Moderating Effects of Contextual Variables on the ... - PsycNET

Journal of Abnormal Psychology 1984 Vol 93, No 3 285-294

Copyright 1984 bv Ihc American Psychological Association, Inc

Moderating Effects of Contextual Variables on the Relationship Between Hypnotic Susceptibility and Suggested Analgesia Nicholas P. Spanos, Sharon Kelly Kennedy, and Maxwell I. Gwynn Carleton University Subjects high, medium, and low on hypnotic susceptibility were assessed on the cold pressor task before and after one of three instructional treatments The treatments were (a) brief instructions to try to reduce pain (n = 30), (b) the same analgesia instructions preceded by a hypnotic induction procedure (n = 30), (c) no hypnotic induction, no instructions (control, n - 15). In the hypnotic treatment, susceptibility correlated significantly with reductions in reported pain, and highsusceptible subjects reported significantly larger pain reductions than did control subjects. In the instruction-alone treatment there was no significant relationship between susceptibility and pain reduction, and subjects at all three susceptibility levels reduced reported pain significantly more than did control subjects and as much as did high-susceptible hypnotic subjects. These findings indicate that the correlation between hypnotic susceptibility and hypnotic analgesia is moderated by subjects' attitudes and expectancies concerning their own performance in situations denned as related to hypnosis

A number of studies have found that hyp- able to all subjects, but is a relatively ineffective notic and nonhypnotic subjects administered means of reducing pain The second, and much suggestions for analgesia report reductions m more effective component of suggested analpain of equivalent magnitude (Barber & Hahn, gesia, involves the separation (dissociation) of 1962; Evans & Paul, 1970; Spanos, Barber, & pain from phenomenal awareness. DissociaLang, 1974; Spanos, Radtke-Bodorik, Fergu- tion, however, is only available to subjects who son, & Jones, 1979). Several studies also found are relatively high m hypnotic susceptibility. that the degree of suggestion-induced pain re- Low-susceptible subjects lack the ability to duction (suggested analgesia) correlated sig- dissociate Thus, from Hilgard's (1977) pernificantly with pretested levels of hypnotic spective, the correlation between hypnotic susceptibility (Evans & Paul, 1970; Hilgard & susceptibility and suggested analgesia occurs Hilgard, 1975; Spanos etal., 1979) Moreover, because high-susceptible subjects dissociate the magnitude of the correlation between sus- during analgesia testing and thereby experience ceptibility and suggested analgesia was about large pain reductions, whereas low-susceptible the same for hypnotic and nonhypnotic sub- subjects are unable to dissociate and thereby jects (Evans & Paul, 1970; Spanos et al., 1979). experience only the small pain reductions proDespite their consistency, the interpretation of duced by attention diversion and relaxation. these findings remains a controversial issue Hilgard (1977) further contends that high-susOne influential account, proffered by Hilgard ceptible subjects given suggestions of any kind (1977) holds that suggested analgesia involves have a tendency to "drift into hypnosis" (p. two components, the first component consists 51) and undergo dissociation even in the abof attention diversion and relaxation Accord- sence of a formal hypnotic induction proceing to Hilgard (1977), this component is avail- dure Thus, the finding that analgesia suggestions are equally effective with and without a prior hypnotic procedure is explained by arguing that the high-susceptible subjects in both This research was supported by a grant from the Medical of these treatments become "hypnotized" (i.e., undergo dissociation), whereas the low-susResearch Council of Canada to the first author Requests for reprints should be sent to Nicholas P Spa- ceptible subjects in neither treatment dissociate nos, Department of Psychology, Carleton University, Ot- (Hilgard, 1977) tawa, Ontario, Canada K1S 5B6

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A number of recentfindingsare inconsistent with this dissociation account. For instance, two studies (Farthing, Venturino, & Brown, 1982; Spanos, McNeil, Gwynn, & Stam, 1984) found that low-susceptible subjects given a taxing attention-diversion task (shadowing words) reduced reported pain to the same degree as did high-susceptible subjects given an analgesia suggestion. These results contradict the notion that dissociation (purportedly operative in the high-susceptible subjects) is more effective than is attention diversion in low-susceptible subjects. Along related lines, Spanos, Ollerhead, and Gwynn (1983) found that a hypnotic suggestion for analgesia, a nonhypnotic stress-mnoculation treatment that provided a range of pain-reducing strategies, and brief, nonhypnotic instruction to "do whatever you can to reduce pain," were equally effective in reducing reported pain and in enhancing pain tolerance However, although the correlation between pretested susceptibility and extent of pain reduction was high and statistically significant in the hypnotic-suggestion treatment, it failed to approach significance in either the stress innoculation or do-whatever treatments. Finally, Spanos, Hodgms, Stam, and Gwynn (1984) tested subjects for suggested analgesia either before or after they had been assessed on hypnotic susceptibility. As in earlier studies, susceptibility and extent of pain reduction were significantly correlated when susceptibility was assessed before pain testing. However, the correlation between these variables was nonsignificant when the assessment of susceptibility followed pain testing. Taken together, these findings indicate that large reductions in reported pain are not restricted to subjects high in hypnotic susceptibility, and that the often-replicated correlation between susceptibility and extent of instruction-induced pain reduction is more situation specific than dissociation theory indicates. For instance, dissociation theory does not account for why susceptibility and degree of suggestioninduced pain reduction correlated significantly only when the assessment of susceptibility preceded pain testing (Spanos, Hodgms, Stam, & Gwynn, 1984), or why pretested susceptibility and degree of pain reduction correlated significantly when nonhypnotic subjects were given traditionally worded analgesia suggestions (Evans & Paul, 1970), but not when such

