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International Journal of Clinical
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The Cognitive Demands of
Hypnotic Response
a
Miriam Wyzenbeek & Richard A. Bryant
a
a
University of New South Wales, Sydney, Australia
Published online: 18 Nov 2011.
To cite this article: Miriam Wyzenbeek & Richard A. Bryant (2012) The Cognitive Demands
of Hypnotic Response, International Journal of Clinical and Experimental Hypnosis, 60:1,
67-80, DOI: 10.1080/00207144.2011.622197
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Intl. Journal of Clinical and Experimental Hypnosis, 60(1): 67–80, 2012
Copyright © International Journal of Clinical and Experimental Hypnosis
ISSN: 0020-7144 print / 1744-5183 online
DOI: 10.1080/00207144.2011.622197
THE COGNITIVE DEMANDS OF HYPNOTIC
RESPONSE
Miriam Wyzenbeek and Richard A. Bryant1
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University of New South Wales, Sydney, Australia
Abstract: This study tests the proposal that hypnotic responding is
effortless. The authors compared the responses of high and low hypnotizable participants (N = 70) in and out of hypnosis on a dual-task
paradigm in which they were required to maintain hypnotic blindness during presentation of visual stimuli of varying salience intensities while simultaneously completing a secondary task. Whereas
high hypnotizable participants in both hypnosis and wake conditions
reported comparable levels of conviction in the hallucination suggestion, hypnotized highs performed poorer on the secondary task
when the stimulus was present. Performance on the secondary task
deteriorated when the visual stimulus was intensified. These findings
contradict the notion that hypnotic response is not demanding on cognitive resources and suggest that increased effort is required to resolve
the extent of conflict between reality and suggestion.
During hypnosis, individuals are typically required to think, to feel,
and to behave in ways that are incongruent with reality. The extent
to which a hypnotized person can successfully respond to a hypnotic
suggestion depends on their capacity to resolve the conflict between
the hypnotist’s suggested experience and reality (Bryant & Mallard,
2005; Kihlstrom & Hoyt, 1988). One of the outstanding issues regarding hypnotic response is the extent to which this response is effortful
or occurs automatically. According to Hilgard’s original (1986, 1994)
neodissociation theory, hierarchically organized cognitive subsystems
are governed by an executive control system, which during hypnosis is dissociated from normal processing by an amnesic-like barrier.
This amnesic barrier purportedly limits participants’ awareness of their
responses to hypnotic suggestions, resulting in the perception that
responses are automatic. This theory suggests that hypnotic responses
are more cognitively demanding than nonhypnotic responses because
of the cognitive demands associated with maintenance of the amnesic
barrier (Hilgard, 1986). In contrast, the more recent dissociated control
Manuscript submitted April 6, 2009; final revision accepted December 20, 2010.
1 Address correspondence to Richard A. Bryant, School of Psychology, University of
New South Wales, Sydney, NSW 2052, Australia. E-mail: [email protected]
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MIRIAM WYZENBEEK AND RICHARD A. BRYANT
theory posits that that hypnosis weakens the executive control over
subsystems, thereby enabling the hypnotist’s suggestions to directly
influence subsystems and to activate responses without cognitive
mediation (Bowers, 1992; Woody & Bowers, 1994). This position implies
that hypnotic responses can occur with fewer cognitive demands than
nonhypnotic responses (Woody & Sadler, 2008).
There is some evidence to support the dissociated control theory.
Bowers and colleagues conducted several studies that indicated that
hypnotic tasks were achieved with less effort than nonhypnotic tasks.
