Hypnosis research owes its development to clinical methods. However proto- studies fail publication and/or efficacy criteria.
We know nothing about the specificity of hypnosis in terms of its effects unless we measure hypnotizability. It’s important that, even though lows may respond due to placebo etc., we not fool ourselves about what contributes to success.
Proto-studies lack literature survey, e.g. not citing prior research.
Case study research is helpful as a first step in furthering our knowledge. Key is careful observation and description. Fromm, 1981, wrote, “The purpose of a clinical manuscript must be to communicate to other clinicians new hypotheses, observations and findings which expand the professional horizon; or to present in detail new or modified techniques. It is important to state in clear cut, concrete form what was actually done so others can replicate, test, or apply the procedure to their own patients.”
Barnier, Amanda J.; McConkey, Kevin M. (1995, November). Posthypnotic suggestion: Knowing when to stop helps to keep it going. [Paper] Presented at the annual meeting of the Society for Clinical and Experimental Hypnosis, San Antonio, TX.
NOTES 1:
Posthypnotic suggestion sometimes leads to compulsive and involuntary responding, but we have little information about the parameters of such a response. In some research in our laboratory, we found that subjects who were given a posthypnotic suggestion that encouraged them to experience a desire to respond, showed a different pattern of response from those simply told to make a specific behavioral response. In another study, we gave subjects a posthypnotic suggestion to mail a postcard every day to the experimenter; some subjects were told to respond until they saw the hypnotist again (termination), others were given no specific information about how long they should respond (no termination). Those expecting a termination to the suggestion showed a different pattern of response across 16 weeks of testing. Thus, the information included in the suggestion about how or when to respond influences posthypnotic responding.
Present Experiment: Laboratory test of including specific information in the posthypnotic suggestion about how long to respond – cancellation cue vs. no cancellation cue. Responding indexed on four different tests: formal, embedded, informal, postexperimental. Also used real/simulating methodology. We expected that responding would decline across the four tests, but that the decline would be slowest for those expecting a cancellation cue.
Methodology: High hypnotizable subjects scored 8-10 on SHSS:C, lows scored 0- 3 on SHSS:C. Given real/simulating instructions (Orne, 1959). Formal test was given immediately after deinduction; embedded test was given during an inquiry question; informal test was given as the hypnotist appeared to terminate the experiment and leave the room; postexperimental test was given by another experimenter during a postexperimental inquiry. The suggestion was to cough when Ss heard a particular response cue.
Results: On the forma test, there was no difference between reals or simulators in either the cue or no cue condition, although simulators in the cue condition tended to overplay their response. Across the tests, responding declined. In particular, the majority of reals and simulators in the no cue condition stopped responding after the formal test. In the cue condition, reals and simulators responded similarly on the embedded test, but differently on the informal test; more reals than simulators continued to respond across the tests. Few subjects responded on the postexperimental test. Subjects’ postexperimental comments indicated that reals and simulators in the no cue condition believed that one response was sufficient; simulators in the cue condition were confused about whether to keep responding, and reals in the cue condition responded compulsively across the test.
Conclusions:
The inclusion of a cancellation cue in a posthypnotic suggestions maintains responding for a longer period. Responding posthypnotically is not explained solely by demand characteristics. Rather, individuals respond on the basis of their interpretation of the implied intent of the hypnotist’s message (c.f., Sheehan, 1971). Responding changes across test types. These findings contribute to a model of posthypnotic responding. They point to the active responding of hypnotized individuals (c.f., Kihlstrom: experimental subjects try to make sense of the message of the suggestions and instructions they receive).
Covino, Nicholas A. (1995, November). Rising to debate or rising to De Bait!.
[Paper] Presented at the annual meeting of the Society for Clinical and Experimental Hypnosis, San Antonio, TX.
NOTES:
As clinicians we need to embrace what researchers provide, but they need to pay attention to what clinicians provide, which is not myth and not fantasy.
Eastwood, John D.; Gaskaski, Peter; Bowers, Kenneth S. (1995, November). Frequency of pain reporting and analgesia: Exploration of a possible interaction. [Paper] Presented at the annual meeting of the Society for Clinical and Experimental Hypnosis, San Antonio, TX.
NOTES 1:
Two theories of pain control by hypnosis currently exist: 1. Socio-cognitive model – patient actively copes with noxious stimulus. Hypnotic analgesia should be like cognitive techniques like stress inoculation training. It requires deliberate effort. 2. Dissociative control model – pain reduction requires little cognitive effort.
These 2 theories have different predictions. He explains “ironic effects” theory, in which person must identify pain to reduce pain. Wagner’s reflexivity constraint: any process of mental control must be consistent with state we are trying to create.
This investigation involved 25 Highs and 24 Lows who reported pain, produced by strain gauge. Taught either hypnotic analgesia or stress inoculation. Reported every 5 sec (high load) or 45 sec (low load). Subtracted report from baseline to make pain reduction scores. Highs in hypnosis had no difference in pain reduction under high or low mental load. For the other 3 groups (Highs under stress inoculation; Lows under either hypnosis or stress inoculation) the results were different. That is, for Highs in hypnosis the mean of pain reduction scores was the same even when challenged by frequent reports of how much pain was being experienced.
Results are congruent with Miller and Bowers’ dissociative control model.
Wagner’s ironic process theory is useful. Frequency of pain reporting moderates Ss reports of pain in analgesia. These results challenge the cognitive social model of hypnotic analgesia and support a dissociative control model. Unlike stress inoculation, hypnotic analgesia does not require cognitive effort for high hypnotizable subjects.
1994
Kiernan, Brian; Dane, Joseph R. (1994, October). Hypnoanalgesia reduces new physiologic index of pain, the R-III Index, but the role of hypnotic susceptibility remains unclear. [Paper] Presented at the annual meeting of the Society for Clinical and Experimental Hypnosis, San Francisco.
NOTES 1:
Stimulated by work of Basil Finer, and following upon the Neodissociation theory of Hilgard; pain is registered by the body but dissociation that produces analgesia is a function of higher brain centers.
Could hypnotic analgesia be mediated lower, at the level of the spinal cord? Gate at dorsal horn could be open or shut; subject to descending modulation. Is hypnosis involved in descending modulation of activity in the dorsal horn?