subjects were given stress innoculation or dowhatever instructions (Spanos, Ollerhead, & Gwynn, 1983). Spanos, Ollerhead, and Gwynn (1983) suggested that these findings are consistent with a cognitive-social psychological account of instruction-induced pain reductions. According to this perspective, instruction-induced pain reductions result, in large degree, from attention diversion, and the ability to divert attention away from noxious stimulation is unrelated to hypnotic susceptibility. On the other hand, the degree to which experimental subjects divert attention away from noxious stimulation is highly dependent on then" interpretations of the test situation. These interpretations are, in turn, influenced by subjects' preconceptions of and attitudes toward their own hypnotic susceptibility, and by the degree of similarity in the hypnotic susceptibility test situation and in the suggested analgesia test situation (Spanos, Hodgins, Stam, & Gwynn, 1984; Spanos, McNeil, Gwynn, & Stam, 1984). Hypnotic susceptibility is measured in terms of success at responding to a standardized series of test suggestions, and test suggestions typically invite subjects to become absorbed in imagining specific situations (e.g., imagine a cast on your arm that keeps the elbow from bending). Numerous studies (reviewed by Spanos, 1982) indicate that the tendency to become absorbed in suggestion-related imaginings is correlated with response to hypnotic test suggestions. Analgesia suggestions, like standardized susceptibility test suggestions, invite subjects to become absorbed in imaginary situations (e.g., imagine novacaine being injected into your hand). Thus, high-susceptible subjects may be more proficient than are low-susceptible subjects at suggested analgesia, because the high susceptibles are better able than are the low susceptibles to carry out the imaginings suggested. By explicitly instructing subjects to imagine specific events, these suggestions may contain an implicit injunction against using nommaginal attention-diversion strategies for pain reduction (Spanos, Hodgins, et al., 1984). Such an injunction would, of course, be much more detrimental to the performance of the low-susceptible subjects than to that of high-susceptible subjects. A second reason for the usual superiority

MODERATING EFFECTS ON SUGGESTED ANALGESIA

of high-susceptible subjects at suggested analgesia may stem from a carryover of expectancies and attitudes from the hypnotic susceptibility testing situation to the pain testing situation. Low-susceptible subjects are likely to define themselves as being either unwilling or unable to respond to hypnosis and suggestion. In fact, low-susceptible subjects sometimes appear to purposely behave in a counterdemand fashion to convey the impression that they are not gullible and cannot be hypnotized (Jones & Spanos, 1982). Thus, low-susceptible subjects who connect the analgesia test situation with their prior hypnotic susceptibility testing are likely to develop negative attitudes and expectancies concerning their response to analgesia testing. As a result, they are unlikely to initiate and sustain the cognitive coping strategies required to reduce pain, even when the wording of the analgesia suggestion does not limit them to the use of imagery-based coping strategies. According to these ideas, the correlation between susceptibility and suggested analgesia attains significance when the two testing situations show much overlap and tend to be interpreted by subjects as being related (e.g., both situations are defined as involving hypnosis, both call for the same imagmal abilities) The relationship between these variables tends to break down when the two testing situations are disparate (e.g., analgesia testing is not implicitly or explicitly defined as related to hypnosis, subjects are encouraged to use nonimaginal coping strategies). The present study tested these ideas by using subjects who had been previously assessed on hypnotic susceptibility. Three groups of subjects were exposed to noxious stimulation (hand immersion in ice water) on a baseline and again on a posttest trial. Those in one group were control subjects who received the posttest without intervening treatment instructions Subjects in the remaining two groups were given instructions that encouraged them to do everything they could to reduce their pain. Unlike conventional analgesia suggestions, these instructions did not restrict subjects to using an imagery-based coping strategy. In fact, the instructions did not specify a strategy of any kind. Instead, they indicated that subjects should do anything and everything they could to reduce pain, and informed