These studies found that, unlike a cognitive behavioral stress inoculation procedure, hypnotic analgesia suggestions did not interfere with
a concurrent cognitive task (Miller & Bowers, 1993), and that hypnotic
analgesia required fewer attentional resources than stress inoculation
procedures (Eastwood, Gaskowski, & Bowers, 1998). In contrast, there
is also indirect evidence to suggest that hypnotic responding may be
cognitively demanding. Qualitative analyses of hypnotic responding
have demonstrated that hypnotized participants resolve the conflict
between reality and suggestion by effortfully engaging in strategies
that minimize the conflict (McConkey, 1983; Sheehan & McConkey,
1982). Specifically, hypnotized individuals who apply active constructive strategies to reduce the incongruity between suggestion and reality
achieve hypnotic response more successfully than those who do not
(Bryant & Mallard, 2004; Bryant & McConkey, 1989a, 1989b, 1990a,
1990b; Mallard & Bryant, 2001a, 2001b, 2006; Sheehan & McConkey,
1982). There is also behavioral evidence suggesting that hypnotic
response is cognitive demanding. Bryant and McConkey (1990a) suggested hypnotic blindness to participants who subsequently performed
a visual decision task; this study found that hypnotically blind participants responded slower on a secondary word task when performing
a decision task with visual cues present than when they were absent.
This pattern suggested that the cognitive demands associated with
the experience of hypnotic blindness reduced the cognitive resources
available for performing a task unrelated to the experience of hypnotic blindness. Kirsch and colleagues demonstrated that the additional
cognitive load of a competing task hindered the response to some
hypnotic suggestions (Kirsch, Burgess, & Braffman, 1999; Kirsch &
Lynn, 1998). Finally, Tobis and Kihlstrom (2010) reported that responding to a posthypnotic suggestion was compromised by a competing
task, suggesting posthypnotic responding is demanding of cognitive
resources.
Although there is considerable indirect evidence regarding the
extent to which hypnotic responding is cognitively demanding, there is
a need to directly test the cognitive demands associated with responding to the conflict between reality and suggestion during hypnosis.
Using a dual-task paradigm, we assessed cognitive load demands
associated with responding under varying hypnotic conflict salience
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COGNITIVE DEMANDS AND HYPNOSIS
69
conditions as a function of hypnosis and of hypnotizability. It is
important to manipulate hypnotizability because high levels of
hypnotizability are associated with a range of cognitive abilities.
During hypnosis, high hypnotizable participants possess an increased
capacity for selective attention (Acosta & Crawford, 1985; Dolby
& Sheehan, 1977; Wallace, 1979). Accordingly, this study compared
responses of high and low hypnotizable participants. Similarly, it is
important to control for hypnosis because of evidence that high hypnotizable participants also have a greater capacity for selective attention
outside of hypnosis (Crawford, 1994). It is therefore important to compare the cognitive demands associated with responding to a suggestion
in and out of hypnosis. In this study, we compared the responses
of high and low hypnotizable participants in and out of hypnosis
on a dual-task paradigm in which they were required to maintain
hypnotic blindness during presentation of visual stimuli of varying salience intensities while simultaneously completing a secondary
task. We hypothesized that maintaining a hypnotic suggestion during
increased conflict between reality and suggestion would be associated
with increased cognitive load. Specifically, we predicted that highs in
the hypnosis condition would perform poorer on the secondary decision task than highs in the wake condition. On the premise that lows
would not experience the negative visual hallucination suggestion, it
was predicted that lows would display comparable performances on
the secondary decision task across the conflict salience conditions.
Method
Participants
Participants were first-year undergraduate psychology students at
the University of New South Wales, who received 2 hours research
credit for their participation. Thirty-five (21 female and 14 male)
high hypnotizable participants (highs) of mean age 18.8 years (SD =
1.28) and 35 (19 female and 16 male) low hypnotizable participants
(lows) of mean age 19.37 years (SD = 2.40) participated in the experiment. Participants were selected on the basis of their extreme scores
on the 10-item modified versions of the group-administered Harvard
Group Scale of Hypnotic Susceptibility: Form A (HGSHS:A; Shor
& Orne, 1962) and the individually administered Stanford Hypnotic
Susceptibility Scale: Form C (SHSS:C; Weitzenhoffer & Hilgard, 1962).
