In a fascinating study by the University of Santiago de Compostela in Spain, researchers are uncovering the means by which our brains protect against cognitive impairment. The answer seems to lie in what is called “cognitive reserve”.
“Cognitive reserve” is simply put, your brain’s extra capacity — which is something that we develop over a lifetime of learning, working and using our minds. Measuring cognitive reserve is not yet possible directly, but we can estimate the size of a person’s cognitive reserve by measuring other abilities which are reflective of the mind’s capacity.
One such ability is apparently the size of a person’s vocabulary.
The study’s co-author, Cristina Lojo Seoane describes this remarkable correlation:
“We focused on level of vocabulary as it is considered an indicator of crystallized intelligence [previously acquired abilities – Ed.]. We aimed to deepen our understanding of its relation to cognitive reserve. With a regression analysis we calculated the probability of impairment to the vocabulary levels of the participants. … This led us to the conclusion that a higher level of vocabulary, as a measure of cognitive reserve, can protect against cognitive impairment”
In the study, 326 over-50 subjects were chosen. Of these 326 subjects, 222 were healthy. 104 of the subjects showed minor signs of cognitive decline or impairment.
The researchers at the University of Santiago de Compostela then measured the vocabulary skills of each of the subjects, and asked additional questions about their reading habits and the intellectual demands of the subjects’ careers.
The results showed a clear correlation between the size of a subject’s vocabulary and his or her probability of cognitive impairment.