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them that other subjects had been successful in reducing pain when they tried their best to do so. Subjects in one treatment group received these analgesia instructions without preliminaries, whereas those in the other treatment were administered a hypnotic induction procedure before the analgesia instructions. We predicted that high-, medium-, and low-susceptible subjects in the instruction-alone treatment and high-susceptible subjects in the hypnotic treatment would report significantly greater pam reductions than would control subjects. We also predicted that the correlation between pretested susceptibility and pain reduction would be nonsignificant in the instruction-alone treatment, but relatively high and significant in the hypnosis-plus-instruction treatment. Our rationale for these predictions was as follows. Low-susceptible subjects see themselves as unresponsive to hypnotic procedures. Defining analgesia instructions as part of a hypnotic procedure inhibits the performance of these subjects because they tend to interpret the pain reduction task as one that they are unable or unwilling to perform optimally. For high-susceptible subjects, defining the analgesia situation as hypnosis is congruent (rather than incongruent) with expectations for optimal performance. Therefore, these subjects tend to follow the analgesia instructions and devise successful pain-reducing strategies. Thus, the divergent attitudes and expectations concerning hypnosis held by high- and low-susceptible subjects leads to a substantial relationship between pretested susceptibility and degree of instruction-induced analgesia. Our analgesia instructions did not closely resemble conventionally worded hypnotic test suggestions. Therefore we anticipated that subjects who did not receive a hypnotic induction procedure would not see the requirements of the analgesia task as strongly related to their previous susceptibility test performance. More specifically, we hypothesized that low-susceptible subjects given instructions alone would not connect their negative attitudes and expectations about hypnosis with the analgesia test situation. Instead, they, like the high-susceptible subjects in both the hypnotic and instruction-alone treatments, would be motivated to devise successful cognitive strategies for reducing pain. Thus, we predicted

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that low-susceptible subjects given instructions alone would report (a) significantly greater pain reductions than did low-susceptible subjects given hypnosis plus instruction and (b) pain reductions as large as those reported by the high-susceptible subjects in the two instruction treatments. A number of studies (Chaves & Barber, 1974; Spanos, Brown, Jones, & Horner, 1981; Spanos, Hodgins, Stam, & Gwynn, 1984; Spanos, McNeil, Gwynn, & Stam, 1984; Spanos, Stam, & Brazil, 1981) have found a significant correlation between degree of instruction-induced pain reduction and the extent to which subjects report the use of coping cognitions (e.g., pleasant imagery, nonimaginal self-distraction). Therefore, we anticipated that decreases in reported pain would be accompanied by reports of increased cognitive copmg.

McNeil, Gwynn, and Stam (1984) The first asked them to rate the extent of time, on the immediately preceding immersion, that they had focused on the pain and had thought about the noxious aspects of the situation Scale alternatives ranged from not at all (5) to all the time (1) The second questionnaire asked subjects to rate the extent of time on the preceding immersion that they thought about or imagined things that were unrelated to or inconsistent with the pain On this scale not at all was scored 1 and all the time was scored 5. For each immersion, scores on the first questionnaire were multiplied with scores on the second to yield an overall coping score Thus, each subject received two coping scores, one for the baseline trial and one for the posttest Within the three susceptibility levels, subjects were assigned at random to three groups with the restriction that half as many high-, medium-, and low-susceptible subjects were assigned to the control group as to each of the experimental treatments Thus, the control group contained 5 high-, 5 medium-, and 5 low-susceptible subjects, whereas each experimental treatment contained 10 subjects at each susceptibility level Chi-square analyses indicated no significant difference in the ratio of males to females among any of the treatment groups

Method Subjects

Experimental Treatments

A total of 43 male and 32 female Carleton University undergraduates (ages 18-28) who had previously been administered the Carleton University Responsiveness to Suggestion Scale (CURSS, Spanos, Radtke, Hodgins, Stam, & Bertrand, 1983) in groups of 5 to 10 individuals, volunteered to participate in a study that involved pain All received course credit for their participation One third of these subjects (n = 25) had obtained low scores (0-2), one third had obtained medium scores (3-4), and one third had obtained high scores (5-7) on the objective dimension of the Carleton Scale (CURSS O)

Subjects assigned to the hypnosis-plus-instruction treatment were orally administered a 10-rmn hypnotic induction procedure modified from Barber (1969) Immediately following the induction they were administered the following analgesia instructions

Apparatus, Pain Ratings, and Coping Ratings A styrofoam tank measuring 35 4 cm X 35 6 cm X 38 1 cm held the ice and water used as the cold pressor stimulus A wire-mesh screen divided the tank into a section containing crushed ice and another containing ice-free water The water was maintained at a temperature ranging between 0 °C and 2 °C and was circulated during each immersion All of the subjects immersed an arm (left and right were counterbalanced) m the ice water for 60 s on two occasions (baseline trial and posttest trial) Before the baseline trial, subjects were instructed in the use of a rating scale taken verbatim from Spanos and Hewitt (1980), with numbers that ranged from no pain (0) to the most severe pain ever experienced (20) Subjects were instructed to call out the scale value that best reflected their pain level whenever the experimenter said the word report They were signaled to report twice on each trial, once at 30 s and again at 60 s of immersion (immediately before removing the hand) All of the subjects were tested individually by the same female experimenter. Following their baseline trial and again following their posttest trial, subjects were administered two questionnaires taken verbatim from Spanos,