Hypothesis: reduced pain intensity would be associated with reduced activity at dorsal horn. From Price & Barber, we wanted to look at affect and intensity aspects of pain. Polysynaptic reflex, R-III, latency consistent with conduction velocity (when hand touches a hot stove); even with severed spinal cord injury we still demonstrate the reflex. The magnitude of reflex is linearly related to the pain sensation. The stronger the electrical pulse, the greater the magnitude of the reflex. Magnitude of reflex is linearly related to subjective pain. It is an index of nociceptive activity.
Procedure: Evoke reflex with electrical stimulus at ankle; measure signal at muscle with EMG. We anticipated that at dorsal horn, descending modulation would dampen signal.
15 healthy volunteers. Sural nerve was stimulated. R III reflex measured via EMG response. Used the visual analogue scale (VAS) to assess pain.
1993
Council, James R.; Grant, Debora L. (1993, October). Context effects: They’re not just for hypnosis anymore. [Paper] Presented at the annual meeting of the Society for Clinical and Experimental Hypnosis, Arlington Heights, IL.
NOTES
Context effects in Absorption research are found in correlations, not in mean differences. Original paper has been replicated and yet results are not always significant. Now we are trying to generalize the effect to other areas: an individually administered measure will influence other measures made in the same session.
Other tests that correlate with hypnosis are studied with 2 x 2 design, enabling order effects and same vs separate contexts to be studied. Or two tests are administered at two points in time, with “bridges” between the two sessions (e.g. same experimenter, same consent forms, etc.) As one adds more and more bridging cues, the correlation of Absorption with other Tellegen MPQ subscales increases.
Same context assessment increases correlation between hypnotizability and 6-8 other scales; with childhood trauma scale when trauma scale is administered first; with beliefs in paranormal phenomena when the measure is related to an adjustment scale. The same inflation of correlations was found in Beck Depression scale research.
These results are of concern because we may have to re-do a lot of personality research that suggested correlation between personality test variables, as the correlations may be inflated by the effects of testing in the same context.
Farvolden, Peter; Bowers, Kenneth S.; Woody, Erik Z. (1993, October). Hypnotic amnesia: Avoiding the ‘Intentional Loop’. [Paper] Presented at the annual meeting of the Society for Clinical and Experimental Hypnosis, Arlington Heights, IL
NOTES 1:
The social cognitive view is that Ss actively try to forget and fool themselves, making an attributional error. Davidson & Bowers say (in neo-dissociation theory) the information is temporarily unconscious–like forgetting a friend’s name at a cocktail party. Executive initiative, effort, and control are bypassed.
We used heart rate as indicator of cognitive effort. For highs there should be little increase in heart rate. 20 lows and 20 highs who passed amnesia item on Waterloo-C were used. Post-experimentally we asked them what they were doing following the suggestion of amnesia, and had judges evaluate the degree of effort.
Frischholz, Edward J. (1993, October). The many roles of context in clinical and experimental hypnosis. [Paper] Presented at the annual meeting of the Society for Clinical and Experimental Hypnosis, Arlington Heights, IL.
NOTES 1:
There are two potential sources of dissociation: 1. Person Effect – genetic factors, personality types 2. Situation Effect – situations like environmental causes, contextually dependent
Person Effects and Hypnotizability. Morgan (1973 Journal of Abnormal Psychology) Intraclass correlation determines heritability index: 62% of score is accounted for by genetic factors (though the twins were not reared apart, so family influences also were present). Piccione’s research demonstrated long-term stability for hypnotizability scores; 25 years’ test-retest r = .71, N = 50
Situational Effects and Hypnotizability. Norman Katz (1979) varied context before giving the Stanford Form C for a second time (sleep/trance induction, social learning induction, social learning relaxation induction). The latter two inductions showed significant gains of 3.33 and 2.87 on the scale, compared to .80.
Context effects must always be placed in perspective. When reanalyzing Katz with ANOVA, according to the recommendation of Cronbach for change score analysis, situation accounts for 17% of effect while person effect accounts for 49% (See Spiegel & Frischholz, 1992.)
Dixon, Michael; Laurence, Jean-Roch (1992). Two hundred years of hypnosis research: Questions resolved? Questions unanswered!. In Fromm,
Erika; Nash, Michael R. (Ed.), Contemporary hypnosis research (pp. 34-66). New York: Guilford Press.
NOTES
These notes summarize only that part of the chapter concerning nonvoluntary behavior (pp 38-39; 58-61).
The concept of ‘nonvolition’ has been and continues to be an important issue in hypnosis research. The concept pertains to the “subjective report that the hypnotic suggestion is enacted without the subject’s conscious and willful participation” (p. 38). When hypnosis was attributed to a magnetic fluid, in the days of Mesmer, the issue did not arise (because of course a person would not have control over something that happened to them physically). However, when hypnosis came to be considered a psychological phenomenon, the issue of how a behavior could be the result of motivated action and yet not perceived as being under conscious influence became important. In 1819 Faria wrote that the nonvolition paradox is due to the hypnotized subject’s tendency to misattribute the source or reason for one’s behaviors; he noted that successful suggestions depended upon the subject falsely attributing to the hypnotist the power to influence them. From that point forward, circular reasoning was used to state that one is hypnotized if one experiences their behavior as nonvolitional, and nonvolitional behavior signifies that a person is hypnotized.
“The observation of the seemingly complete automaticity of response in the highly hypnotizable subject led Liebeault in his 1866 book (followed later on by Bernheim and Liegeois) to describe these subjects as ‘puppets’ in the hands of the hypnotist. This was a quite unfortunate statement, since it would lead to one of the fiercest legal debates surrounding the use of hypnosis in the last 20 years of the 19th century (Laurence & Perry, 1988). …
“The most prominent author (if not the only one) who attempted to tackle this difficult question was Pierre Janet, who would make the investigation of automatisms the basis of his theory of hypnosis, rather than suggestion or suggestibility. This theoretical orientation is best exemplified by his concept of desagregation psychologique seen in some psychopathologies, or the carrying out of a posthypnotic suggestion in the normal individual (Janet, 1889; see also Ellenberger, 1970; Perry & Laurence, 1984; Prevost, 1973). Nonetheless, until the end of the 19th century, and for a good part of the 20th century, these reports of nonvolition were thought to be the end result of some neurological changes happening during hypnosis–an idea that has not been substantiated by contemporary research.” (pp 38-39)
Reports of nonvolition are explained as due to dissociation by Hilgard, or as the results of misattributing the origins of behaviors and experiences by Spanos and by Lynn. Neodissociationists like Hilgard regard misattribution to be a cognitive alteration, mainly an internal triggering mechanism, while social psychologists like Spanos and Lynn regard the misattribution to be the results of situational demands and therefore an external triggering mechanism.
