MRI shows that hand-holding decreases stress
Gwynne D. Koch
The saying “lending a helping hand” takes on another level of meaning, according to a recent study conducted by neuroscientists at the University of Virginia, Charlottesville, and the University of Wisconsin-Madison. With the aim of understanding the effect of soothing social behaviors on neural systems that respond to danger and stress, the researchers used functional MRI to examine how the brains of married women respond to hand-holding while the women are in a threatening situation.
Sixteen women in self-rated highly satisfactory marriages were subjected to the threat of receiving an electric shock to the ankle while holding their husbands’ hands, the hand of an anonymous male experimenter or no hand at all. The scientists selected hand-holding because it is a common nonverbal means of expressing support and affection, and it can be implemented easily in the MRI scanner.
MRI images were acquired while the women viewed on a black background either a red “X” indicating a 20 percent chance of receiving an electric shock or a blue “O” indicating safety. Several hundred images of the whole brain were collected in volumes of 30 4-mm sagittal echo-planar slices with a repetition rate of 2 s and a 30-ms echo time using a GE Signa 3.0-T high-speed MRI device.
Electric shocks of 4 mA and 20 ms in duration were delivered at the end of a 4- to 10-s anticipation period after the viewing of the threat or safety cue. After each of the three trial conditions, women rated their subjective feelings of unpleasantness and agitation. The researchers used Analysis of Functional Neural Images software developed by the National Institutes of Health to reconstruct the data and to analyze activation of neural systems in specific regions of the brain that respond to danger.
The results indicated a significant decrease in activity in neural systems that respond to threat when women were holding their husbands’ hands and a limited attenuation of response when holding a stranger’s hand. Interestingly, the higher the quality of the marriage was rated, the more effective spousal hand-holding was at alleviating responses to threat. The pattern of neural responses was supported by the women’s subjective reports of experience.
Because there is evidence that the effect of hand-holding in attenuating threat response might be more effective in females, the current study involved only women. The investigators are expanding their studies to include men, homosexual couples and couples involved in troubled relationships.
Psychological Science, December 2006, pp. 1032-1039.
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