For this immersion (now that you are deeply hypnotized) please do everything you possibly can to reduce your pain as much as possible Other studies have shown that people (who are hypnotized and) who try to the very best of their ability are successful in reducing their pain significantly (Now that you are hypnotized) it is very important that you do whatever you can to reduce pain as much as possible on your next immersion Following their baseline trial and without further preliminaries, subjects in the instruction-alone treatment were given the above analgesia instructions with the phrases m parentheses omitted Control subjects were posttested without intervening instructions. During posttesting, subjects in all treatments immersed the arm opposite to the one used during baseline testing In all other respects, baseline and posttest procedures were the same

Results Pain Rating A 3 X 3 X 2 (Hypnosis/Instruction Alone/ Control X Susceptibility X 30/60-s Report Intervals) mixed analysis of variance (ANOVA) was conducted on subjects' baseline pain ratings. Neither the main effect for treatments, F(2, 66) < 1, nor the main effect for susceptibility, F(2, 66) = 1.32, p > .10, approached significance. The interactions between treat-

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MODERATING EFFECTS ON SUGGESTED ANALGESIA

ment and susceptibility, F{4, 64) < 1; treatment and 30/60, F(l, 66) = 1.08, p > .10; susceptibility and 30/60, F{2,66) < 1; and the three-way interaction, F(4, 66) = 1.02, p > .10, also failed to approach significance. Thus, subjects at all susceptibility levels and in all treatments reported equivalent levels of baseline pam. Subjects' 30-s and 60-s baseline pam ratings were subtracted from their corresponding posttest pain ratings to yield a 30-s and a 60-s pain-rating difference score for each subject. Thus, negative difference scores indicated a decrease in pain from baseline to posttest, whereas positive difference scores indicated an increase in pain. The effects of the three treatment groups and susceptibility on pain-report difference scores were analyzed initially with an overall 3 X 3 X 2 (Hypnosis/Instruction Alone/Control X Susceptibility X 30/60-s) mixed ANOVA. The Treatments X Susceptibility interaction was highly significant, F(4, 66) = 5.39, p < .001, and more specific ANOVAS were employed to localize the significant effects in terms of our a priori predictions. Instructional treatments and susceptibility Our predictions concerning the interaction of treatment instructions and susceptibility were assessed by conducting a 2 X 3 X 2 (Hypnosis/ Instruction Alone X Susceptibility X 30/60-s Report Intervals) mixed ANOVA on pam-rating difference scores. Hypnosis/instruction alone and susceptibility were between-subjects variables and 30/60 s was a within-subjects variable. Significant main effects were found for treatments, F(l, 54) = 10.35, p < .001, and susceptibility, F(2, 54) = 15.36, p < .001. As predicted, however, both of these effects were qualified by a significant Treatments X Susceptibility interaction, F(2, 54) = 10.22, p < .001. No other effects attained significance, and the means for the significant interaction are shown in Table 1. Tukey's post hoc comparisons confirmed the following predictions: (a) Within the hypnosis-plus-instruction treatment, pain-rating decreases were related to susceptibility. More specifically, in this treatment high-susceptible subjects reported significantly larger pain reductions than did medium-susceptible subjects who, in turn, reported significantly larger pain reductions than did low-susceptible subjects, (b) Within the instruction-alone treatment

there were no significant differences in degree of reported pam reduction between susceptibility groups, (c) High-susceptible subjects in the hypnosis treatment failed to differ significantly in degree of pain reduction from either high-, medium-, or low-susceptible subjects in the instruction-alone treatment, (d) Low-susceptible subjects given instruction-alone reported significantly larger pain reductions than did low-susceptible subjects given hypnosis plus instruction. Instructional treatments versus control A 3 X 2 (Susceptibility X 30/60 s) mixed ANOVA on the pain-rating difference scores of control subjects found no significant main effect for susceptibility and no significant interaction. Therefore, within this group, subjects at different susceptibility levels were combined to form a single control group with n = 15. Painrating difference scores for each of the six groups shown in Table 1 were compared to the pain-rating difference scores of control Table 1 Baseline, Posttest, and Difference Pain-Rating Scores for High-, Medium- and Low-Susceptible Subjects in Hypnosis and Instruction-Alone Treatments Susceptibility Condition

Low

Medium

High

Hypnosis Baseline M SD Posttest

11 15 4.01

1150 4.19

12.30 3.15

M SD

11.45 3.17

9.60 4.85

}£$* • 3$>r

Difference

M SD

0 30c 200

-190b 194

- 4 75. 1.59

Instruction alone Baseline M SD Posttest

1130 2 80

11.50 3.37

11 15 2.87

M SD

7 65 3 20

8 80 2 77

7.05 2.24

- 3 65. 1.60

- 2 70. 178

- 4 10. 2 13

Difference

M SD

Note For difference scores, within-columns means sharing a common subscript fail to differ significantly at a = .05.

