Dear Science

Nicole Le, Columnist

Dear Science,

I just ate an ice cream sandwich from Dascomb in one bite. What is causing this terrible brain freeze?

Researchers refer to this as nerve pain of the sphenopalatine ganglioneuralgia — by the time you’ve gotten that mouthful out, your brain freeze will probably have passed. Regard- less of the generally harmless and temporary nature of these headaches, many of us (about a third of the population, in fact) have grown up eating popsicles and drinking milkshakes without ever having understood the looming risk of brain freeze.

Many scientists turn to brain freeze as a great and convenient way to study headaches because the two are believed to work in fairly similar ways, but especially because a brain freeze is inducible (and thus can be somewhat controlled in a laboratory setting). There are two suggested brain freeze mechanisms. In both cases, the rapid constriction and dilation of blood vessels is behind the painful sensations of headache.

In the first proposed mechanism, when cold food touches the roof of your mouth, the temperature of those blood vessels drops rapidly, causing them to shrink quickly. When the blood vessels warm up again, they expand just as quickly. This dilation is sensed by pain receptors which send pain signals to the brain via the trigeminal nerve, a nerve responsible for facial sensations.

The idea is that even though the source of all this is your upper palate, because of the way things are inherently wired up, you feel pain up near your forehead instead of your mouth. This is an example of “referred pain,” where we perceive pain in a part of the body that is distant from the part of the body that’s actually experiencing a painful stimulus.

The second explanation of all this is the body’s thermoregulatory mechanisms. These involve pumping blood to areas that become suddenly cold, and in the case of brain freezes, your skull purportedly feels an immense increase in pressure as blood is quickly redirected towards your mouth to warm it back up after a big scoop of Cowhaus. The brain freeze goes away once the arteries carrying that blood shrink back to their normal size.

Dear Science,

Why do some people have way better rhythm than others? Is great dancing at the ’Sco just a natural talent? Or do you have to learn to be a good dancer?

When scientists go to study questions like this, they have to simplify the question into something that can be tested experimentally in a convincing and efficient way, so un- fortunately, you won’t come across many scientific studies where subjects are doing the Dougie or whipping out a Charleston. Most science dealing with “motor function” in humans can’t be generalized to something as complex as dancing, and instead use  tests like how quickly and easily people can learn a tapping sequence with their fingers. A really important little chemical messenger in our brains is implicated in the variability of this skill amongst the human population. It’s a neurotransmitter called GABA that acts as an inhibitor of the constant nerve firings in our brain. Without GABA, our nerves would be firing off signals all the time, and we’d be seizing and our muscles would go through hypertrophy. However, scientists have found that people with reduced levels of GABA in their brains learn and perform motor skills better.

That’s not to say, however, that scientists haven’t tried to study dance or rhythm before. A study from 2011 revealed the first documented case of “beat-deafness,” a condition that may be related to the more widely known tone-deafness. The group believes that this rare inability to feel rhythm or move to it is caused by disconnects in the widespread brain networks involved in hearing music — specifically the auditory cortex and the inferior frontal cortex.

Considering that babies have been proven to have the inherent ability to recognize the beat in music, scientists are pretty sure rhythm and dancing originate first and foremost in our genes. In this particular study, scientists actually had subjects attempt to bounce in time to different types of music while wearing little monitors on their hips that would measure the timing of their bounces in relation to the music. One subject, referred to as Mathieu, failed  pretty miserably, and thus we have our first published case of beat-deafness!

Though in Mathieu’s case, the inability to dance on beat is irreversible (at this point), scientists say that when it comes to motor control, even if you have a biological propensity for higher GABA levels, practice actually does make, well, not perfect, but better, definitely better.