behavioral test. the behavioral test fear score (BTFS) was defined as the sum of verbal fear ratings divided by the number of BT items successfully completed. In computmg BTFS’s for BTII and BTIII. only those ratings from tasks which had been completed during BTI were included. In contrast to the commonly used fear thermometer, this method of scoring controls for differential progress on the behavioral test. As can be seen in Fig. 2. it was group IP, not group IT. that showed the greatest drop in fear on this measure. A behavioral test fear change score (BTF-CS) was computed for each S as follows: BTFS on BTI - BTFS on BTII BTF_CS = ~______..___ BTFS on BTI An analysis of variance. using these change scores. revealed significant group differences. Subsequent comparisons showed significant differences between group IP and each of the other groups. hut no significant differences between groups IT and NT (see Table I).
Fig. I. The average
number
of behavioral test items successfully (BTI) and after (BTII) therapy.
completed
by each group
before
CASE HISTORIES
Fig. 2. The average
Table
Source Between Within Total
subjective
ASD
SHORTER
179
COMML’UKATIOVS
fear reported by each group on a I-IO scale.
I. Analysis of variance for behavioral
during
BTI and BTU. Ratings
test fear change
were
scores
SS
4f
MS
F
P
0.04 I.17 I.57
2 21 23
0.200 0.056
3.57
0.05
Duncan Multiple Range Test: Treatment totals: Group NT = 2.44: Group IT = 2.54: Group Observed values: IP vs NT: 2.24, 11 < 0.05: IT vs NT: 0.10: IP vs IT: 1.14. ,’ < 0.05. There were no significant differences between groups from BTI to BTII (F = 0.80. df = 2 ?O).
in terms of the amount
Both the TQ Average and the TQ Max scores indicated significantly in group IT than in group IP (TQ Average: I = 5.18. [lf = 14. p < 0.01: In order to obtain average scores. heart rate was computed at I-min period and throughout therapy. As expected. group IT showed an overall a fall in average heart rate between base and therapy periods (see Fig. 3). computed for each S as follows: average HR_CS = __L__
therapv
h.r. - average
average
IP = 4.6X.
of change on the rat questionnaire
greater subjective fear during therapy TQ Max: t = 5.97. dJ= 14. P < 0.01). intervals during the last 5 min of baserise. while groups IP and NT showed Heart rate change scores (HR-CS) were base h.r.
base h.r.
An analysis of variance revealed significant differences between group IT and each of the other groups. but no significant differences between groups IP and NT (see Table 2). These results support the contention that implosion produced significantly greater fear arousal than either placebo or no-treatment procedures. For implosion and placebo Ss. the TQ Average score correlated significantly with the HR-CS measure (r = 0.56). indicating that Ss reporting the greatest average fear during therap! demonstrated the greatest increase in heart rate between base and therapy periods. To determine the pattern of heart rate arousal during therapy Itself. heart rate was averaged into 5-min blocks oftime during the first 25 min oftherapy and durmg minutes 34 through 3X at the end. The graph in Fig. 4 shows the predicted pattern ofarousal. with group IT rising to a plateau within the first 10 min. stabilizing at this level, and then falling towards base levels. Compared with group IP. group IT showed significantly higher peaks of arousal during minutes l-25 of therapy (t = 2.87. L!/‘= 14. p < 0.025). Within group IT. the fall in heart rate from the highest level during minutes l--25 to the average level during mmutes 34-3X was statistically signiiicant Table 2. Analysis Source Between Within Total
of variance
for heart rate change
scores
ss
o/
MS
F
P
0.096 0. I 7 I 0.267
2
0.048
6.00
0.01
21
0.00x
23
DuncanMultipleRangeTest:Treatment totals: Group NT = -0.358:Group IT = +0.81X;Group Observed values: IP vs NT: 0.256: IT vs NT: 1.176. p < 0.01: IP vs IT: 0.920. p c; 0.05.
IP = -0.102.
180
CASE HISTORIES
ANI)
SHOHTEK
76L
Base-period
COMMLNICATIONS
Therapy-period
Fig. 3. Computations of heart rate were made at l-mm intervals during the last 5 min of baseperiod and throughout therapy in order to arrive at the average heart rate of each group durmg base and therapy periods. (t = 2.45. df= 7, p < 0.05). A similar analysis within group IP failed to achieve significance (r = 1.10. &= 7). There were no significant differences between the average heart rate scores of groups _ . IT and IP during minutes 34-38 (I = 1.35. $= 14). Thus, although the groups differed in maximal heart rate arousal during the first half of therapy, no significant difference remained at the end of the session. The pattern of significant arousal followed by significant decline shown by the implosion group conformed to the requirements of the extinction model proposed by Stampfl and Levis ( 1967).
