Classical music may only have limited effects on academic performance according to a study released Wednesday by Harvard's Graduate School of Education.

The study counters popularly-held theories that say exposure to and participation in music and drama lead to increases in test scores and grades.

The three-year study completed by Harvard Project Zero researchers Ellen Winner '69 and Lois A. Hetland, was a synthesis of various individual studies on arts education conducted over the past 50 years.

According to the researchers, their study is the largest and most comprehensive study ever conducted on the link between arts education and performance in academic disciplines.

"Nobody has ever looked carefully at the evidence," Winner said.

The study does not completely dismiss the so-called "Mozart effect"--that music can be beneficial to overall well-being--but is more reserved in describing the benefits produced by art.

The study indicated there is clear evidence that children who learn to make music have permanently-improved spatial skills--the ability to imagine objects and manipulate them mentally.

The researchers also found students' verbal skills were improved when they participated in dramatic arts in school.