“Regardless of one’s preferred metaphor, the issue of nonvolitional reports remains at the core of an integrated view of hypnosis and hypnotizability. The question remains as follows: By which mechanisms does this occur, and how can we predict a priori who will report involuntariness and under what circumstances? Whereas dissociationists have emphasized general cognitive mechanisms and de-emphasized situational factors, social- psychological theorists have emphasized situational variables and de-emphasized individual differences. Given the limitations of both approaches, emphasis will have to be placed not on their continued separation but on their integration, as more and more investigations demonstrate that they clearly interact with each other (see, e.g., Nadon, Laurence, & Perry, 1991).” (p. 60)
“At the height of the confrontation between the two French schools, hypnosis found its way into the legal arena. Following a series of criminal cases in which hypnosis had been allegedly involved, the two schools once again found themselves on opposite sides of the fence. For La Salpetriere, only those who had a propensity toward criminality (and hystericals were prime candidates) could be the victims of hypnosis. For the Nancy school, in highly responsive individuals suggestions could lead to criminal behavior. Unfortunately for the Nancy school, it soon became evident that the concept of suggestion was not sufficient in explaining the questions raised by the courts, and Bernheim was forced to recognize that in cases where suggestions had played a role, other dispositional and situational factors were probably more important in the genesis of the reprehensible behaviors. His espousing a too extreme position meant that the baby was thrown out with the bathwater. History may indicate that the same fate is now awaiting contemporary theoretical positions that adopt an extreme stance vis-a-vis the phenomenon of hypnosis” (p. 61).
1992
Frischholz, Edward (1992, October). The dimensionality of hypnotic performance. [Paper] Presented at the annual meeting of the Society for Clinical and Experimental Hypnosis, Arlington, VA.
NOTES
A 1985 article by Balthazar & Woody in Psychological Bulletin is the best I have read on this topic, and on how factor analysis can be used fruitfully.
Many people using the same data sets have arrived at difference conclusions. My results are based on two data sets: Balthazar & Woody’s, in which they created a unidimensional scale. (If you factor analyze a simplex matrix you obtain a 3 factor matrix; yet you knew it was unidimensional. They pointed out the 2nd factor correlated with item difficulty, and the 3rd factor had a U-shaped correlation with item difficulty.)
Factor analysis may not be best way to demonstrate unidimensionality.
I decided to use non metric multidimensional analysis to confirm unidimension. By this, Form A appears to be multidimensional. The same holds true for Stanford Form C scale.
Interpretability of the different dimensions? I agree with Dr. Stone: unidimensions are better for interpreting tests. But you should start out by constructing one in the first place.
I argue that Form C is unidimensional, because the items were selected by using item/full score correlations, hence a first component was built into it. But what does the scale measure? The only way to know is to correlate it with external measures, like Woody does. There are no studies using factor analysis showing that different factors on hypnotizability tests have different correlations with external measures (e.g. Factor 1 doesn’t correlate differently with Absorption than Factor 3).
We might better start with a theory if we are going to construct new hypnotizability scales. Don’t just use item total correlations. It would be better to find items representing different dimensions, scale the items, then correlate them with different external referents.
Then when we do collect data, make sure the items are unidimensional representations.
Third, we should appropriately validate these dimensions.
Garssen, Bert; de Ruiter, Corine; Van Dyck, Richard (1992). Breathing retraining: A rational placebo?. Clinical Psychology Review, 12, 141-153.
Breathing retraining of patients with Hyperventilation Syndrome (HVS) and/or panic disorder is discussed to evaluate its clinical effectiveness and to examine the mechanism that mediates its effect. In relation to this theoretical question, the validity of HVS as a scientific model is discussed an is deemed insufficient. It is concluded that breathing retraining and related procedures are therapeutically effective, but probably due to principles other than originally proposed, namely decreasing the tendency to hyperventilate. An alternative principle is the induction of a relaxation response, presenting a credible explanation for the threatening symptoms, giving a distracting task to practice when panic may occur, and promoting a feeling of control.
NOTES
Goal of treatment is to (1) reduce respiratory rate, and (2) cognitive reattribution of physical symptoms to hyperventilation instead of other more catastrophic causes. Reviews a number of studies, mostly small sample, including panic disorder studies, and concludes that the majority point to a therapeutic effect of breathing retraining and cognitive reattribution of physical symptoms to hyperventilation for patients suffering HVS and the closely related panic disorder with or without agoraphobia. However, the _specificity_ of these techniques for HVS is questionable. Vlaander-van der Giessen (1986) found relaxation training just as effective as breathing retraining; and Hibbert & Chan (1989) found breathing retraining equally effective as a placebo treatment, and not more effective with patients who had recognized symptoms at a hyperventilation provocation test than with those who had not.
Hajek, P.; Jakoubek, B.; Kyhos, K.; Radio, T. (1992). Increase in cutaneous temperature induced by hypnotic suggestion of pain. Perceptual and Motor Skills, 74, 737-738.
Eight patients with atopic eczema and six healthy subjects were given hypnotic suggestion to feel pain in the upper part of the back and in one case on the palm. An average local increase in skin temperature of 0.6 degrees centigrade (detected by thermovision) occurred under this condition. For some patients cutaneous pain threshold was increased before the experiment by means of repetitive hypnotic suggestion of analgesia. These subjects reported feeling no pain subjectively, but the local change in skin temperature was equal in both cases. The results suggest a central mechanism induced by measuring changes in pain threshold in the skin, which changes are independent of local changes in blood flow. Local pain in the middle of the upper part of the back, and in one subject for comparative purposes in the region of the right palm, was induced during a single hypnotic session by specific suggestion which emphasized a subjective feeling of local pain lasting for 6 minutes. In four of the eczema patients long-lasting cutaneous analgesia was induced before this experiment by a different suggestion which stressed the impossibility of conducting pain form the skin to the brain and which was repeated in ten consecutive hypnotic sessions. The spatial thermal reaction of the skin surface was monitored, with consecutive recordings taken at 20-sec. intervals before and after finishing the hypnotic suggestion of pain. There was a gradual increase in temperature (1.08 degrees Fahrenheit). In the four eczema patients with long-lasting cutaneous analgesia treated equally, the thermal reaction of the skin was similar to that described above although no subjective feeling of pain was reported. These subjects reported feeling only that their skin was getting warmer at the specified place.
