Differential Effects of Biofeedback Input on Lowering Frontalis Electromyographic Levels in Right and Left Handers

• Main Author: Walker, Kenneth N. (Kenneth Neal)
• Other Authors: Harrell, Ernest H.
• Format: Others
• Language: English
• Published: University of North Texas 1990
• Subjects: handedness; electromyographic biofeedback; biological control systems; cerebral asymmetry; left and right hemisphere (brain); Biological control systems.; Left- and right-handedness > Psychological aspects.
• Online Access: https://digital.library.unt.edu/ark:/67531/metadc331405/

This investigation was an attempt to replicate and expand previous research which suggested that laterality of electromyographic biofeedback input had a significant effect in lowering frontalis muscle activity. In 1984 Ginn and Harrell conducted a study in which they reported that subjects receiving left ear only audio biofeedback had significantly greater reductions in frontalis muscle activity than those receiving right ear only or both ear feedback. This study was limited to one biofeedback session and subjects were selected based on demonstration of right hand/ear dominance. The purpose of the present study was to determine whether the left ear effect reported by Ginn and Harrell could be replicated. Furthermore, the current investigation sought to extend the previous finding to left handed subjects and explore the stability of the effect, if found, by adding a second biofeedback session. Subjects were 96 students recruited from undergraduate psychology classes. They were screened for handedness by the Edinburgh Handedness Inventory which resulted in identification of 48 right handers and 48 left handers. Subjects were randomly assigned to one of four groups consisting of left ear feedback, right ear feedback, both ears feedback, and controls. This resulted in eight conditions. Analysis of variance of microvolt changes from baseline found no statistically significant differences between groups. An examination of the rank order of the data reveal a left ear group performance in the same direction as those reported by Ginn and Harrell (1984).