41 eight- to eleven-year-olds who had studied either piano or a string instrument for a minimum of three years were compared to 18 children who had no instrumental training. Children in both groups spent 30-40 minutes per week in general music classes at school, but those in the instrumental group also received private lessons learning an instrument (averaging 45 minutes per week) and spent additional time practicing at home.
While it is no surprise that the young musicians scored significantly higher than those in the control group on two skills closely related to their music training (auditory discrimination and finger dexterity), the more surprising result was that they also scored higher in two skills that appear unrelated to music—verbal ability (as measured by a vocabulary IQ test) and visual pattern completion (as measured by the Raven's Progressive Matrices). The longer and more intensely the child had studied his or her instrument, the better he or she scored on these tests.
Studying an instrument thus seems to bring benefits in areas beyond those that are specifically targeted by music instruction, but that is not the end of the story. Although this research sheds light on the question of whether connections between music and other, unrelated skills do exist, more studies examining the causal relationships between instrumental music training, practice intensity, and cognitive enhancements are needed.
Citation: Forgeard M, Winner E, Norton A, Schlaug G (2008) Practicing a Musical Instrument in Childhood is Associated with Enhanced Verbal Ability and Nonverbal Reasoning. PLoS ONE 3(10): e3566. doi:10.1371/journal.pone.0003566