Highs scored in the range 7.5–10 on the HGSHS:A (M = 8.74, SD =
0.98) and in the range 7.5–10 on the SHSS:C (M = 8.4, SD = 0.98). Lows
scored in the range 0–3 on the HGSHS:A (M= 1.23, SD = 0.87) and
in the range 0–3 on the SHSS:C (M = 1.2, SD = 1.02). High and low
hypnotizable participants were randomly assigned to hypnosis or wake
conditions.
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MIRIAM WYZENBEEK AND RICHARD A. BRYANT
Materials
The auditory stimuli used in the secondary decision task included
a recording of animate and inanimate noun words, which were stored
as audio files in Windows .wav format. These words were presented
via a laptop computer using the DMDX experiment software program. The words were recorded 3 seconds apart in three sets of 32.
The presentation order of the three sets was randomized, resulting
in six possible secondary decision task conditions. The words in each
set were matched for syllabic length and word frequency (Kucera &
Francis, 1967). Each set consisted of eight target words (animate nouns)
and 24 nontarget words (inanimate nouns). Participants’ responded
via an external keyboard, positioned on the participant’s lap. DMDX
registered participants’ response accuracy and latency for each word.
Response latencies were measured in milliseconds, with a maximum
response latency of 3 seconds.
The visual stimuli used for the negative visual hallucination consisted of five slides, projected singularly on a wall in front of the
participant (approximately at eye-level), using a Kodak Carousel S-AV
2050 model projector. Each slide was presented for 120 seconds. All
of the slides had the same background, which was closely matched
to the color of the wall that they were projected on. Four of the
slides featured an equally sized target image of a red circle on a
white background, which had a projected vertical diameter of 10 cm
and a projected horizontal diameter of 13 cm. The color intensity of
the target image was incrementally stronger in the Low (luminance:
10) and High (luminance: 50) conflict conditions, respectively. The
target image was not present in the “No Conflict” condition. The
experimenter manually changed the slides to alter stimulus presentation. The projection order of slides “high,” “low,” and “no conflict”
was counterbalanced between participants. The projector’s lens and
the participant’s chair were both aligned to face the same position
on the same wall, with participants sitting 171 cm from the projected stimulus. The projector was positioned 200 cm from the wall
that was facing the participant. The two tasks chosen for this study
used different sensory and response channels to ensure that any interference effects reflected resource limitations rather than structural
bottlenecks.
Procedure
Following written informed consent procedures, participants were
informed that the study was concerned with people’s reactions to
different tasks. Participants in the hypnosis condition were then administered a standard hypnotic induction procedure, based on the SHSS:C.
Participants in the wake condition were given two filler tasks, time
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COGNITIVE DEMANDS AND HYPNOSIS
71
matched with the hypnotic induction. The first filler task involved
dividing an L-shape into four equal-sized portions. The second filler
task required participants to match pairs of numbers and names. The
experimenter then tested participants on a number of suggestions that
were unrelated to the present study.
The experimenter then informed participants that they would be
asked to perform two tasks concurrently: a primary visual task and
a secondary auditory decision task. Participants were advised that the
auditory task would require them to listen to a list of nouns and to identify the animate nouns by pressing “enter” on the keyboard that was
positioned on their lap. Participants were told that speed and accuracy
were important on the word task and were given a practice trial consisting of 10 words (eight inanimate nouns and two animate nouns).
The experimenter reminded participants that they would be asked to
perform the word task while looking at a projected circle on the wall in
front of them. The experimenter emphasized that the primary task of
looking at the circle should be performed to the best of the participant’s
ability and that the secondary word task may take care of itself. The
experimenter then administered a negative visual hallucination suggestion for the circle. The suggestion instructed participants that the
circle would disappear. This suggestion continued for 2 minutes and
repeatedly stated that the circle would become invisible to them and
that it would become so faint that they could not see it any longer.