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Table 2 Number of Subjects m Each Treatment Reporting Pain Reductions of at Least 50%, 33%, 20%, 10%, 1%, or Reporting No Reduction Hypnosis anc1 instruction

Instruction alone Pain

High

Low

Medium

Low

Medium

High

Control Collapsed

reduction (%)

n

%

n

%

n

%

n

%

n

%

n

%

n

%

>50 >33 >20 >10 >1 s;0

3 8 9 9 9

30 80 90 90 90 10

0 3 7 10 10 0

0 30 70 100 100 0

1 7 9 9 10 0

10 70 90 90 100 0

1 7 9 10 10 0

10 70 90 100 100 0

1 2 5 6 7 3

10 20 50 60 70 30

0 0

0 0 10 20 20 80

1

2 3 4 8 7

7 13 20 27 53 47

N

1

10

]10

10

subjects with separate 2 X 2 (Treatment/Control X 30/60 s Report Intervals) mixed ANOVAS. Five of these six analyses yielded a significant main effect for the treatment/control variable. Control subjects (M = - . 9 3 , SD = 2.55) reported smaller pain reductions than did highsusceptible subjects, F{\, 23) = 31.39, p < .001; medium-susceptible subjects, ^ 1 , 2 3 ) = 7.00, p < .05; and low-susceptible subjects, F{1, 23) = 16.43, p < .001, in the instructionalone treatment. Control subjects also reported significantly smaller pain reductions than did high-susceptible subjects, F(l, 23) = 32.98, p< .001, and medium-susceptible subjects F(l, 23) = 5.26, p < .05, in the hypnosis-plusinstruction treatment. However, there was no significant difference in pain decrement between control subjects and low-susceptible subjects in the hypnosis-plus-instruction group, PX1, 23) < 1. The Treatment/Control X 30/60 s Report Interval interaction did not attain statistical significance m any of these 2 X 2 ANOVAS. Percentage pain reductions. The percentage that each subject reduced reported pain from baseline to posttest (averaged across 30- and 60-s intervals) was calculated, and the number of subjects in each group who reported reductions of at least 50%, 33%, 20%, and 1% is shown in Table 2. This table clearly indicates that large reductions in reported pain were not restricted to high-susceptible subjects. In fact, just as many low-susceptible instructionalone subjects as high-susceptible hypnotic subjects reported reductions of at least 50%, 33%, and 20%. This table also shows that low-

10

110

1

2 2 8 10

15

susceptible hypnotic subjects were much more likely to report no pain reduction than were low-susceptible subjects given instruction alone, x 2 ( l , N= 10) = 13.33, p < .001. Coping Scores A 3 X 3 (Hypnosis/Instruction Alone/Control X Susceptibility) completely betweensubjects ANOVA on subjects' baseline coping scores yielded no significant main effect for either treatments, F(2, 66) < 1, or susceptibility, F(2, 66) < 1. The Treatment X Susceptibility interaction was also nonsignificant, F(4, 66) < 1. Thus, subjects in all groups reported equivalent levels of baseline coping. Subjects' baseline coping ratings were subtracted from their posttest coping rating to yield a coping difference score for each subject. Positive scores indicated increased coping from baseline to posttest, and negative scores indicated decreased coping. Instructional treatments and susceptibility A 2 X 3 (Hypnosis/Instruction Alone X Susceptibility) completely between-subjects ANOVA on coping-difference scores yielded a significant main effect for treatments, F(l, 54) = 9.56, p < .01. However, this effect was qualified by the Treatments X Susceptibility interaction, which bordered on significance, F(2, 54) = 3.16,/? < .06. The means involved in this interaction are shown in Table 3. Post hoc comparisons indicated that, m the hypnosis treatment, high-susceptible subjects reported greater increments in coping than did either medium- or low-susceptible subjects. In

MODERATING EFFECTS ON SUGGESTED ANALGESIA

the instruction-alone treatment, however, the three susceptibility groups did not differ significantly in degree of coping increment. Moreover, the coping increments reported by high-, medium-, and low-susceptible subjects in the instruction-alone treatments did not differ significantly from the coping increments reported by high-susceptible hypnotic subjects, but were all significantly larger than were the coping increments reported by low-susceptible hypnotic subjects. Instructional treatments versus control Coping-score increments for each of the six groups shown in Table 3 were compared to the coping-score increments of control subjects (collapsed across susceptibility level) with separate F tests. Four of these six analyses yielded significance. Control subjects (M = 3.53, SD = 5.67) reported significantly smaller increments in coping than did high-susceptible subjects, F( 1,23) = 13.68, p < .01; medium susceptible subjects, F(l, 23) = 6.11, p < .05; or low-

