Biomedical subjects
Publications and source records attributed to I Wickramasekera.
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Changes in the magnitude and direction of physiological measures (EMG, EEG, temperature, etc.) are not strongly related to the reduction of clinical symptoms in biofeedback therapy. Previously, nonspecified perceptual, cognitive, and emotional factors related to threat perception (Wickramasekera, 1979, 1988, 1998) may account for the bulk of the variance in the reduction of clinical symptoms. The mean magnitude of these previously nonspecified or placebo factors is closer to 70% when both the therapist and patient believe in the efficacy of the therapy. This powerful placebo effect is hypothesized to be an elicited conditioned response (Wickramasekera, 1977a, 1977c, 1980, 1985) based on the memory of prior healings. These memories of healing are more resistant to extinction if originally acquired on a partial rather than continuous reinforcement schedule. High and low hypnotic ability in interaction with threat perception (negative affect) is hypothesized to contribute to both the production and reduction of clinical symptoms. High and low hypnotic ability respectively are hypothesized to be related to dysregulation of the sympathetic and parasympathetic arms of the autonomic nervous system. Biofeedback is hypothesized to be most effective for reducing clinical symptoms in people of low to moderate hypnotic ability. For people high in trait hypnotic ability, training in self-hypnosis or other instructional procedures (e.g., autogenic training, progressive muscle relaxation, mediation, CBT, etc.) will produce the most rapid reduction in clinical symptoms.
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We studied 70 morbidly obese patients, candidates for gastric exclusion surgery. We found that their mean absorption score was significantly lower and that their mean neuroticism score significantly higher than a matched control group. These results are consistent with predictions from the High Risk Model of Threat Perception (Wickramasekera, 1979, 1986, 1988, 1993a). People high in neuroticism are hypothesized to be hypersensitive to threat and, therefore, at greater risk for stress related psychobiological disorders. But if they are also low in absorption, they are hypothesized to have poor conscious perception of psychosocial threats and, therefore, they develop a very restricted range of psychosocial methods of coping with such threats. Consequently, lows may be mainly restricted to behavioral methods of coping like feeding and drinking to self-soothe unconscious aversive emotions associated with autonomic dysregulation and elevated parasympathetic tone. Their skeptical, rational, pragmatic cognitive style drives them to perceive medical surgical solutions to weight gain as more credible than psychosocial weight reduction programs.
The high risk model of threat perception predicts that high hypnotizability is a risk factor for trauma-related somatization. It is hypothesized that high hypnotizability can increase experimentally induced threat or negative affect, as measured by skin conductance level, in a linear or dose-response manner. This hypothesized interaction of hypnotic ability and negative affect was found in a consecutive series of 118 adult patients with chronic pain symptoms. Larger increases in skin conductance levels during cognitive threat were significantly related to higher levels of hypnotizability. In addition, individuals with high hypnotizability retained higher skin conductance levels than individuals with low hypnotizability after stress. The clinical implications of the interaction of hypnotizability and negative affect during threat perception and delayed recovery from threat perception are discussed in terms of cognitive mechanisms in the etiology and therapy of trauma-related dissociative disorders.
The electrodermal response to cognitive threat of unhypnotized female patients with somatic symptoms and high on both hypnotic ability and neuroticism (H-H) was found to be significantly higher (p < .01) than that of a matched group of female patients moderate on hypnotic ability and low on neuroticism (M-L). On verbal report the H-H and the M-L groups did not differ, but they were significantly different on a measure of self-deception (L scale) or repression. The above findings are consistent with predictions from the High Risk Model of Threat Perception (HRMTP), which states that people in the H-H group are both chronically and acutely more reactive to threat than the people in the M-L group. This finding may have important theoretical, clinical, and financial implications for the diagnosis, therapy, and prevention of somatization disorders seen in primary medical care.
A model of the placebo response as a conditioned response (CR) is presented and predictions from this model are listed. Through association with active ingredients (UCS), neutral (CS) places, persons, procedures, and things can come to acquire the ability to reduce pain, anxiety, and depressive responses. One major counterintuitive prediction from the model is that therapists who routinely use active ingredients (UCS) or powerful drugs will get stronger placebo effects than those who routinely use "inert" ingredients (CS) or weak drugs. Developmentally, placebo responding appears to involve two successive conditioning stages, which may involve first the left and later the right hemisphere in right-handed subjects. The relationship between placebo responding and hypnotizability is discussed.
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