Controlled group designs in biofeedback research: ask, "What does the control group control for?"

Area of Science:

• Psychophysiology
• Behavioral Medicine
• Rehabilitation Science

Background:

• Biofeedback is utilized for skeletal muscular relaxation, but its specific efficacy is debated.
• Existing research often lacks rigorous control groups, leading to potential confounding variables.
• The precise mechanisms by which biofeedback influences muscle relaxation require further elucidation through controlled studies.

Purpose of the Study:

• To critically review the existing literature on biofeedback for skeletal muscular relaxation.
• To identify deficiencies in control procedures used in biofeedback outcome research.
• To discuss the strengths and weaknesses of various controlled group designs for biofeedback studies.

Main Methods:

• Systematic review of extant literature on biofeedback and skeletal muscular relaxation.
• Analysis of control procedures in published biofeedback studies, including attention placebo, pseudofeedback, and altered contingency designs.
• Evaluation of the adequacy of control procedures in managing confounding variables and placebo effects.

Main Results:

• The literature on biofeedback for skeletal muscular relaxation is deficient in properly controlled group outcome research.
• Commonly used control procedures inadequately control for confounding variables and placebo effects.
• Many studies failed to assess the credibility of control procedures or subjects' ability to discriminate feedback contingencies.
• Control procedures are not inert or equivalent in their effects on control group behavior.

Conclusions:

• Controlled group outcome designs should be considered the minimum standard for biofeedback research.
• Improvements in control procedures are necessary to accurately assess the specific effects of biofeedback.
• Further research is needed to establish the efficacy and mechanisms of biofeedback in promoting skeletal muscular relaxation.