A hangover can leave you with more than a sore head in the morning — it impairs the way your brain holds and processes information, according to new research.

Anyone who has woken up after a heavy night of drinking will have suspected it already, but it seems a hangover really does affect your ability to think clearly.

Psychologists studying hangovers, which they define as the symptoms left behind after alcohol levels in the blood return to zero, have found they impair the way the brain works.

The findings indicate that the impact of an excessive night of drinking can last far longer than the time it takes to become sober again.

Indeed, anyone who has woken up to be haunted by their actions and behaviour whilst inebriated will know of the misery a hangover can bring.

The new research suggests along with the dizziness, nausea and anxiety a hangover can induce, it also leaves the brain itself less able to function.

Preliminary findings, which are due to be presented at a conference at Keele University on Thursday, show that suffering from a hangover impacts your "working memory."

This governs the ability to hold information in your mind and to manipulate it, leaving sufferers less able to perform tasks such as mental arithmetic.

Dr Lauren Owen, Marie Curie postdoctoral research fellow at Keele University’s school of psychology who has been leading the research, said: "Most people are familiar with the undesirable hangover effects that may arise the day after excessive drinking.

"What’s more the symptoms of alcohol hangover are not just physiological — they affect cognitive functioning and mood as well which may lead to numerous undesirable life consequences.

"Although numerous scientific papers cover the acute effects of alcohol consumption, researchers have largely neglected the issue of alcohol hangover.

"We are measuring a large range of cognitive functions using a comprehensive battery of neuropsychological tests which will reveal the associated brain functions that may be impaired.

"The findings are preliminary, but so far we are observing that tasks that rely on what psychologists call 'working memory' seem to be most reliably affected.

"So far we have found there are statistically significant differences on these tasks compared to the 'no alcohol' condition however the magnitude will not be fully apparent until all the data is in."

She said that the early results seem to indicate a 5-10 percent drop in performance of working memory and an increase in errors by around 30 per cent while participants were hung-over.

Reaction times were also marginally slower in those who were hung-over and represented someone in their 20s having the reaction times equivalent to someone in their 40s.

The conference will also hear about new evidence from the Netherlands about how a hangover induced by alcohol can also have an affect on driving performance.

Researchers have also been examining whether alcohol induced hangovers decline in with age.

Dr Richard Stephens, a senior psychology lecturer at Keele University who has organised the conference, said: "People tend to think that hangovers get worse with age, but we are finding that people generally suffer fewer hangovers.

"This is probably because older people learn what they can drink and what they cannot.

"We have still to compare an older person with a younger person who drink the same thing."

The scientific cause of hangovers is still not well understood. While it is thought to be partly a symptom of dehydration, chemicals in the drink are also thought to play a role.

The main form of alcohol found in drinks is ethanol, which the body breaks down into chemical called acetate so it can be expelled from the body.

However, it can briefly form a toxic molecule called acetaldehyde during that process.

Low levels of methanol that can also be found in some alcoholic drinks and when this is broken down it forms more toxic compounds.

Complex organic molecules known as congeners can also be found in darker alcoholic drinks and are also thought to worsen a hangover.

It may go someway to explaining why drinking whisky can cause more of a hangover than drinking vodka.

However, for anyone reading this and suffering from a hangover, Dr Stephens says there may be some evidence to support one common cure.

He said: "The enzymes in our bodies preferentially break down ethanol over methanol.

"So if they are breaking down methanol and producing these toxins, drinking a bit more ethanol will help.

"So there is a biological basis for hair of the dog."

However, he adds, this may simply put off the inevitable and there is evidence that alcoholics suffer worse hangovers.