The experimenter then asked participants to describe what they saw
on the wall, and an additional suggestion was given for participants
who still reported seeing the circle. The experimenter then asked participants to rate their confidence that there was nothing on the wall
(1 = not at all sure, 10 = very sure). The experimenter then instructed
participants to focus their attention on the shaded area of the wall as
they completed the auditory task. The experimenter then projected the
appropriate slide onto the wall (high, low, or no conflict) in front of
the participant and waited 10 seconds before commencing the decision
task. The 10-second delay between slide projection and word-task commencement was aimed at providing participants with time to adjust to
the visual target stimulus’s differing conflict intensity. The decision task
consisted of 32 words (24 inanimate and eight animate), spaced 3 seconds apart. After the 32nd word, the experimenter paused the decision
task and asked participants’ conviction rating that there was no circle on the wall (1 = not at all sure, 10 = very sure). This procedure was
repeated for the three counterbalanced conflict conditions. Following
this, the experimenter terminated the decision task, removed the keyboard from participants’ laps and suggested to participants that they
could see the circle clearly. A deinduction procedure was then administered to participants in the hypnosis condition, and the session was
terminated.
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MIRIAM WYZENBEEK AND RICHARD A. BRYANT
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Results
Preliminary Analyses
To determine if the word order or conflict order influenced participants’ responses, separate 6 (Word Order) × 3 (Conflict Order) analyses
of variance (ANOVAs) were conducted on initial conviction ratings of
the negative visual hallucination, correct responses on the secondary
task, and response latencies on the secondary task. There were no significant main or interaction effects on any of these analyses, indicating
that responses to the suggestion and responses on the secondary word
task were not influenced by order of word presentation or conflict
condition. Subsequent analyses do not include word order or conflict
condition order. Separate 2 (Hypnotizability) × 2 (Induction) ANOVAs
on age and HGSHS:A and SHSS:C scores indicated no significant main
or interaction effects for age. As expected, there were significant main
effects for HGSHS:A scores, F(1, 66) = 1139.15, p = .001, η2 = .95, and
SHSS:C scores, F(1, 66) = 933.70, p = .001, η2 = .93, but no interaction effects. That is, hypnotizability did not differ between induction
conditions.
Hallucination Ratings
Table 1 presents the mean hallucination conviction ratings for each
conflict salience condition. A 2 (hypnotizability) × 2 (induction) × 3
(conflict salience) mixed-model ANOVA of conviction ratings indicated
significant main effects for hypnotizability, F(1, 64) = 34.24, p < .001,
η2 = .35, conflict salience, F(2, 128) = 238.86, p < .001, η2 = .83, and
a significant Hypnotizability × Conflict Salience interaction effect, F(2,
128) = 31.07, p < .001, η2 = .15. Highs reported more conviction in the
Table 1
Mean Conviction Ratings for the Negative Hallucination Suggestion During Each
Conflict Salience Condition
Induction Condition
and Hypnotizability
Wake
Low
High
Hypnosis
Low
High
Conflict Salience
High
Low
None
1.5 (2.12)
3.29 (2.73)
1.06 (0.24)
6.24 (3.23)
9.39 (2.12)
9.59 (1.23)
1.63 (1.49)
4.22 (2.98)
1.73 (1.62)
6.19 (3.20)
9.93 (1.23)
8.89 (2.14)
Note. For conviction ratings: 1 = “not at all sure,” 10 = “very sure.” High = high-conflict
salience condition; Low = low-conflict salience condition; None = no-conflict salience
condition. Standard deviations appear in parentheses.
COGNITIVE DEMANDS AND HYPNOSIS
73
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hallucination than lows. Further, participants reported more conviction
during the no conflict (p < .001) and low conflict (p < .001) conditions.
Post hoc Tukey comparisons indicated that highs reported significantly
more conviction in the hallucination than lows during both the high
conflict, t(68) = 3.94, p < .001, and low conflict, t(67) = 8.45, p < .001,
conditions.
