Sharing a bed with someone could temporarily reduce your brain power - at least if you are a man - Austrian scientists suggest.
When men spend the night with a bed mate their sleep is disturbed, whether they make love or not, and this impairs their mental ability the next day.
The lack of sleep also increases a man's stress hormone levels.
According to the New Scientist study, women who share a bed fare better because they sleep more deeply.
Sleepless nights
Professor Gerhard Kloesch and colleagues at the University of Vienna studied eight unmarried, childless couples in their 20s.
Each couple was asked to spend 10 nights sleeping together and 10 apart while the scientists assessed their rest patterns with questionnaires and wrist activity monitors.
The next day the couples were asked to perform simple cognitive tests and had their stress hormone levels checked.
Although the men reported they had slept better with a partner, they fared worse in the tests, with their results suggesting they actually had more disturbed sleep.
But women apparently managed to sleep more deeply when they did eventually drop off, since they claimed to be more refreshed than their sleep time suggested.
Their stress hormone levels and mental scores did not suffer to the same extent as the men.
But the women still reported that they had the best sleep when they were alone in bed.
Bed sharing also affected dream recall. Women remembered more after sleeping alone and men recalled best after sex.
Full article:
http://news.bbc.co.uk/2/hi/health/5197440.stm