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susceptible subjects, F[l, 23) = 5.25, p < .05, in the instruction-alone group. Control subjects also reported significantly smaller coping increments than did the high-susceptible subjects in the hypnosis treatment, F(l, 23) = 13.07, p < .01. However, the coping increments reported by control subjects did not differ significantly from the coping increments reported by medium-susceptible or low-susceptible subjects in the hypnosis treatment. Discussion

As m numerous earlier studies (Evans & Paul, 1970; Hilgard & Hilgard, 1975; Spanos et al., 1979; Spanos, Stam, & Brazil, 1981), we found a significant correlation between hypnotic susceptibility and instruction-induced pain reductions in hypnotic subjects. High-susceptible hypnotic subjects reduced reported pain to a greater degree than did medium- or low-susceptible hypnotic subjects, and to a greater degree than did no-treatment control subjects. Low-susceptible hypnotic subjects did not differ significantly from noTable 3 treatment control subjects in extent of reported Coping Ratings Baseline. Posttest, and pain reduction. It is important that a very Difference Scores for High-, Medium-, and different pattern offindingsemerged for subLow-Susceptible Subjects in Hypnosis jects given the analgesia instructions in the and Instruction-Alone Conditions absence of a prior hypnotic induction. In this case, there was no significant relationship beSusceptibility tween susceptibility level and degree of pain Low Medium High Condition reduction. Instead, low-susceptible, mediumsusceptible, and high-susceptible instructionHypnosis alone subjects all reported significantly larger Baseline pain reductions than did control subjects. 8.30 6.20 M 8.70 Moreover, low-susceptible subjects given the 6.52 5.23 5.27 SD instruction-alone treatment reported signifiPosttest M 10 60 9.30 18 30 cantly larger pain reductions than did lowsusceptible subjects given hypnotic induction, SD 6.77 4.97 5.48 Difference and as much pain reduction as the high-sus100b M 1.90b 12 10. ceptible subjects in both the hypnotic and inSD 4.82 8 74 6 01 struction-alone treatments. Instruction alone The success of our low-susceptible, instruction-alone subjects in attaining relatively high Baseline 6 90 5.90 M 5.20 reductions in reported pain is consistent with 3.52 4.43 2 73 SD recentfindings(Farthing et al., 1982; Spanos, Posttest McNeil, Gwynn, & Stam, 1984), demonstratM 13.60 15 50 17.40 ing that low-susceptible subjects who practiced SD 5.48 5.17 6 15 a taxing attention-diversion procedure during Difference 8.40. 8 60. 1150. noxious stimulation reduced reported pain to M SD 4.38 381 4 60 the same extent as did high-susceptible subjects who were given an analgesia suggestion. On Note Within the difference score columns, means sharing a common subscript fail to differ significantly at a = .05 the other hand, ourfindings,along with those

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N SPANOS, S. KENNEDY, AND M GWYNN

of Farthing et al. (1982) and Spanos, McNeil, Gwynn, & Stam (1984) clearly contradict Hilgard's (1977) assertion that low-susceptible subjects lack the cognitive attributes required to reduce pain to the same degree as highsusceptible subjects. Although low-susceptible subjects do not lack the ability to reduce pain, the definition of the situation as related or as not related to hypnosis strongly influenced whether they exercised that ability. When instructions for analgesia were denned as hypnotic, 80% of our low-susceptible subjects failed to report any pain reduction. When the same instructions were not related to hypnosis, all of the lowsusceptible subjects reported some pain reduction and 90% of them reported reductions of 20% or more. At least two accounts can be offered for these findings. People who score low on an initial test of hypnotic susceptibility often hold negative attitudes toward hypnosis and negative expectations concerning their success at hypnotic responding even before the susceptibility test session (Barber, Spanos, & Chaves, 1974). Moreover, the fact that they responded poorly during the susceptibility test can only reinforce their self-conceptions as hypnotically unresponsive. Thus, when faced with a task like pain reduction m a situation defined as hypnotic, low-susceptible subjects may construe themselves as unable to respond successfuly and, as a result, may fail to exercise the cognitive coping that facilitates pain reduction. The importance of implicitly held expectations concerning coping ability on response to pain has been demonstrated in nonhypnotic contexts. For instance, Neufeld and Thomas (1977) used false feedback to manipulate subjects' expectations of their ability to cope with pain. Subjects were led to believe that relaxation enhanced pain tolerance. Those in one group were then provided with false feedback indicating that they had succeeded in relaxing during noxious stimulation, whereas those in another group were given false feedback indicating that they had failed to relax during noxious stimulation. Control subjects received no feedback. On a later test trial, those who had been given positive feedback showed significantly higher pain tolerance than did both the control subjects and those given negative feedback. It is important that none of the