Fig. 4. In order to demonstrate the heart rate pattern during therapy. heart rate was averaged into 5-mitt blocks of time.
Correlations were computed between measures of fear during therapy and the two behavioral-test measures of outcome. As shown in Table 3. the only statisttcally significant result was a negative correlation of I’ = -0.58 between the two self-report measures of fear. the TQ Average and the BTF-CS. indicating that Ss reporting the greatest average fear during therapy tended to report the lrusr improvement at assessment. In a separate computation. a correlation of r = 0.66 was found between the HR-CS and the fall in heart rate from peak to final levels within group IT. This relationship was significant at p < 0.05 if considered as 3 one-tail test of an a priori hypothesis. An analogous computation within group IP did not approach significance. Table 3. Correlations between measures of fear during therapy and fear at outcome
TQ Average
Outcome BT-CS BT-FCS
* p < 0.01.
Fear during therapy Heart rate change scores
Fall in heart rate from peak to final levels
IT
IT + IP
IT
IT+ IP
+ 0.20
- 0. I I
- 0.02
+0.36
-05X’
+ 0.52
- 0.04
+0.36
+0.18 to.14
IT
IT f IP
+ 0.32 - 0.56
CASE
HISTORIES
AND
SHORTER
COMMUNICATIONS
181
When groups IT and IP were compared on the remaining questions from the therapy questionnaire. no significant differences were found.
DISCUSSION
experimen~l demonstration with human SS that a session of implosion therapy can produce the pattern of fear arousal described by Stampff’s model. Tape recorded imPkxion ewxated Significantly greater fear arousal than control procedures. and implosion SS showed the predicted pattern of heart rate change during therapy. However, the results did not support the claims of Kirchner and Hogan (1966) that a single. brief session of implosion therapy by tape recording is a particularly effective treatment. The prediction that the imP1osion group would show significantly greater therapeutic change than placebo or controls was not confirmed. These findings are in accord with the failures to replicate reported by Fazio (1970). and Hodgson and Rachman (1970). It is noteworthy that Hodgson and Rachman’s implosion group demonstrated slightly greater improvement over controls as measured by behavioral performance but poorer improvement as measured by self-report, precisely the pattern shown by the implosion and placebo groups in this study. Some limitations of the present study bear comment. For one thing. the implosion session tasted only 39 min. It has been reported that longer durations are generally more effective (Stern and Marks 1973). Also, this study included only one session of implosion. whereas clinicians routinely administer multiple sessions. Another limitation was that therapy was conducted by tape recording rather than in person. Tape recordings have generally been found to be less effective than a live therapist (Stern and Marks. 1973). Although necessary in order to replicate Kirchner and Hogan’s procedure, these limitations may, in part. account for the disappointing outcome. Hogan and Kirchner (1967)contended that “the greater the nonreinforced anxiety experienced. the greater the extinction of the fear’.. A modest, but statistically nonsignificant. correlation of 0.52 within the implosion group suggested a possible relationship between a rise in heart rate from base to therapy levels, on the one hand, and a decline in self-reported fear on the behavioral test. on the other. With a larger sample. a significant relationship might have emerged. Somewhat stronger support was provided by the finding of a significant 0.66 correlation within group IT between a rise in average heart rate from base to therapy levels and a fall in heart rate during therapy from peak to final levels. However, Hogan and Kirchner’s hypothesis failed to account for many of the findings regarding behavioral and subjective measures of fear. Although group IT showed an overall pattern of fear arousal in conformity with the extinction model. implosion subjects did not demonstrate significantly greater improvement at outcome as measured by behavioral performance or self report. Also. there was evidence that Ss reporting the greatest fear during therapy tended to report the least improvement at outcome. This latter finding. seemingly a direct contradiction of Hogan and Kirchner’s predictions. implies that some Ss may have been adversely affected by intensive fear arousal. This is reminiscent of the clinical report by Wolpe (1958) that_ in desensitization. “a stimulus that is too strong may actually increase sensitivity”. a process he calls ‘sensitization’. It is possible that ‘sensitization” may underlie some of the reported failures to achieve therapeutic success using implosive techniques, especially in briefer courses of therapy. Stampfl and Levis (1967) emphasize the importance of continuing the implosive process until “a significant diminution in anxiety has resulted”. In the present research. only group IT showed a significant diminution in heart rate during therapy; but it did not show signifi~ntly greater improvement than controls at assessment. in addition. there was no significant correlation within group IT between the fall in heart rate during therapy and any of the outcome measures. Space does not permit adequate discussion of whether the decline m heart rate seen during the implosive session is best designated ‘habituation’ or ‘extinction’. However. tt should be noted that. within the context of StampR’s writings. a diminution in fear arousal. even within a single session. is tantamount to ‘extinction’: “At each stage of the process an attempt is made by the therapist to attain a maximal level of anxiety evocation from the patient. When a high level of anxiety is achieved. the patient is held on this level until some sign of spontaneous reduction in the anxiety-inducing value of the cues appears (extinctionr (Stampfl and Levis. 1967). Although the present research indicated that Stampfl’s model correctly described the pattern and magnitude of the fear response during therapy. there was inconclusive support for the notion that extinction of physiological measures of fear is sufficient. in itself. to bring ahout significant therapeutic change in implosion. Alternative explanations are possible. Borkovec (1972) has suggested that implosion may reduce physiological measures of fear through some traditional learning mechanism, such as extinction. but that therapeutic change in behavioral or subjective measures is more a function of cognitive factors. In the present study. the pattern of physiological arousal was suggestive of an extinction process. but. consistent with Borkovec’s model. neither the pattern nor magnitude of arousal correlated significantly and positively with behavioral or subjective measure of outcome. Leitenberg, et. al. (1969) The
present
Study
marks
(he first
182
CASEHlSTORfES ANI)SHORlZR~OMM~~tCATl~~S
have hypothesized that subjective reports of anxiety may tend to extinguish more slowly than physiological responses. This could explain the fact that group IT manifested little improvement in self-reported fear at outcome despite a significant decrease in heart rate arousal during therapy.
REFERENCES
BORKOVEC T. D. (1972) Effects of expectancy on the outcome of systematic desensitization and implosive treatments for analogue anxiety. B&X. Therap.r 3. 29940. DAVIWN G. C. (196X) Evaluation of the efficacy of the components of reciprocal inhibition psychotherapy. J. ahtion77. PstAoI. 73. 91-99. FAZIO A. (1970) Treatment components in implosive therapy. f. ab~7or17~. Psrcl7of. 76, 71 I-2t9. HO~MXONR. J. and RACHMANS. (1970) An experimental investigation of the implosion technique. Behar. Res. & Therapy 8. 21-27. HOGAN R. A. and KIRCHNI~R J. H. (1967) Preliminary report of the extinction of learned fears via short-term implosive therapy. J. ab~~o~r~l. Ps~~c/70~ 72. 10~109. KIRCHNER J. H. and HOGANR. A. (1966) The therapist variable in the implosion of phobias. Psrcl7oti7e~a~7.r: Tl7eory. Research arid Practice 3. l_OZ-104. LANG P. J. and LAZOVIKA. D. (1963) Experimental desensitization of a phobia. J. ahr1orn7. Psychol. 66. 51%-x%.
LEITENBERG H., AORASW. S. and BARLOWD. H. (1969) Contribution of selective positive reinforcement and therapeutic instructions to systematic desensitization therapy. J. abt~om. Ps)rko/. 74. 113-l 18. STAMPFLT. G. and LI VISD. J. (1967) Essentials of implosive therapy: a learning theory based psychodynamic behavioral therapy. j. ah77onn. Psrchol. 72. 496503. STERN R. and MARKS I. M. (1973) Brief and prolonged flooding: a comparison in agoraphobic patients. Arcl7s Gcrr. Psychiatry* 28, 770-276. WATSONJ. P. and MARKSI. M. (1971) Relevant and irrelevant fear in flooding-a crossover study of phobic patients. Behaar. Therapy 2, 275-293. WOLIY J. (19%) P.~~~~lo~~~‘,~a~~~ by R~,cip~~~u~~/7~1;bir;o~1. Stanford University Press. Stanford. WOLI’I.J. and LANG P. J. (1964) A fear survey schedule for use in behavior therapy. Bc~har. Rcs. & Tfwap) 2. Y-.70.