The study participants saw a set of dots (IMAGE) University of Bonn Caption on the screen in front of them for half a second. After a short pause they had to indicate whether the number had been even or odd. If the number of dots was less than five, they usually gave the correct answer without hesitation. Above that, both response time and error rate steadily increased. Credit Figure: AG Mormann/University of Bonn Usage Restrictions This image may be used together with the press release. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.