groups differed significantly on either physiological or verbal report indexes of relaxation. Changes in pain tolerance resulted from changes in subjects' appraisals of their coping efficacy rather than from actual changes in relaxation. In the present study, the failure of low-susceptible hypnotic subjects to reduce pain may have involved a more deliberate process than the above account implies. At least some lowsusceptible subjects may be invested in presenting themselves as unresponsive to hypnosis and suggestion; as independent-minded people who are not easily led or manipulated. For instance, Jones and Spanos (1982) found that low-susceptible subjects given a hypnotic suggestion for increased auditory sensitivity responded in opposition to the demands of the suggestion. They exhibited a decrease (rather than an increase) in auditory sensitivity and a bias toward reporting the auditory signal as absent (rather than as present). In the present experiment, at least some low-susceptible hypnotic subjects may have purposely failed to initiate pain-reducing strategies to demonstrate that they could not be influenced by hypnosis. Obviously, these two accounts are not mutually exclusive, and future work is required to determine the conditions under which response failures in low-susceptible subjects reflect deliberate withholding as opposed to an expectancy-induced failure to exercise requisite abilities Changes m cognitive coping were influenced by treatments m parallel with changes in pain reporting. Thus, high-susceptible hypnotic subjects reported greater increments in cognitive coping as well as larger pain reductions than did low-susceptible hypnotic subjects. Instruction-alone subjects at all susceptibility levels reported increments in coping as well as decrements in pain as large as those reported by high-susceptible hypnotic subjects, and significantly larger than those reported by lowsusceptible hypnotic subjects. These findings are consistent with the notion that suggestioninduced pain reductions are moderated by subjects' active attempts at cognitively coping with noxious stimulation (e.g., Meichenbaum, 1977; Turk, Meichenbaum, & Genest, 1983; Spanos, 1982). They are also consistent with recent findings indicating that implicit, situationally induced expectations effect reported

MODERATING EFFECTS ON SUGGESTED ANALGESIA

pain by influencing subjects' use of cognitive coping strategies. For instance, Stam and Spanos (1980) found that high-susceptible subjects who anticipated a later hypnotic analgesia trial reported relatively little pain reduction when administered "waking" analgesia (suggestion alone), but high levels of pain reduction during hypnotic analgesia. High-susceptible subjects who did not anticipate a later hypnosis trial reported high levels of pain reduction when given suggestion alone. In short, informing high-susceptible subjects about a future hypnosis trial induced them to perform less than optimally when given a nonhypnotic suggestion. Stam and Spanos (1980) also found a strong correspondence between subjects' reports of cognitive coping and their degree of reported pain. Thus, their subjects seemed to meet implicitly conveyed expectations for differing levels of pain reduction by selectively employing (and failing to employ) cognitive coping strategies that led to the particular results desired. Along related lines, Spanos, Hodgms, Stam, and Gwynn (1984) found that experimental subjects exposed to noxious stimulation failed to use available cognitive coping strategies for pain reduction unless they were given explicit permission to do so. When given a cognitive coping strategy and instructed to use it, these subjects reported significant reductions in pain. Despite their proven success at reducing pain, however, these same subjects failed to engage in cognitive coping and failed to reduce pain on a later trial unless they were provided with explicit permission to do so. In other words, these subjects interpreted the absence of explicit permission for pain reduction as an injunction against coping with and reducing pain.1 Taken together with the present findings, these results underscore the social nature of the experimental pain assessment situation— a situation in which implicit as well as explicit situational demands are interpreted by subjects in terms of their own preconceptions and in terms of the self-impression they wish to convey through their responding. Thus, the relationship typically obtained between pretested hypnotic susceptibility and degree of suggested analgesia does not appear to reflect gradations in a stable cognitive capacity (e.g., facility for dissociation) that finds relatively direct expression in the analgesia-testing situation.

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Instead, this correlation seems to reflect differences in the attitudes and expectations that high- and low-susceptible subjects hold about hypnosis and about their own responsiveness to hypnotic procedures. In turn, these attitudes determine their willingness (or unwillingness) to initiate and maintain coping strategies that lead to reductions in reported pain. Because the attitudes that moderate subjects' use of coping strategies are situation specific, changes in the definition of the pain-testing situation (e.g., from related to hypnosis to unrelated to hypnosis) can lead to dramatic increments in the analgesia performance of low-susceptible subjects