Holroyd, Jean (1992). Hypnosis as a methodology in psychological research. In Contemporary hypnosis research (pp. 201-226). New York: Guilford Press.
NOTES
This chapter deals with how the changes brought about by hypnosis (in cognition, behavior, motivation, etc.) may be used in research in other areas of psychology. “The distinction between experimental effects attributable to a personality trait (i.e. hypnotizability), hypnosis context (i.e. an induction), and interaction between the two is particularly important in using hypnosis as a research strategy.
The author discusses suggestibility, imagery enhancement, and changes in the mind-body relationship (immunology, pain, cognitive neuropsychology, attention, learning and memory, and awareness) as they might be employed in social psychology or psychophysiology research. She reviews problems inherent in using hypnosis as part of the research methodology, while noting that hypnosis nevertheless offers new information when introduced into traditional content areas. “For example, in cognitive psychology it has re-introduced the importance of studying experiential aspects of cognition, i.e. I think, I remember, or self reference (Kihlstrom, 1987)” (p. 223).
She concludes, “Hypnosis as a research method will continue to benefit from contributions of radically different theoretical views of hypnotic phenomena. Social- cognitive psychologists have contributed significantly toward unifying the fields of hypnosis research and general experimental psychology. At the same time, advances in neurophysiology and psychosomatic medicine employing hypnosis indicate that there is a role for hypnosis as a research strategy, solely because of its altered-state characteristics. If theoretical physics can reconcile both wave and particle theories of light, it is conceivable that psychology can accommodate both behavioral and state theories of hypnosis” (p. 224).
Isenberg, S. A.; Lehrer, P. M.; Hochron, S. (1992). The effects of suggestion on airways of asthmatic subjects breathing room air as a suggested bronchoconstrictor and bronchodilator. Journal of Psychosomatic Research, 36, 769-776.
Thirty-three asthmatic subjects were told they were receiving, alternately, an inhaled bronchoconstrictor and inhaled bronchodilator, although they actually were only breathing room air. No subjects showed suggestion-produced effects on FEV1, although two (of the 19 on whom FEF50 was measured) showed effects of greater than 20% on measures of maximal midexpiratory flow. The incidence of the effect is smaller than reported previously, possibly because some subjects in previous studies inhaled saline, a mild bronchoconstrictor, and reversal of effect was not required for classification as a reactor. Higher percentages of subjects in this study showed decreased MMEF in response to the ”bronchoconstrictor”, but this appeared to reflect fatigue rather than suggestion effects. However, the fact that the effect occurred in a relatively non-effort-dependent measure suggests that real changes occurred in bronchial caliber, not just in test effort. Suggestion had a significant effect on perception of bronchial changes, but the correlation between actual and perceived changes was minimal. There was an increase in FVC prior to administration of the ”bronchoconstrictor”, possibly reflecting a preparatory response to the expected drug. Correlations among self-report variables suggested the existence of three personality dimensions among our population related to suggestion and asthma: cognitive susceptibility to suggestion of bronchial change; feeling of physical vulnerability; and anxiety. However, there was no significant relationship between airway response to suggested changes and hypnotic susceptibility, as measured by the Harvard Group Scale of Hypnotic Susceptibility
Jacoby, Larry L.; Lindsay, D. Stephen; Toth, Jeffrey P. (1992). Unconscious influences revealed: Attention, awareness, and control. American Psychologist, 47, 802-809.
Recent findings of dissociations between direct and indirect tests of memory and perception have renewed enthusiasm for the study of unconscious processing. The authors argue that such findings are heir to the same problems of interpretation as are earlier evidence of unconscious influences–namely, one cannot eliminate the possibility that conscious processes contaminated the measure of unconscious processes. To solve this problem, the authors define unconscious influences in terms of lack of conscious control and then describe a process dissociation procedure that yields separate quantitative estimates of the concurrent contributions of unconscious and consciously controlled processing to task performance. This technique allows one to go beyond demonstrating the existence of unconscious processes to examine factors that determine their magnitude.
1991
Block, Robert I.; Ghoneim, M. M.; Sum Ping, S. T.; Ali, M. A. (1991). Efficacy of therapeutic suggestions for improved postoperative recovery during general anesthesia. Anesthesiology, 75, 746-755.
There have been claims that the postoperative course of patients may be improved by presentation during general anesthesia of therapeutic suggestions which predict a rapid and comfortable postoperative recovery. This study evaluated the effectiveness of such therapeutic suggestions under double-blind and randomized conditions. A tape recording predicting a smooth recovery during a short postoperative stay without pain, nausea, or vomiting was played during anesthesia to about half the patients (N = 109), while the remaining, control patients were played a blank tape instead (N = 100). The patients were primarily undergoing operations on the fallopian tubes, total abdominal hysterectomy, vertical banding gastroplasty, cholecystectomy, and ovarian cystectomy or myomectomy. The anesthesia methods consisted of either isoflurane with 70% nitrous oxide in oxygen to produce end-tidal concentrations of 1.0, 1.3, or 1.5 MAC; or 70% nitrous oxide in oxygen combined with high or low doses of opioids. Assessments of the efficacy of the therapeutic suggestions in the recovery room and throughout the postoperative hospital stay included: the frequency of administration of analgesic and antiemetic drugs; opioid doses; the incidence of fever; nausea, retching, and vomiting; other gastrointestinal and urinary symptoms; ratings of pain; ratings of anxiety; global ratings of the patients’ physical and psychological recoveries by the patients and their nurses; and length of postoperative hospital stay. There were no meaningful, significant differences in postoperative recovery of patients receiving therapeutic suggestions and controls. These negative results were not likely to be due to insensitivity of the assessments of recovery, as they showed meaningful interrelations among themselves and numerous differences in recovery following different types of surgery. Widespread utilization of therapeutic suggestions as a routine operating room procedure seems premature in the absence of adequate replication of previously published positive studies. (Key words: Anesthesia, depth: Awareness, Memory, Recall, Learning.)
NOTES
Patients ages 19-55 were accepted into the study and they were paid for participation. (Older patients were excluded to guard against memory or hearing problems.) Other criteria for exclusion were: ASA physical status 4 or 5 indicating significant systemic disease, visual or hearing problems, middle ear disease (because it increases probability of nausea and vomiting), if their condition might require heavy sedation, if they were currently taking medication that interferes with memory (e.g. benzodiazepines, if there were intolerance to opioids, or if there were a likelihood of using postoperative pain treatment other than opioids.
