WASHINGTON, August 22, 2008 (AFP) - Undecided voters, including those who will decide the US presidential election in November, may have unconsciously already made up their mind, according to a study appearing Friday in the journal Science.

Using a method called 'the implicit association test,' a team of researchers lead by Bertram Gawronski from University of Western Ontario in Canada uncovered the automatic mental associations of a group of Italians who said they were undecided about a controversial political issue.

The associations revealed in the test ultimately predicted their decisions, the researchers said.

The researchers interviewed 129 residents of Vicenza, Italy -- where study co-authors Silvia Galdi and Luciano Arcuri live -- about the controversial enlargement of a US military base in their community.

'The researchers interviewed each subject twice, one week apart. Each time the participants were first asked if they were 'pro,' 'con' or 'undecided' about the expansion,' Science said in a statement announcing the article.

'They then were asked to answer questions about their beliefs on environmental, political, economic and other consequences of the enlargement of the base.'

After that they were given a test of automatic mental associations, 'in which they were asked to categorize pictures of the base, and positive and negative words, as quickly as possible.'

The whole procedure was repeated two weeks later, and the researchers found that the automatic associations made in the first round of tests 'significantly predicted their conscious beliefs and preferences as expressed in the second round.'

This kind of testing 'has many applications, but certainly political polling at election time would be one,' said Gawronski.

'It can't give answers to all questions, but it could certainly help pollsters to get more information than people now share,' he said.