Secondary Task
Table 2 presents the mean number of correct responses and response
latencies. A 2 (Hypnotizability) × 2 (Induction) × 3 (Conflict Salience)
mixed-model ANOVA of correct responses yielded a significant interaction between Hypnotizability and Conflict Salience, F(2, 132) = 3.49,
p < .05, η2 = .05, and a significant three-way interaction effect between
Hypnotizability, Induction, and Conflict Salience, F(2, 132) = 3.43,
p < .05, η2 = .05. Whereas all participants made a similar number of
correct responses during the no conflict and the low-conflict salience
conditions, highs made fewer correct responses during the high-conflict
condition compared to lows, t(68) = 2.23, p > .05. To clarify the
three-way interaction, separate two-way ANOVAs were conducted for
lows and highs, respectively. In terms of lows, a 2 (Induction) × 3
(Conflict Salience) mixed-model ANOVA of correct responses indicated
Table 2
Mean Number of Correct Responses and Response Latencies on the Secondary Task
Induction Condition
and Hypnotizability
Conflict Salience
High
Low
None
Correct Responses
Wake
Low
High
Hypnosis
Low
High
7.06 (1.43)
6.88 (1.05)
7.06 (1.16)
7.12 (0.93)
7.00 (1.46)
6.88 (0.70)
7.41 (0.62)
6.44 (0.98)
7.65 (0.61)
7.34 (0.97)
7.24 (0.66)
7.44 (0.92)
Responses Latencies
Wake
Low
High
Hypnosis
Low
High
1450.56 (365.32)
1612.74 (364.45)
1451.14 (275.17)
1539.78 (300.38)
1486.42 (373.96)
1592.89 (275.04)
1449.30 (240.55)
1828.41 (359.45)
1349.22 (202.86)
1635.83 (367.90)
1422.63 (179.08)
1560.21 (279.08)
Note. High = high-conflict salience condition; Low = low-conflict salience condition:
None = no-conflict salience condition. Response latencies are measured in milliseconds.
Standard deviations appear in parentheses.
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MIRIAM WYZENBEEK AND RICHARD A. BRYANT
no significant effects. In terms of highs, a 2 (Induction) × 3 (Conflict
Salience) mixed-model ANOVA of correct responses indicated a significant main effect for Conflict Salience, F(2, 66) = 5.00, p < .01, η2 = .21,
and a significant Induction × Conflict Salience interaction effect, F(2,
66) = 4.39, p < .05, η2 = .21. Specifically, highs made significantly fewer
correct responses in the high-conflict condition than in the low- (p <
.05) or no (p < .01) conflict conditions. Further, highs in the hypnosis
condition made fewer correct responses in the high-conflict condition
than in the no conflict salience condition, t(17) = 4.37, p < .001.
A 2 (hypnotizability) × 2 (induction) × 3 (conflict salience) mixedmodel ANOVA of response latencies yielded significant main effects
for hypnotizability, F(1, 66) = 9.07, p = .004, η2 = .12, conflict salience,
F(2, 132) = 4.52, p = .01, η2 = .12, and a significant Induction ×
Conflict Salience interaction effect, F(2, 132) = 3.39, p < .05, η2 = .05.
Highs responded slower than lows. Participants responded slower during the high-conflict condition compared to low-conflict, t(69) = 2.97,
p < .005, and no conflict, t(69) = 2.00, p < .05, salience conditions.
Post hoc comparisons indicated that whereas participants in the wake
condition had comparable response latencies across the three conflict conditions, participants in the hypnosis condition had slower
responses in the high-conflict condition compared to the low-conflict
(p < .001) and no conflict (p < .005) conditions.
Responses of Participants Experiencing the Negative
Visual Hallucination
On the basis that rating their belief that the circle was not present at
least 5 (out of the possible 10) indicated passing the suggestion, 27 highs
(39%) and no lows experienced the hallucination suggestion. Of these
27 participants, 12 were in the wake induction condition and 15 in the
hypnosis induction condition. To assess the cognitive demands associated with successfully experiencing the negative visual hallucination
during varying conflict intensities, the previous analyses for the secondary task were recalculated on these 27 participants (see Table 3).