The Spielberger State-Trait Anxiety Inventory was administered before surgery. Either suggestions (lasting 6 minutes) or a blank tape were played through headphones, starting 5 minutes after the surgical incision. The tape was played once for the first 59 patients, continuously for the remaining 150 patients. The first 139 patients received additional verbal materials on the tape, for memory tests to test possibility of learning under anesthesia. Operating room sounds were recorded by a tape recorder near the patient’s head, throughout period of unconsciousness (except when tape was being played).
After the first 25% of cases, the team decided that lack of effect on therapeutic suggestions attributable to type of anesthesia did not warrant restriction to a single anesthetic method; also, multiple presentations of the suggestions on tape did not show an effect different from a single presentation.
After the patient regained consciousness and was reoriented, pain, nausea, retching, and vomiting were assessed every 30 minutes. Pain was rated orally on a scale from 1 to 10 in the recovery room, then on visual analogue scales every 2 hours on the day of surgery and the second day, and every 4 hours on subsequent hospital days during waking hours. Variables that were rated by staff every 24 hours included: opioids, other analgesics, antiemetics, nausea, vomiting, retching, presence or absence of nasogastric tube, passage of flatus, bowel movement, fluid intake, solids intake, urination. Temperature was recorded every 4 hours for the first 2 days after surgery, and after that less often. The anxiety measures were repeated on Day 3 postsurgery, as well as self ratings and nurse ratings on physical and psychological recovery. Staff recorded length of postoperative hospital stay and reasons for any delay of discharge. Separate analyses were performed for patients receiving opioids via patient-controlled analgesia (52%) vs traditional administration (48%), but no differences were found for effects of therapeutic suggestions except on postoperative Day 8.
“The inability to detect beneficial effects of therapeutic suggestions probably was not due to insensitivity of the measures of recovery. These measures were sensitive enough to show numerous significant differences in recovery after different types of surgery” (p. 751). The authors supported their contention that the measures were sufficiently sensitive by demonstrating meaningful correlations among the measures themselves; and by demonstrating adequate statistical power for detecting the effects of theoretical interest–at least 1 day in postoperative hospital stay or one half day in fever.
Discussion: The authors note that a recent investigation that found positive results in a double-blind, randomized design with 39 hysterectomy patients (Evans & Richardson, 1988. Improved recovery and reduced postoperative stay after therapeutic suggestions during general anaesthesia. Lancet, 2:491-493) may not have controlled for variables such as presence of malignancy, physical status of patients before surgery, or ethnicity. Authors note that Evans and Richardson observed shorter periods of pyrexia despite there being no relevant suggestions, but no differences in pain intensity, nausea, vomiting, or urinary difficulties despite there being suggestions relating to those symptoms. There also were no differences in mood and anxiety test scores postoperatively for the experimental and control groups.
The authors note that McLintock, Aitken, Downie, & Kenny (Postoperative analgesic requirements in patients exposed to positive intraoperative suggestions. Br M J 301:788-790. 1990) reported a 23% reduction in opioids by patients receiving suggestions, but no reduction in pain, nausea, or vomiting. They contrast the present study with these earlier studies that had obtained positive results.
“We studied patients who had more than one type of surgery to obtain a large sample size and to assess the possibility that beneficial effects of therapeutic suggestions would be restricted to certain types of operations. Had this been the case, interactions of therapeutic suggestions with type of surgery would have been significant in the overall analyses, and follow-up analyses would have indicated that they were attributable to beneficial effects of therapeutic suggestions for certain surgeries. This did not occur. The two types of surgeries involving the largest numbers of patients seemed particularly promising for demonstrating beneficial effects. It has been reported that therapeutic suggestions presented during anesthesia are likely to be less successful with major and extensive surgery. Certainly, surgery on the fallopian tubes and gastric stapling did not involve a great deal of tissue trauma and blood loss. Patients were motivated to have the surgery and to recover quickly; particularly motivated were those having operations on the fallopian tubes, who were very eager to become pregnant, and those having vertical banding gastroplasties, who wanted desperately to lose weight” (pp. 753-754).
“In practice, we observed no beneficial effects of therapeutic suggestions, and there was no hint that anesthesia methods influenced the efficacy of the therapeutic suggestions. Interestingly, anesthetic methods also did not influence learning under anesthesia in the implicit memory tests we have used previously. Patients anesthetized with nitrous oxide and opioids did not differ from those anesthetized only with inhalational agents. In general, implicit or unconscious memory occurs in patients regardless of anesthesia methods or dosages of drugs” (p. 754).
“The few significant effects of therapeutic suggestions in our study did not point toward a beneficial influence of these suggestions. We found, in fact, an increased frequency of retching (but not nausea or vomiting) in the experimental group. The multiple variables examined in this study increased the likelihood of significant differences arising by chance, such that the null hypothesis was rejected when it should have been accepted. This is the way we interpret the effect on retching—i.e., as a type I error. We used in our therapeutic suggestions one negative or exclusionary sentence, ‘You won’t feel nauseous or have to vomit’, among several positive or affirmative statements, e.g., ‘You will enjoy eating, drinking…You will swallow to clear your throat and everything will go one way, straight down. . . The food will taste good….Your stomach will feel fine.’ We do not think that the negative sentence led to paradoxical results. Evans and Richardson (personal communication) used in their therapeutic suggestions a negative sentence (‘You will not feel sick’), which they repeated, yet the reported incidence of nausea and vomiting did not differ between the experimental and control groups” (p. 754).
Dennett, Daniel C. (1991). Consciousness explained. Boston: Little, Brown & Co..
NOTES
Material in this book is relevant to discussions about ‘nonvoluntary’ behavior and (un)conscious experiencing. It combines information from cognitive neuroscience with the philosophy of mind. The author presents a view that consciousness (the ‘mind’) is the consequence of the brain’s activities which give rise to illusions about their own properties. He presents the Multiple Drafts model of consciousness, which reformulates the concept of a ‘stream of consciousness.’ This provides a basis for consideration of concepts central to cognitive neuroscience and phenomena associated with hypnosis, e.g. experiential states and the nature of the self.
