Maxwell I. Gwynn

Effects of Suggestion and Distraction on Reported Pain in Subjects High and Low on Hypnotic Susceptibility

Subjects high and low in hypnotic susceptibility immersed an arm in ice water on two separate trials Within susceptibility levels, subjects were randomly assigned to three groups, with an equal number (14 highs, 14 lows) in each group. Between trials those in one group were administered a suggestion to imagine their hand as numb and insensitive, those in a second group practiced a distraction task to be used during the second trial (shadowing words), and those in a third group (controls) received no special instructions The suggestion significantly lowered rated pain in high but not in low susceptibles Contrary to dissociation accounts of hypnotic susceptibility and suggested analgesia, low-susceptible shadowers showed as much reduction m rated pam as high susceptibles given suggestion. Findings are discussed in terms of the social psychology of the experimental pain assessment situation

Are hypnotically induced pseudomemories resistant to cross-examination?

Two experiments examined the effects of hypnotic procedures in response to interrogation and crossexamination in subjects who viewed a simulated robbery. Experiment 1 found that hypnotic and nonhypnotic leading interrogations were equally likely to produce misattributions and misidentification of mug shots. Moreover, under cross-examination subjects who had been given an hypnotic interrogation and those given nonhypnotic interrogations were equally likely to disavow their earlier misattributions and misidentifications. In both hypnotic and nonhypnotic treatments high hypnotizables were more likely than low hypnotizables to misattribute characteristics during interrogation and to disavow earlier misattributions during cross-examination. In Experiment 2 high hypnotizables given a cross-examination that legitimated their earlier errors as honest mistakes and that enabled them to disavow earlier testimony without discrediting themselves (hidden observer treatment) showed the highest and most consistent rates of disavowel. A stringent cross-examination that implied that subjects had been careless or dishonest during interrogation produced the lowest rates of disavowel.

Hypnotic interrogation, pretrial preparation, and witness testimony during direct and cross-examination

Subjects who witnessed a videotaped shooting were interrogated immediately after viewing the film and again several days later. Before their second interrogation half of the subjects received hypnotic suggestions for enhanced recognition. Hypnotic and nonhypnotic subjects failed to differ in the accuracy with which they identified a mugshot of the offender, but hypnotic subjects placed more confidence in their misidentifications than did nonhypnotic subjects. In a third session, subjects who had identified a mugshot returned to be examined and cross-examined in a mock courtroom setting. Before direct examination, half the subjects underwent pretrial preparation aimed at building confidence. When coupled with pretrial preparation, hypnotic interrogation led subjects to express relatively high certainty in their mugshot identification while testifying. Nevertheless, hypnotic interrogation did not deter witnesses from disavowing their testimony (i.e., breaking down) during cross-examination. In contrast, pretrial preparation induced substantial resistance to breakdown during cross-examination. Implications are discussed.

The Effects of Expert Testimony concerning Rape on the Verdicts and Beliefs of Mock Jurors

Mock jurors heard one of four versions of a ‘date rape’ case and deliberated, in small groups, to a verdict. Exposure to the direct examination of an expert who testified about rape myths undermined belief in the defendants testimony that sex with the complainant had been consensual, and increased the frequency of guilty votes. However, exposure to the experts cross-examination reversed the effects of the direct examination on the frequency of guilty votes. Women jurors disbelieved the defendant and voted him guilty to a greater extent than male jurors, while in both sexes profeminist attitudes correlated with disbelief in the defendants testimony but failed to correlate significantly with final verdicts. Implications are discussed.

The role of compliance in hypnotic and nonhypnotic analgesia

We modified the standard procedure for administering finger pressure pain in order to assess the extent to which subjects biased their reports of pain reduction when exposed to compliance-inducing instructions. Experiment 1 used only highly hypnotizable subjects and found that compliance-induced reductions in reported pain were about half as large as the reported reductions produced by hypnotic analgesia suggestions. Experiment 2 used low as well as high hypnotizables and administered hypnotic or nonhypnotic analgesia instructions and compliance instructions to the same subjects on separate pain trials. Reported pain reductions produced by hypnotic and nonhypnotic analgesia suggestions and those produced by compliance instructions were substantially and significantly correlated. Furthermore, hypnotizability correlated with compliance-induced reported pain reductions as highly as it correlated with the reported reductions produced by hypnotic analgesia suggestions. Among high hypnotizables (but not low hypnotizables) compliant responding was predicted by social desirability. The findings of both studies indicate that compliance strongly influences the reports of hypnotic and nonhypnotic analgesia proffered by high hypnotizables. The role of compliance in the pain reductions reported by low hypnotizables is less clear-cut.

The Effects of Three Instructional Treatments on Pain Magnitude and Pain Tolerance: Implications for Theories of Hypnotic Analgesia

Between baseline and posttesting on the cold pressor test, subjects were assigned to four treatments: a) hypnotic analgesia, b) brief instructions to “Do whatever you can to reduce pain,” c) stress innoculation, and c) no instruction control. Participants in the three instructional treatments showed significantly greater baseline to posttest decrements in pain magnitude and significantly greater increments in pain tolerance than controls. However, the instructional treatments did not differ significantly from one another in these regards. Pretested hypnotic susceptibility correlated significantly with degree of pain reduction in the hypnotic analgesia treatment but not in the “Do whatever” or stress innoculation treatments. Theoretical implications are discussed.

The Mediating Effects of Expectation on Hypnotic and Nonhypnotic Pain Reduction

High and low hypnotically susceptible subjects were assigned to three treatments and administered a baseline trial and two posttest trials of finger pressure pain. Subjects in one treatment received hypnotic analgesia on both posttest trials while those in a second treatment received hypnotic analgesia before their first posttest trial and waking instructions to “do whatever you can to reduce pain” before their second posttest trial. Controls received their two posttest trials without intervening treatment instructions. During hypnotic analgesia high susceptibles reduced reported pain, increased pain tolerance and rated themselves as more deeply hypnotized than low susceptibles. Low susceptibles reduced pain to a significantly greater degree under waking instruction than under hypnotic analgesia. Importantly, lows given waking instruction reduced pain to the same degree as highs given hypnotic analgesia. These findings underscore the importance of attitudes and expectations in hypnotic pain reduction. However, they are inconsistent with the view that high susceptibles are intrinsically more able than low susceptibles to cognitively control pain.

Functional measurement scales of painful electric shocks

Subjects were required to rate the combined intensities of two factorially paired shocks ranging in intensity from 1 mA through 2, 3, 4, and 5 mA. In Experiment 1, an anchored 1–20-point rating scale was used, and in Experiment 2, one of two scales, 1–15 points or 1–25 points, was provided to the subject. Data from all three conditions were fit by a weighted average model, Rij=wsi+(i−w)sj, where Rijs are mean ratings, si and sj are scale values of the first and second shocks, and w is a weight parameter. The derived psychophysical functions were linear in all three cases, and the slope increases with the number of available categories, in conformity to range-frequency theory. In a third experiment, subjects were divided according to the ratings they gave of pain elicited by the 5-mA shock. The weighted averaging model provided an appropriate integration model for both higher and lower pain raters. Higher raters tended to accord an equal weight to both shocks, whereas lower raters accorded greater weight to the second stimulus. Implications for research on analgesic procedures are discussed.