A 2 (induction) × 3 (conflict salience) mixed-model ANOVA of correct
responses on the secondary task yielded a significant main effect for
conflict salience, F(2, 24) = 3.91, p = .03, η2 = .25, demonstrating that
participants made fewer correct responses during the high-conflict (M
= 6.67, SD = 0.92) than the low-conflict (M = 7.11, SD = 1.09), t(26)
= 2.00, p = .056, and no conflict (M = 7.22, SD = 0.85), t(26) = 2.75,
p < .01, conditions. This analysis also yielded a significant Induction
× Conflict Salience interaction effect, F(2, 24) = 5.94 p = .008, η2 =
.33. Whereas highs in the wake condition had comparable response
accuracy rates across the three conflict conditions, participants
COGNITIVE DEMANDS AND HYPNOSIS
75
Table 3
Mean Number of Correct Responses and Response Latencies on the Secondary Task for
Participants Who Experienced the Hallucination Suggestion
Induction Condition
Conflict Salience
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High
Correct Responses
Wake
Hypnosis
Response Latencies
Wake
Hypnosis
7.00 (0.739)
6.40 (0.986)
Low
7.17 (0.937)
7.07 (1.223)
None
6.92 (0.669)
7.47 (0.915)
1536.08 (277.25) 1506.63 (306.12) 1536.76 (242.25)
1839.82 (367.35) 1648.52 (393.83) 1592.58 (273.25)
Note. High = high-conflict salience condition; Low = low-conflict salience condition;
None = no-conflict salience condition. Response latencies are measured in milliseconds.
Standard deviations appear in parentheses.
in the hypnosis condition made more correct responses during the lowconflict, t(14) = 2.32, p < .05, and no conflict, t(14) = 4.30, p < .01,
conditions compared to the high-conflict condition. A 2 (induction) × 3
(conflict salience) mixed-model ANOVA of response latencies yielded
a significant interaction effect between induction and conflict salience,
F(2, 24) = 3.20, p = .04, η2 = .24. Participants in the hypnosis condition
responded slower than participants in the wake condition during the
high-conflict salience condition, t(25) = 2.37, p < .05.
Discussion
Overall, there was poorer performance on the secondary task
when high hypnotizable participants were attempting to respond
to the hypnotic suggestion during hypnosis, and this influence was
particularly apparent when the discrepancy between reality and
suggestion was more salient. The finding that participants performed
worse on the secondary task during high conflict relative to no conflict
supports Bryant and McConkey’s (1990a) finding that the presence
of conflicting reality information during hypnotic responding places
demands on cognitive resources. The observation that performance
on the secondary task deteriorated during high conflict relative to low
conflict extends previous evidence by demonstrating that the drain on
cognitive resources depends on the extent of the discrepancy between
reality and suggestion.
The cognitive demands associated with managing the conflicting
reality information were greater for highs than lows. As lows did
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MIRIAM WYZENBEEK AND RICHARD A. BRYANT
not respond to the suggestion, they did not need to resolve the
conflict and hence they had greater resources available for the secondary task. In resolving the conflict, high hypnotizable individuals
may have expended more effort for several reasons. High hypnotizables tend to use more active cognitive strategies than lows (Bryant
and McConkey, 1989b; Sheehan & McConkey, 1982), which presumably involves more cognitive resources. It is also possible that high
hypnotizable participants were motivated to comply with experimental
tasks and consequently used more cognitive resources to experience the
hallucination. Highs tend to be more motivated than lows (Braffman &
Kirsch, 1999) and, in the context of the current experiment, the highs
may have been motivated to expend more effort in responding to the
suggestion as it became more difficult.
Intriguingly, highs in the hypnosis and wake conditions reported
comparable levels of conviction in the negative visual hallucination.