The author gives various examples of phenomenology and notes that although these examples are familiar to us, they are totally inaccessible to materialistic science; e.g. the way the sunset looks to someone. He treats people’s descriptions of what they experience as a record of speech acts. Thus, observing and interpreting speech acts, inferring from them the speaker’s inner states, is like a reader who is interpreting a work of fiction. He gives as examples of how one can scientifically study what does not ‘exist’ (a) literary theorists who describe fictional entities, (b) anthropologists who study cultural artifacts like gods and witches, and (c) physicists who study a center of gravity.
In Dennett’s theory, multitrack processes of interpretation of sensory inputs and elaboration of those inputs amounts to a kind of ‘editorial revision’ by the brain. For example in the phi phenomenon a red dot is displayed, followed by a green dot in a different location; the first spot seems to begin moving and then change color in the middle of its illusory passage toward the second location. He points out that awareness of the change in color must occur after seeing the green spot, but one consciously experiences a single spot first red, then red-turning-to-green, finally green. In an example that relates directly to the words used for his theory, he cites contemporary publishing practices, in which several different drafts of an article are in circulation even while the author is revising it. Deciding on some specific moment of brain processing as the moment of consciousness is arbitrary, according to his Multiple Drafts model.
“Visual stimuli evoke trains of events in the cortex that gradually yield discriminations of greater and greater specificity. At different times and different places, various ‘decisions’ or ‘judgments’ are made; more literally, parts of the brain are caused to go into states that discriminate different features, e.g., first mere onset of stimulus, then location, then shape, later color (in a different pathway), later still (apparent) motion, and eventually object recognition. These localized discriminative states transmit effects to other places, contributing to further discriminations, and so forth. The natural but naive question to ask is: ‘Where does it all come together’? The answer is: Nowhere. Some of these distributed contentful states soon die out, leaving no further traces. Others do leave traces, on subsequent verbal reports of experience and memory, on ‘semantic readiness’ and other varieties of perceptual set, on emotional state, behavioral proclivities, and so forth. Some of these effects–for instance, influences on subsequent verbal reports–are at least symptomatic of consciousness. But there is no one place in the brain through which all these causal trains must pass in order to deposit their content ‘in consciousness'” (pp. 134-135).
The author describes the evolution of the brain, along Darwinian lines, and introduces the idea of culture as a repository and transmission medium for innovations (including innovations of consciousness) as a medium of evolution. Through learning, we humans evolve an American or a Japanese brain. Once we have evolved the ‘entrance and exit pathways’ for language, they become ‘parasitized’ by _memes_ (entities that have evolved to thrive in such a niche).
Richard Dawkins coined the term _memes_ to describe the smallest idea elements that replicate themselves reliably (e.g. wheel, alphabet, wearing clothes, right triangle). “The transformation of a human brain by infestations of memes is a major alteration in the competence of that organ” (p. 209).
Dennett discusses the similarities and dissimilarities of brains and computers. He suggests that human minds are like serial virtual machines implemented on parallel processing hardware. The stream of consciousness results from our rehearsal of brief experiences, to commit them to memory; language then permits us to describe to ourselves the process of thinking which leads to judgement and action.
The author’s discussion of how a verbal expression evolves and becomes manifest is related to how so-called intentional action occurs. [This relates to discussions of nonvoluntary actions in hypnosis.] We assume that because our actions make sense, they are the product of serial reasoning. However, there are multiple channels “in which specialist circuits try, in parallel pandemoniums, to do their various things … (pp. 253- 254). Bernard Baars has suggested “that consciousness is accomplished by a ‘distributed society of specialists that is equipped with a working memory, called a _global workspace_, whose contents can be broadcast to the system as a whole (p. 42)'” (p. 257). Dennett states that there is no line dividing the events that are definitely in consciousness from those that are outside consciousness. He urges scientists to forgo the concept of the ‘inner observer’ implied by Cartesian materialism.
Examples of perception that is unaccompanied by consciousness include blindsight (in which the subject does better than chance on visual tests but denies consciousness, and the denials are given credence by neurological evidence of brain damage) and hysterical blindness, which is given less credence because subjects often use the visually provided information in ways blindsight Ss do not. Other behaviors not controlled by conscious thought include blinking when things approach the eye, walking without falling over, regulating our body temperature, adjusting our metabolism, etc. “If I am trying to see a bird that I hear, and stare at the spot but do not distinguish the bird from its background, can I say that it is present in the background of my (visual) consciousness or not?” (p. 336).
The author maintains that if an event doesn’t linger and the person is unable to identify and reidentify the effect, it cannot be reported. But such reportability can be improved, as with training the palate of wine tasters. Often, however, we continue disregarding stimuli that impinge on us. There are minor oversights, such as our ‘blind spots’ or proof reading errors, and major oversights such as a brain-damaged patient’s hemi-neglect. In the Multiple Drafts theory, the Observer is replaced by ‘coalitions of specialists’ that are distributed around in the brain, distributed in both time and space.
Though discrimination or discernment happens, there is no one Discerner doing the work. However, Dennett takes the middle ground on the question of whether a self exists: it is simply a creation like the nest of the Bower bird, or the organized colony of termite ants. “So wonderful is the organization of a termite colony that it seemed to some observers that each termite colony had to have a soul (Marais, 1937). We now understand that its organization is simply the result of a million semi-independent little agents, each itself an automaton, doing its thing. So wonderful is the organization of a human self that to many observers it has seemed that each human being had a soul, too: a benevolent Dictator ruling from Headquarters” (p. 416). The sense of self is a creation, like a physicist’s center of gravity.
Thus, multiple personality disorder is viewed as a self that has gaps; and our sense of self might include different aspects from one year to the other. Hence, “selves are not independently existing soul-pearls, but artifacts of the social processes that create us, and, like other such artifacts, subject to sudden shifts in status. The only ‘momentum’ that accrues to the trajectory of a self, or a club, is the stability imparted to it by the web of beliefs that constitute it, and when those beliefs lapse, it lapses, either permanently or temporarily” (p. 423).
Finally, the author has an extensive discussion of the concepts of ‘qualia’ and of ‘epiphenomena’ and seems to have little use for either term in trying to understand Mind.
Hasher, L.; Stoltzfus, E. R.; Zacks, R. T.; Rypma, B. (1991). Age and inhibition. Journal of Experimental Psychology: Learning, Memory, and Cognition, 17 (1), 163-169.
