TESTS show that a man who has a pent-up desire for sex has difficulty hearing, thinking or driving. He also suffers a form of time distortion, where three minutes feels like 15 minutes.

If a woman wants an intelligent decision from a man, she's better off discussing it after sex, when his brain is clear, rather than before.

For a woman, talking can be a crucial part of the build-up to sex because words are all-important to her. Equally, men love to hear women talk about sex.

But the big difference is that, because most men can only do one thing at a time, he can't really talk during sex.

For a man to talk during sex, he needs to switch to his left brain, whereas the woman can do both.

A woman should be aware that, if she talks during sex (not counting mmmms and aaaahs), a man may feel obliged to respond, and the moment can be lost.

Brain scans show that during sex a man is so intent on what he's doing that he's virtuayl deaf.

THE SILENT TREATMENT