This finding accords with previous reports of highs being able to
successfully respond to hypnotic suggestions in and out of hypnosis
(Bryant & Kapur, 2006; Kirsch & Braffman, 2001). Despite this finding, highs in the hypnosis condition used more cognitive resources
than those in the wake condition. Although previous commentaries
have noted that performing a task hypnotically is less cognitively
demanding than performing that same task nonhypnotically (Ruehle
& Zamansky, 1997), the use of a dual-task paradigm in this study indicates the cognitively demanding nature of responding in hypnosis. Our
current finding is supported by some early evidence that hypnotic
responding is more taxing on cognitive resources than nonhypnotic
responding (Fehr & Stern, 1967), and with evidence of increased cerebral metabolism, which is indicative of increased cognitive effort,
during hypnosis (Crawford, Brown, & Moon, 1993).
The current findings are consistent with theories that recognize that
a core mechanism in successful response to a hypnotic suggestion is
the capacity to resolve the conflict between reality and suggestion
by engaging appropriate cognitive strategies (Sheehan & McConkey,
1982; Spanos, 1986). This perspective emphasizes that hypnotized
individuals engage in active problem-solving strategies during hypnosis, and the effort required to maintain the resolution of the conflict
between reality and suggestion will depend on the degree of conflict
(McConkey, 1983). This interpretation accords with previous evidence
that hypnotized participants manage increased conflict by engaging in
effortful strategies to resolve the conflict between suggestion and reality (Bryant & McConkey, 1989a; Mallard & Bryant, 2006). Additionally,
Bryant and Mallard (2003) suggested that participants exposed to
nonhypnotic suggestions do not display the same commitment as
participants exposed to hypnotic suggestions to respond successfully.
Accordingly, although highs in both conditions were able to achieve
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COGNITIVE DEMANDS AND HYPNOSIS
77
the suggested hallucination, those participants in the hypnosis condition may have performed poorer on the secondary task because
the hypnotic induction increased their motivation to use cognitively
demanding strategies in order to maintain their experiences of the
hallucination suggestion.
We note several methodological limitations of this study. First,
although we endeavored to compare hypnosis and wake conditions,
it is possible that participants in the wake condition interpreted the
context as hypnotic. Previous research has demonstrated that previous experiences of hypnosis and the performance of hypnotic tasks
are sufficient to produce the experience of hypnosis (Kirsch, Wickless,
& Moffitt, 1999). Participants had previously undergone two separate
hypnosis-screening sessions to confirm their hypnotizability levels, and
this may have primed participants in the wake condition to experience
the session as a hypnosis session. Second, it is possible that the differential responses to the hallucination suggestion and to the secondary
task may have been influenced by demand characteristics, as participants responded to perceived expectations of the experimenter. Future
replications of this study could employ Orne’s (1979) real-simulating
paradigm to compare the performance of real hypnotized individuals with those of simulating unhypnotized individuals to index the
potential role of demand characteristics on the observed responses.
In summary, this study represents evidence that successful responding to a hypnotic suggestion is demanding on cognitive resources,
and these demands are increased according to the degree of conflict
between the suggestion and reality. The finding that this pattern is specific to high hypnotizable participants who have undergone a hypnotic
induction challenges notions that responding to a hypnotic suggestion is automatic or effortless. Theories of hypnosis need to recognize
that despite attributions of involuntariness that participants often make
about hypnotic responding (Lynn, Rhue, & Weekes, 1990), successful
responding to suggestions that conflict with reality are demanding on
cognitive resources. We recognize that the role of cognitive effort in
hypnotic response is complex and is probably dependent on the nature
of the suggestion and the context in which it is tested (Lynn, Kirsch,
& Hallquist, 2008). Future research could usefully employ dual-task
paradigms to index the cognitive resources required by different suggestions in and out of hypnosis to document the extent to which effort
is required to develop and maintain a hypnotic response.