Two experiments assess adult age differences in the extent of inhibition or negative priming generated in a selective-attention task. Younger adults consistently demonstrated negative priming effects; they were slower to name a letter on a current trial that had served as a distractor on the previous trial relative to one that had not occurred on the previous trial. Whether or not inhibition dissipated when the response to stimulus interval was lengthened from 500 ms in Experiment 1 to 1,200 ms in Experiment 2 depended upon whether young subjects were aware of the patterns across trial types. Older adults did not show inhibition at either interval. The age effects are interpreted within the Hasher-Zacks (1988) framework, which proposes inhibition as a central mechanism determining the contents of working memory and consequently influencing a wide array of cognitive functions.
Arendt-Nielsen, Lars; Zachariae, Robert; Bjerring, Peter (1990). Quantitative evaluation of hypnotically suggested hyperaesthesia and analgesia by painful laser stimulation. Pain, 42, 243-251.
NOTES
Sensory and pain thresholds to laser stimulation were determined, and the laser-pain evoked brain potentials were measured for 8 highly hypnotizable (Harvard Scores 10-11) student volunteers in 3 conditions: (1) waking, (2) suggestion of hyperaesthesia during hypnosis, (3) suggestion of analgesia during hypnosis.
The investigators used a laser beam 3 mm in diameter, with a 200 msec stimulus duration; the same area (but different points within the area) was used for consecutive stimulations. Ss were otherwise maintained in low stimulus conditions so they would not have visual or auditory cues about laser beam onset; they wore goggles, had eyes shut, and had earphones on. Sensory threshold was defined as warmth; pain threshold was defined as a distinct sharp pin prick.
The laser intensity used for stimulation corresponded to strong pain. Interstimulus intervals averaged 15 sec (but were randomly varied between 10-20 sec). Sensory and pain thresholds as well as two evoked potential measurements were taken during waking , hypnotized hyperaesthesia, and hypnotized analgesia conditions in a single 1 1/2 hour session.
The evoked potential component of interest was the negative complex N1 with latency of 300 msec; amplitude (P1=N1-P2) and latency of this complex (N1) were measured. EEG epochs contaminated by eye movement were omitted from analysis.
The standardized induction and deepening of hypnosis required 15-20 minutes; then the suggestion was given that Ss could alter their perception of stimuli such as pain. Hyperaesthesia suggestions were to imagine the right hand was in very hot water, then taken out but still very red, hot, sensitive so that even the vaguest stimulus would be detectable and unpleasant. They were told that they would receive a series of painful but tolerable stimuli, and to raise the left index finger if they could just perceive a laser pulse (sensory threshold), and again if they felt pricking pain (pain threshold).
Suggestions for analgesia were to imagine that their right hand was placed on their chest, and that their ‘former right hand’ was no longer their own but was made of some heavy and completely insensitive material like wood or stone. Sensory and pain threshold measures were then taken. During the evoked potential measurement period they received continuous suggestions of analgesia. They also were told to relax and imagine they were in a pleasant place, ignoring everything except the pleasant, relaxed feelings and imagining pleasant sights, sounds, feelings and the imagined place. They were told that though they would receive stimuli, they probably would be able to ignore the stimuli completely.
Results were as follows.
1. In the hypnotic hyperaesthesia condition, sensory and pain thresholds decreased significantly by 47% and 48%, respectively. Three Ss reacted to laser intensities far below what normally can be perceived in the waking state. [The authors ran a separate small control experiment to make sure that the Subjects were not using any other cues, but mention the possibility of light-sensitive skin reacting to the blue laser light, creating evoked potentials.]
2. In the hypnotic analgesia condition, sensory and pain thresholds increased by 316% and 190%, respectively. 7 of 8 Ss did not even respond to pain threshold when the laser intensity was increased to the noxious level of 3W, which is the level at which tissue damage can occur.
3. Pain-related evoked potentials. Amplitude of the first pain-related potential was increased significantly by 14% in the hyperaesthesia condition and reduced significantly by 31% in the analgesia condition. Changes in the evoked potentials were considered minor however compared to those observed for thresholds, which are subjective response measures. Even in Subjects who reported complete analgesia, the experimenters observed the laser pain evoked responses. There were no differences in latencies of the first pain-related potentials for the three conditions (indicating that peripheral and central afferent conduction velocities were the same).
Discussion. “There has been some dispute concerning the experimental design and the reliability of the data obtained in studies dealing with hypnotic suggested analgesia [Spanos & Chaves, 1970]. In our design 2 ‘opposite’ conditions were induced, and the 2 inductions gave ‘opposite’ results.
“The experience of pain can be significantly altered by suggestions of analgesia, which is in accordance with a number of other studies (for review see [Barber & Adrian, 1982; Hilgard & Hilgard, 1975]). The finding that suggestions of hyperaesthesia can decrease the sensory and pain thresholds and increase the amplitude of the pain evoked potential is a new observation. Since synchronized auditory and visual stimuli from the laser were blocked, and the stimulus was given at random intervals, the changes might be induced by the hypnotic suggestions” (p. 247).
The authors discuss their results in terms of (1) four pain modulation systems (neural/opiate, hormonal/opiate, neural/non-opiate, and hormonal/non-opiate) and (2) focusing and defocusing attention. Because in their pilot study it was necessary to give suggestions continually in order to affect the laser evoked potentials, they conclude that endogenous substances or hormonal/non-opiates would play a minor role, if any, in hypnotic analgesia. (Price and Barber [25] had also found it important to give suggestions continuously.)
On the other hand, “event-related potentials [7, 26] and pain-related potentials have, previously, been shown to be sensitive to focused and de-focused attention. Recently, Miltner et al. [23] showed the influence of attention on the late pain-related component of potentials, evoked by painful intracutaneous electrical stimulation. The degree to which the subject paid attention to the painful stimulus had a powerful effect on the pain-related complex. When subjects ignored the pain, it was still possible to record the pain-related complex although all the subjects consistently reported less or no pain. In wakeful subjects where cutaneous pain was abolished by lignocaine infiltration, the pain-related evoked potentials were abolished [4]. In our study, we could also record evoked potentials although the subject subjectively did not feel pain. The reason might be that the S acted as if there was full analgesia to the stimuli, in order to satisfy the hypnotist. During suggested hyperaesthesia the thresholds declined below what normally could be perceived in the wakeful state. The volunteers could, therefore, not act hypersensitive, so something did happen.
“The discrepancy in subjective and objective responses might, however, be useful when investigating levels of the neuroaxis at which hypnosis might work” (pp. 248-249).