' At least three hypotheses can be offered to account for the relationship between reports of increased coping and decreased pain The first hypothesis assumes that cognitive coping reduces the intensity of the sensory processes induced by the noxious stimulation The second hypothesis suggests that engagement in coping cognitions leads subjects to reevaluate the noxious events as less distressing and thereby as less painful than they initially believed This account does not assume that cognitive strategies reduce the levels of sensory stimulation produced by the noxious stimulation The third account holds that both reports of reduced pain and reports of increased coping involve public compliance with experimental demands in the absence of any changes in the private experience of pain In our opinion the available data concerning experimentally induced pain can be best accounted for by the second hypothesis (Spanos, 1982) Nevertheless, these three hypotheses are not mutually exclusive, and each may contribute something of value to a fuller understanding of pain and its mechanism

References Barber, T X (1969) Hypnosis A scientific approach New York Van Nostrand-Reinhold Barber, T X , & Hahn, K W., Jr (1962) Physiological and subjective responses to pain producing stimulation under hypnotically-suggested and waking-imagined "analgesia " Journal of Abnormal and Social Psychology, 65, 411-418 Barber, T X , Spanos, N P , & Chaves, J F (1974) Hypnosis, imagination and human potentialities New York Pergamon Press Chaves, J F , & Barber, T X (1974) Cognitive strategies, experimenter modeling, and expectation in the attenuation of pain Journal of Abnormal Psychology, 83, 356-363 Evans, M B , & P a u l , G L (1970) Effects of hypnotically suggested analgesia on physiological and subjective responses to cold stress Journal of Consulting and Clinical Psychology, 35. 262-371 Farthing, W G , Ventunno, M , & Brown, S W (1982, October) Comparison of three cognitive methods of pain

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control in subjects ofhigh and low hypnotizabihty Paper presented at the meeting of the Society for Clinical and Experimental Hypnosis, Indianapolis Hilgard, E. R (1977) The problem of divided consciousness A neodissociation interpretation Annals of the New York Academy of Sciences, 296, 48-59 Hilgard, E R., & Hilgard, J R (1975) Hypnosis in the relief of pain Los Altos, CA Kaufman Jones, B , & Spanos, N P. (1982) Suggestions for altered auditory sensitivity, the negative subject effect, and hypnotic susceptibility A signal detection analysis Journal of Personality and Social Psychology, 43, 637-647 Meichenbaum, D (1977) Cognitive-behavior modification New York Plenum Press Neufeld, W J., & Thomas, P (1977) Effects of perceived efficacy of a prophylactic controlling mechanism on selfcontrol under pain stimulation Canadian Journal of Behavioral Science, 9, 224-232. Spanos, N. P (1982) A social psychological approach to hypnotic behaviour In G Weary & H L. Mirels (Eds), Integrations of clinical and social psychology (pp 231 271) New York: Oxford University Press Spanos, N P., Barber, T. X., & Lang, G. (1974) Cognition and self-control Cognitive control of painful sensory input In H London & R E Nisbitt (Eds), Thought and feeling Cognitive alteration of feeling states (pp 141-158) Chicago Aldine Spanos, N P, Brown, J M , Jones, B , & Homer, D (1981) Cognitive activity and suggestions for analgesia in the reduction of reported pain Journal of Abnormal Psychology, 90, 554-561 Spanos, N P,& Hewitt, E C (1980) The hidden observer in hypnotic analgesia Discovery or experimental creation? Journal ofPersonality and Social Psychology, 39, 1201-1214 Spanos, N P., Hodgins, D C , Stam, H J., & Gwynn,

M. (1984) Suffering for science. The effects of implicit social demands on response to experimentally induced pam Journal of Personality and Social Psychology, 46, 1162-1172 Spanos, N P., McNeil, C , Gwynn, M. I., & Stam, H. J (1984) The effects of suggestion and distraction on reported pain in subjects high and low on hypnotic susceptibility Journal of Abnormal Psychology, 93, 277284 Spanos, N P., Ollerhead, V G., & Gwynn, M. I (1983). A comparison of three cognitive treatments for the control of pain magnitude and pain tolerance in experimental subjects Unpublished manuscript, Carleton University Spanos, N P., Radtke, H L , Hodgins, D C , Stam, H J , & Bertrand, L D (1983) The Carleton University Responsiveness to Suggestion Scale* Normative data and psychometric properties. Psychological Reports, 53, 523535 Spanos, N P., Radtke-Bodonk, H L , Ferguson, J D., & Jones, B (1979) The effects of hypnotic susceptibility, suggestions for analgesia, and the utilization of cognitive strategies on the reduction of pam. Journal of Abnormal Psychology, 88, 282-292 Spanos, N P., Stam., H J.,& Brazil, K (1981) The effects of suggestion and distraction on coping ideation and reported pam Journal of Mental Imagery, 5, 75-90 Stam,H J.,& Spanos, N P (1980) Experimental designs, expectancy effects, and hypnotic analgesia Journal of Abnormal Psychology, 89, 751-762 Turk,D C , Meichenbaum, D., & Genest, M (1983) Pain and behavioral medicine A cognitive-behavioral perspective New \brk Guilford Press

Received August 26, 1983 Revision received March 12, 1984 •