Psychologist Sandra Trehub has found that babies naturally detect changed in pitch, tempo, and melodic contours. She has also found that when the babies are played perfect fourths and perfect fifths,they smile, but express displeasure when played tritones. This had led Trehub to conclude that this is a biologically-based preference and "may explain the inclusion of perfect fifths and fourths in music across cultures and across centuries."
Evidence from PET scans and MRIs suggest the human brain is wired for music. It also seems music can enhance particular modalities of intelligence. Various experiments have shown higher test scores in math achieved by students in control groups who were given music lessons. This enhancement has been displayed only in math – other forms of intelligence were not enhanced.
The average person can remember and recognize large amounts of musical tunes, which is not usually true for memorizing and recognizing prose. This suggests the brain places preference over musical memory. When neurosurgeons stimulate the temporal lobes, patients have been known to hear music. Music can also trigger epileptic seizures which often begin in the temporal lobes. This is further explained by the following experiment:
"The brain's left and right hemispheres are connected by a big trunk line called the corpus callosum. When they compared the corpus callosum in 30 nonmusicians with the corpus callosum in 30 professional string and piano players, researchers. . . found striking differences. The front part of this thick cable of neurons is larger in musicians, especially if they began their training before the age of 7. The front of the corpus callosum connects the two sides of the prefrontal cortex. . . and the two sides of the premotor cortex…These connections are critical for coordinating fast, bi-manual movements such as those a pianist's hands execute in an allegro movement. The neural highway connecting the right and left brain may explain something else, too. The right brain is linked to emotion, the left to cognition. The greatest musicians, of course, are not only masters of technique but also adept at infusing their playing with emotion. Perhaps this is why."
Another experiment conducted comparison studies where non-musicians were taught a simple five-finger piano exercise which they practiced in the lab for 5 days, 2 hours per day. Another group mentally rehearsed this pattern for the same amount of time. In both these groups, the cortical map was changed, demonstrating the important of both mental and physical practice.
While some of the conclusions mentioned in this article have already been much discussed in the fields of music and science, it is encouraging to see that studies continue to be performed to uncover as much as is possible about the biological and neurological conditions for music in humans. The most striking experiment noted in this article is the one describing the importance of mental preparation. By merely rehearsing a musical pattern in one’s mind, non-musicians (who likely do not have much experience with such practice) were able to effect an equal mental change in their cortical maps, as did those who rehearsed physically on the piano. This emphasizes the importance of mental preparation for any musician. It is not enough to simply play a piece frequently – one must also have a thorough mental picture of the piece to ensure fluidity and precision during performances.