integer

This means that systematic variations of the compound's chemical formula, which can be represented using integer variables, result in systematic changes in its properties.

In thin layers and at large enough magnetic fields, this resistance begins to develop discreet steps with values of exactly h/ne2, where h is the Planck's constant, e is the elementary charge, and n is an integer number.

"Our study provides the clearest evidence yet for some degree of universality in music perception and cognition, in the sense that every single group of participants that was tested exhibits biases for integer ratios. It also provides a glimpse of the variation that can occur across cultures, which can be quite substantial," says Nori Jacoby, the study's lead author and a former MIT postdoc, who is now a research group leader at the Max Planck Institute for Empirical Aesthetics in Frankfurt, Germany.

The brain's bias toward simple integer ratios may have evolved as a natural error-correction system that makes it easier to maintain a consistent body of music, which human societies often use to transmit information.

When the researchers first did this experiment, with American college students as the test subjects, they found that people tended to produce time intervals that are related by simple integer ratios.