A Second Language Maintains Brain Stamina
Cognitive reserve is a woolly concept -- scientists can't yet say exactly how it works -- but it refers to resilience in losing brain capacity. This ability to resist chemical and toxic insults and maintain stamina and function prevents cognitive decline and delays neurodegeneration. Cognitive neuroscientist Ellen Bialystock from York University in Toronto has been studying bilingualism for more than two decades. In a study published in Neurology in 2010, Professor Bialystock and her colleagues collected data from 102 Alzheimer's patients who could speak two languages, and 101 who spoke only one language. The researchers found that the bilingual patients first showed symptoms of cognitive impairment a bit more than five years later than the monolinguals. And the bilingual patients were diagnosed with Alzheimer's disease nearly 4½ years later. This study confirmed findings from the same research group in a previous study. That one, conducted three years earlier, showed that symptoms of dementia appeared four years later in the 94 bilinguals compared to the 90 who spoke a single language. The researchers believe bilingualism, because it places great demands on a person’s mind, builds up cognitive reserve and can therefore postpone dementia symptoms. They wrote, "The finding of a 4 to 5 year delay in the onset of symptoms of AD is dramatic. There are currently no pharmacologic interventions that have shown comparable effects." In other words, speaking two languages is more powerful than a drug when it comes to "treating" dementia.Bilinguals Have More Efficient Brains
Brian Gold and colleagues from the University of Kentucky carried out brain imaging studies on two distinct groups of people who spoke one or more languages as they switched between simple mental tasks involving colors and shapes. What made them distinct is that one group averaged 32 years in age, the other 64 years. Being monolingual or bilingual made no difference among the young participants, but among the older people, the bilinguals were measurably faster compared to those who spoke one language. They were also better able to switch between tasks, performing as quickly and activating neural networks at a level comparable to the younger group. The researchers also found the bilingual group used less oxygen and energy because their brains were more efficient at mental tasks. That’s a particularly interesting finding. Dr. Gold concluded, "The constant use of two languages during lifetime seems to have protective effects on frontal parts of the brain that are especially susceptible to decline as we age."Better Short and Long Term Memories
In a new study published in February, researchers from Italy recruited 40 volunteers who spoke only Italian and 45 German-Italian speakers. All had been diagnosed with Alzheimer's within the last three years, yet the bilingual patients were on average five years older than the Italian-only speakers, a result that was in line with previous studies. In tests, the researchers found bilinguals had much better short and long term verbal memories, and brain scans showed they had stronger connections in frontal regions, giving them better thinking ability. The constant use of more than one language is believed to make the brain work harder and cause structural changes to create a cognitive reserve. The reserve – like any reserve, like money in the bank saved for a rainy day -- gives the brain more resistance and sets it up for better "neural compensation" to cope with degeneration when it sets in. According to lead researcher Dr. Daniela Perani, "Our finding suggests that in bilingual patients with Alzheimer's dementia, both mechanisms are at play, since neuronal loss is accompanied by compensatory increase in connectivity, allowing bilingual patients to maintain high neuropsychological performance and cognitive functioning longer than monolingual patients." As Professor Bialystock points out, while there may be many ways of keeping the mind limber, bilingualism is in a different category because "you use language every minute." One question I would have is whether acquiring a second language late in life builds up your cognitive reserve as effectively as speaking two languages from childhood on. These studies don’t address that question. But it is known that, even among seniors like myself, mental challenges such as learning a language or how to play a musical instrument delay the day when memory loss becomes a dangerous problem. And if you were brought up with or learned a second language and have allowed it to lapse, now is the time to brush up and start using it again. The research suggests it could benefit your brain immensely.