Can't sleep in a new place? Your left brain might be why

Over the course of three experiments on 35 young, healthyvolunteers, researchers measured brain activity during twoconsecutive nights of sleep. They consistently found that partof the left side of the brain remained more active than theright side only on the first night, specifically during deepslow-wave sleep.

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While this may be bad news for business travellers whoregularly make brief overnight trips, it may not be astroublesome for people who go away for longer periods of time,Sasaki added by email.

Differences in alertness

When they stimulated the left hemisphere with irregularbeeping sounds in the right ear during deep sleep on the firstnight, that prompted significantly greater likelihood of wakingand faster action upon waking, than if sounds were played in theleft ear to stimulate the right hemisphere.

On the second night, there wasn't any difference inreactions to tests between the left and right hemispheres, evenduring deep sleep.

While it's possible that the findings may explain poor sleepamong frequent travellers, the study wasn't designed to testwhether these "first night effects" continue to happen to peopleevery time they hit the road, said Patrick Finan, a psychiatryand behavioural health researcher at Johns Hopkins UniversitySchool of Medicine in Baltimore.

"Any clinical implications would be speculative at themoment," Finan added. "However, the level of specificityprovided by these analyses could be an important first step inunderstanding who might be at risk for sleep disorders likeinsomnia, which is thought to be driven in many patients bychronic hypervigilance."