I wanna hold your hand ...

Lying in the jaws of an M.R.I. scanning machine and knowing that they would periodically receive a mild electric shock to an ankle, the women were noticeably apprehensive. Brain images showed peaks of activation in regions involved in anticipating pain, heightening physical arousal and regulating negative emotions, among other systems.

But the moment that they felt their husbands' hands — the men reached into the imaging machine — each woman's activity level plunged in all the regions gearing up for the threat. A stranger's hand also provided some comfort, though less so.

From this story in the New York Times.