The authors note that this laser induced pain and the tooth pulp stimulation pain of Mayer & Barber both use the A-delta fibers. Barber & Mayer found it impossible to elicit pain within the output range of the stimulator (up to 150 microA) and reached maximal intensity for all volunteers during suggested analgesia. Using cutaneous laser stimulation the authors found that the skin damage level (3W) could be reached in 7 of 8 volunteers without any reaction of pain.
During the hyperaesthesia condition the sensory threshold was sometimes lower than can be detected in the waking state. Although some researchers have suggested that red light from a helium-neon laser might activate cutaneous photosensitive receptors and thereby elicit brain potentials, the authors were unable to elicit potentials in waking Subjects using their blue and green argon laser light with below sensory threshold intensity.
The authors also note that previous attempts to use physiological correlates of pain such as heart rate, blood pressure, respiration, and galvanic skin response have yielded confusing results. The physiological indicators are present even when Subjects report analgesia, leading some investigators to conclude that the subjective reports are due to illusion [Sutcliffe, 1961], compliance [Wagstaff, 1986], or a placebo induced by the hypnosis context [Wagstaff, 1986]. “These confusing results lead to the conclusion that both the traditional methods used for induction of pain and the monitored physiological responses have been unsatisfactory. The present study has sought to eliminate some of the methodological difficulties by (1) using brief well-defined argon laser stimuli which in awake volunteers induce very stable perceptions between trials [Arendt-Nielsen & Bjerring, 1988], and (2) recording psychophysical thresholds and objective parameters quantitatively related to the intensity of the pain perceived (1, 3)” (p. 249).
1990
Bartis, Scott P.; Zamansky, Harold S. (1990). Cognitive strategies in hypnosis: Toward resolving the hypnotic conflict. International Journal of Clinical and Experimental Hypnosis, 38, 168-182.
Two experiments were carried out to assess the relative contributions of dissociation and absorption as cognitive strategies employed by high and low hypnotizability Ss in responding successfully to hypnotic suggestions. Of special interest was the manner in which Ss deal with conflicting information typically inherent in hypnotic suggestions. In the first experiment, Ss rated their attentional focus and the involuntariness of their experience after responding to a number of hypnotic suggestions administered in the usual manner. In the second experiment, the level of conflict was varied by instructing some Ss to imagine a circumstance that was congruent and other Ss to imagine a circumstance that was incongruent with the suggested behavioral response. The results of the 2 experiments were consistent in suggesting that, depending upon the nature of the hypnotic suggestion, high hypnotizability Ss are able to employ dissociation or absorption in order to respond successfully. Low hypnotizability Ss, on the other hand, seem to be relatively ineffective dissociators. When the structure of the hypnotic suggestion precludes the use of absorption, the performance of low hypnotizables deteriorates.
Edmonston, William E., Jr.; Moscovitz, Harry C. (1990). Hypnosis and lateralized brain functions. International Journal of Clinical and Experimental Hypnosis, 38, 70-84.
Bilateral EEG measures were obtained on 16 high hypnotizable Ss (scores of >8 on the Harvard Group Scale of Hypnotic Susceptibility, Form A, Shor & E. Orne, 1962), while performing hemisphere-specific tasks during hypnosis and a no-hypnosis control condition. Conditions and tasks were presented in counterbalanced order, and Ss served as their own controls. The data call into question the right hemisphere activation interpretation of lateralized brain function during hypnosis; rather, the data suggest a lack of task appropriate activity during hypnosis. The failure to attend to baseline activity measurements and the use of ratios to evaluate interhemispheric lateralization may contribute to potential misinterpretations of data. It is critical that activity changes of the separate hemispheres be taken into account in the interpetative process.
Hajek, P.; Jakoubek, B.; Radil, T. (1990). Gradual increase in cutaneous threshold induced by repeated hypnosis of healthy individuals and patients with atopic eczema. Perceptual and Motor Skills, 70, 549-550.
NOTES
Cutaneous pain threshold was measured in “time in seconds from onset of heat source of defined size, distance from skin, and temperature, to subjective threshold percept of pain” (p. 549). Used two symmetrical locations on both forearms, at healthy areas of the skin. Ten hypnotic sessions were induced in each S three times weekly, each lasting one hour.
Suggestions were the following type: “The “conduction of switch to the brain is interrupted.” Your “immunologic system will digest the damaged skin cells like a shark.”
Subjects were 14 healthy subjects and 13 patients with atopic eczema treated for years with the usual medications, unsuccessfully or with complications.
There was gradual increase in cutaneous pain threshold across the 10 sessions, especially for the patient group. Control experiments with repeated threshold measurements in repeated sessions without hypnosis showed no changes.
“Time of increases in cutaneous pain threshold was associated with improvement of atopic eczema. Both effects correlated significantly (r = 0.8) with hypnotizability as measured by the Stanford scale” (pp. 549-550).
“In 9 patients without further hypnotic sessions a slow spontaneous decay of the cutaneous pain threshold was observed during a 17-mo. period. Special experiments performed with six repeatedly hypnotized healthy subjects showing increased thresholds did prove, however, that the cumulative analgesic effect could be reduced to control values immediately by using the hypnotic suggestion that the ‘skin sensitivity returns to normal values.’
“These results suggest a close association between hypnosis and activation and/or deactivation of endogenous analgesic systems (irrespectively whether they are of opioid or nonopioid nature)” (p.550)
1989
Brentar, J.; Lynn, Steven J. (1989). ‘Negative’ effects and hypnosis: A critical examination. British Journal of Experimental and Clinical Hypnosis, 6, 75-84.
Reviews evidence concerning if hypnosis is responsible for unwanted or negative posthypnotic effects, concluding that support for this hypothesis is lacking. Many such investigations are either anecdotal reports or are marred by methodological flaws that render the interpretation of posthypnotic experiences problematical. Controlled research has not provided support for the hypothesis that hypnosis per se is responsible for certain subjective changes which accompany it, or that hypnosis is more stressful or anxiety provoking than other common experiences encountered by subjects. Although a small percentage of subjects appear to experience posthypnotic reactions, they are typically fleeting, and the link between hypnotic procedures and negative effects has not been adequately substantiated. Indeed, routine hypnosis is typically harmless and is perceived by many subjects as a pleasant, positive experience.
Buss, A. H. (1989). Personality as traits. American Psychologist, 44, 1378-1388.