The More Vivid the Imagination the Better: The Role of the Vividness of Imagination in Vasoconstriction Training and Vasodilatation Training.

Blood volume pulse biofeedback represents an effective non-pharmacological treatment for migraine. However, the underlying mechanisms of blood volume pulse biofeedback are still unclear. This study investigated the influence of vividness of imagination, private body consciousness, perfectionism, and general self-efficacy on physiological (blood volume pulse amplitude) and psychological (session performance rated by participants and by trainers) success. Changes in skin conductance and skin temperature indicating habituation to training context were examined. Forty-five healthy male participants were randomized to four sessions of vasoconstriction training or vasodilatation training. Hierarchical linear models were estimated. Results showed significant changes of session performance rated by participants (UC = 0.62, p < .05), by trainers (UC = 0.52, p < .001), and skin temperature (UC = 0.01, p < .001) over time. A change of blood volume pulse amplitude could not be observed (UC = -0.01, p = .65). Vividness of imagination was highly important for both psychological achievement ratings (UC participants = 1.3, p < .001; UC trainers = 0.29, p < .01). Relations between skin temperature and general self-efficacy or personal standards were small (UC self-efficacy = 0.002, p < .10; UC personal standards = 0.002, p < .05). A time × group interaction regarding trainers' achievement ratings indicated a specific judgement effect. In conclusion, biofeedback trainers should pay attention to their beliefs and participants' vividness of imagination.

[Pilot Study of the Feasibility of a Short Biofeedback Treatment of Chronic Headache in the Outpatient Care System]. / Pilotstudie zur Durchführbarkeit einer Biofeedbackkompaktbehandlung bei chronifizierten Kopfschmerzen in der ambulanten Versorgung.

Introduction: Although biofeedback has been shown to be an effective treatment of tension-type headache and migraine, it has not been well implemented in the outpatient care system yet. Central aims of this randomized controlled pilot study were to examine the feasibility and implementation of a short biofeedback treatment of chronic headache in the outpatient care system, to estimate standardized effect sizes for treatment outcome, and to investigate the influence of expectancies on treatment outcomes. Methods: In this pilot study, the patients (N=18) were diagnosed according to the criteria defined by the International Headache Society and randomized afterwards. Patients received 8-11 sessions of biofeedback (depending on the indication: Electromyography biofeedback, Vasoconstriction-/Vasodilatation training or a combination of both). Outcome assessments took place before and after the biofeedback treatment via questionnaires. Hedges' g was computed based on change scores of treatment expectancies, session performance (patients and therapists), headache-specific self-efficacy (Headache Management Self-efficacy Scale-Short form), headache-related variables (Pain Disability Index, German Pain Coping Questionnaire) and comorbid strain (Hospital Anxiety and Depression Scale). Pearson-correlations were calculated for the relations of change scores. Results: Effect sizes for most of the assessed expectancies and coping were high (g=0.94-1.45). Improvements in the willingness to practice and disability in everyday life were moderate (g=0.40-0.51). The correlations between patients' expectancies and disability or coping were medium (r=- 0,42 - 0.41). Results showed a moderate negative correlation between the patient-rated session performance and depression (r=-0.33). Discussion and Conclusion: The short biofeedback treatment showed a good feasibility and implementation in the outpatient care system, with pilot results indicating effectiveness. The documented associations between patient-rated and therapist-rated expectancies and the treatment outcome emphasize the importance of the assessment of expectancies.