London, July 21 (IANS) A study has revealed that Botox can make people feel happy because it stops them frowning when they are unhappy.

The anti-wrinkle drug sends back the signal to the brain reducing the intensity of the feeling.

Scientists at University of Wisconsin in the US tested 40 volunteers who had small doses of Botox into their forehead. They were then asked to read out a series of written statements ranging from ones that were "angry" to "sad" to "happy" both before and after their treatment.

Like any kind of paralysis, blocking the body's natural movement can have an effect on emotion, said the study authors.

When those who had received the treatment read out the more negative statements they took slightly longer to do so than they had before having the injections.

According to researcher David Havas, the time delay was tiny but significant because it suggests the brain takes longer to process the emotion behind the statements.

"There is a long-standing idea in psychology called the facial feedback hypothesis Essentially, it says, when you're smiling, the whole world smiles with you. It's an old song, but it's right," telegraph.co.uk quoted Havas as saying.

"Actually, this study suggests the opposite: When you're not frowning, the world seems less angry and less sad."

Research leader professor Arthur Glenberg added: "Normally, the brain would be sending signals to the periphery to frown, and the extent of the frown would be sent back to the brain.

"But here, that loop is disrupted, and the intensity of the emotion and of our ability to understand it when embodied in language is disrupted.

However, having Botox in the lower part of your face can prevent a smile and have the opposite effect, a research last month from Barnard College, New York, suggested.