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Kognitive Erforderungen der Hypnotischen Reaktion
Miriam Wyzenbeek und Richard A. Bryant
Abstrakt: Diese Studie testete die Unterbreitung daß die hypnotische
Reaktion mühelos erfolgt. Die Autoren verglichen die Reaktionen von
hoch- und geringhypnotisierbaren Teilnehmern (N = 70) unter und
außer Hypnose in einem Doppelaufgaben Paradigma in dem sie dazu
verpflichtet wurden, hypnotische Blindheit während der Vorstellung optischer Stimuli unterschiedlicher Intensitäten beizubehalten und gleichzeitig
eine zweite Aufgabe zu bewältigten. Während die hochhypnotisierbaren
Teilnehmer im Hypnose- als auch Wachzustand vergleichbare Maße der
Überzeugung an der halluzinierten Suggestion berichteten, verrichteten
hypnotisierte Hochhypnotizierbare die sekundäre Aufgabe schlechter in
der Gegenwart des Stimuluses. Die Bewerkstelligung der sekundären
Aufgabe verschlechterte sich wenn der optische Stimulus verstärkt wurde.
Diese Resultate widersprechen der Annahme daß die hypnotische Reaktion
keine kognitive Bedürfnisse erfordert und deuten darauf hin, daß mehr
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MIRIAM WYZENBEEK AND RICHARD A. BRYANT
Anstrengung erforderlich ist den Umfang des Konfliktes zwischen Realität
und Suggestion zu lösen.
Elvira V. Lang, MD, FSIR, FSCEH
Hypnalgesics, LLC, Brookline, MA, USA
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Les exigences cognitives d’une réaction hypnotique
Miriam Wyzenbeek et Richard A. Bryant
Résumé: Les auteurs de cette étude ont testé l’hypothèse selon laquelle
la réaction hypnotique n’exige aucun effort. Ils ont comparé les réactions
de participants hautement hypnotisables avec celles de participants faiblement hypnotisables (N = 70) en état d’hypnose et en état d’éveil, selon un
paradigme de la tâche double, en vertu duquel il leur était demandé de
maintenir une cécité hypnotique durant la présentation de stimuli visuels
d’intensité variable, tout en effectuant simultanément une seconde tâche.
Alors que les participants hautement hypnotisables démontraient, tant en
état d’hypnose qu’en état d’éveil, des niveaux comparables de conviction
dans la suggestion hallucinatoire, la performance des sujets hautement
hypnotisables dans la seconde tâche s’est révélée inférieure en présence
du stimulus. L’accomplissement de la tâche secondaire diminuait avec
l’intensification du stimulus visuel. Ces résultats contredisent la notion
selon laquelle la réaction hypnotique n’exige pas de ressources cognitives,
et semblent indiquer la nécessité de fournir un effort supplémentaire pour
résoudre le conflit séparant la réalité de la suggestion.
Johanne Reynault
C. Tr. (STIBC)
Las demandas cognitivas de la respuesta hipnótica
Miriam Wyzenbeek y Richard A. Bryant
Resumen: Este estudio evalúa la propuesta de que la respuesta hipnótica no
requiere esfuerzo. Los autores compararon las respuestas de participantes
altamente y poco hipnotizables (n = 70) dentro y fuera de hipnosis en un
paradigma de actividad dual en donde se les requirió que mantuvieran una
ceguera hipnótica durante la presentación de estímulos visuales con una
intensidad de prominencia variante mientras simultáneamente completaban
una actividad secundaria. Mientras que los participantes altamente hipnotizables, en ambas condiciones bajo hipnosis y en estado de vigilia, reportaron
niveles comparables de convicción en la alucinación sugerida, la ejecución
en la tarea secundaria durante hipnosis de los altamente hipnotizables fue
más pobre cuando el estímulo estuvo presente. El desempeño en la actividad
secundaria se deterioró cuando los estímulos visuales se intensificaron. Estos
hallazgos contradicen la noción de que la respuesta hipnótica no demanda
recursos cognitivos y sugiere que se requiere mayor esfuerzo para resolver el
grado de conflicto entre la realidad y la sugerencia.
Omar Sánchez-Armáss Cappello
Autonomous University of San Luis Potosi,
Mexico