Dr Mirjam Tuk, who led the study, said that the brain's "control signals" were not task specific but result in an "unintentional increase" in control over other tasks. "People are more able to control their impulses for short term pleasures and choose more often an option which is more beneficial in the long run," she said. "The brain area sending this signal, is activated not only for bladder control, but for all sorts of control. "Controlling our impulsive desires for an immediate reward, in favour of a larger reward at a later date, is a similar type of response, originating from this same neurological area. In her study, Dr Tuk asked volunteers to drink either five cups of water containing 750 millilitres or take small sips of water from five separate cups. After 40 minutes, the estimated time water is thought to reach the bladder, researchers assessed participants' self-control. They were asked to make eight choices ranging from small, and immediate, rewards to larger, but delayed, ones including choosing to receive either $16 (10) tomorrow or $30 (18) in 35 days. They concluded that people with full bladders were better at holding out for the larger rewards later. "You seem to make better decisions when you have a full bladder," said Dr Tuk, whose study came about after sitting through a long lecture. "Maybe you should drink a bottle of water before making a decision about your stock portfolio. "Or perhaps stores that count on impulse buys should keep a