# Random Samples

Science  14 Jul 2006:
Vol. 313, Issue 5784, pp. 153

3. # THE LOWDOWN ON LOW SOUNDS

No other musical instrument fascinates scientists quite like the violin. Now, physicist Alfred Hanssen of the University of Tromsø, Norway, has set out to determine how renowned soloist Mari Kimura is able to tickle tones far lower than a violin is designed to make.

When a violinist bows a string, it vibrates most energetically at a frequency determined by its mass, tension, and length. The musician can raise the frequency by holding the string to the fingerboard. The string also vibrates at multiples of this frequency. The mix of such “harmonics” gives the instrument its character. Kimura, by bowing a string in the right place at the right speed and pressure, has figured out how to produce and control tones with frequencies lower than the deepest pitch ordinarily attainable, which is G below middle C.

Other physicists have analyzed Kimura's technique, which she debuted in 1994. They found that, by feel, Kimura controls the frequency at which the bow hairs tug and release the string, accentuating the subharmonic frequencies and minimizing others. But previous theories cannot explain, for example, how she “slides” a note continuously down in pitch to an octave below low G, says Hanssen, who recently took detailed measurements of the sounds Kimura makes and the way her instrument vibrates. “There's a fundamental piece of physics missing, and we're on the track of it,” he says. Kimura, who is also a composer, says she hopes a little more science can help her expand her art even further: “If scientists have a neat explanation for it, I may find something else I can do.”

4. # REWIRING THE BRAIN

In June 2003, 39-year-old Arkansas resident Terry Wallis suddenly woke up and started talking after 19 years in a minimally conscious state.

Wallis's astonishing recovery, after a car accident that severely damaged his brain, attracted the attention of Nicholas Schiff, a neurologist at Weill Medical College of Cornell University. Schiff examined Wallis about 8 months after he began speaking, using a technique called diffusion tensor imaging. The imager, which provides information about the brain's white matter—the “wiring” supplied by axons—revealed unusually thick cables of axons linking the left and right sides at the back of the brain, areas some believe to be involved in consciousness. Other brain scans showed the cortical regions that they connected to be more active than normal, Schiff and colleagues report in the July issue of the Journal of Clinical Investigation.

A second examination 18 months later revealed new connections and unusually strong neural activity in Wallis's cerebellum, a region important for movement and coordination. These functions also improved substantially over that period, Schiff says. The findings suggest that while Wallis was unconscious, the brain regions that survived the accident forged new connections to compensate for those that were damaged, a process that continued after he regained consciousness.

Doctors don't know whether improvement will continue. But Steven Laureys, a neurologist at the Université de Liège in Belgium, says the case adds to other recent evidence that the adult brain may have more capacity to reorganize after injury than many researchers have assumed.