Language. It is strange that a series of sounds strung together can have such meaning prescribed to it, but still language is an unparalleled tool for communication which is so intrinsic to human society, and so unique to it. According to the Global Language Monitor, there are 1,025,109.8 words in the English language, which can be combined in infinite ways to express anything. New words appear and disappear daily as whole languages do themselves over the years, evolving to match its only users–humankind.

With some notable exceptions, animals can only express things in a limited, primitive capacity, and they are born with their modes of communication pre-programmed. So what is it in the brain that allows human infants to acquire a language, to identify and commit to memory words from streams of unfamiliar sound, usually all before the age of 5? Well, no one can say for sure.

Language processing in early infancy happens in many parts of the brain. Over the years it focuses into Wernicke’s area, located in the left temporal cortex and  is involved in language comprehension, and Broca’s area, found in the left frontal cortex and involved in detecting patterns in language. Then, all of that information is committed to long-term memory when the dendrites in the brain are activated.

While the specifics of how the brain learns a language remain shrouded in mystery, the  positive effect of learning a language has on the brain is undeniable.

A study by Lund University in Sweden examining MRI scans before and after learning a language for three months found that the brain actually grew. Specifically, three areas in the cerebral cortex and the hippocampus, which is involved in spatial navigation and learning. The amount that the study participants had learned as well as how hard they worked factored into the degree of brain growth.

“Even if we cannot compare three months of intensive language study with a lifetime… there is a lot to suggest that learning languages is a good way to keep the brain in shape,” lead researcher Johan Mårtensson said.

Other studies show that Mårtensson is on to something. People who know more than one language need to use the executive control system of their brain constantly in order to monitor which language they are speaking in, which actually gives them an edge in terms of brain health. Alzheimer’s disease and dementia are generally diagnosed four years later and symptoms begin five years later in multilingual people.

Learning a language also benefits other aspects of academics. According to data from the College Board Admissions Testing Program, monolingual students receive a mean SAT score of 366 verbal and 409 math, while students who had spent at least five years studying a foreign language receive much higher scores, a mean 504 verbal and 535 math.

A big part of what makes language so fascinating is how little is known about it, but its many known health and academic benefits are definitely worth taking into consideration next time you’re filling out course requests. Keep exercising those dendrites.