Neuroscientists from Georgetown University Medical Center say that boys and girls use different parts of their brains to process some basic aspects of grammar. Their study, published in the journal Developmental Science, suggests that gender is an important factor in the acquisition and use of language.
It appears that girls mainly use a system that is based around memorizing words and associations between them, whereas boys rely primarily on a system that governs the rules of language. "Sex has been virtually ignored in studies of the learning, representation, processing and neural bases of language. This study shows that differences between males and females may be an important factor in these cognitive processes," said the study's lead author, Michael Ullman.
In the study, the researchers examined brain activity around phrases like "Yesterday, I holded the bunny." They hypothesized that girls would be better than boys at remembering irregular past-tenses of verbs, like "held", since these words are memorized in declarative memory. And if girls remember "held" better than boys, they should make fewer errors like "holded", since these over-regularization errors are made when children can't remember irregular past-tenses, and so resort to combing the verb with an "ed" ending, just as they do for regular verbs like "walked".
The experiment took in a group of 10 boys and 15 girls, age 2 to 5, who used regular and irregular past-tense forms in their normal speech. To the researchers' surprise, and contrary to their predictions, they discovered that the girls over-regularized far more than boys.
Investigating which verbs the girls made the mistakes on, they found an association between the number of similar sounding regular past-tense verbs, and the particular verb that was over-regularized. For example, girls tended to say "holded" or "blowed" because many other rhyming verbs use the regular past-tense form (such as folded, molded, and flowed, rowed, stowed, respectively).
The researchers contend that this kind of analogy-based processing suggests the girls were relying on their declarative memory to create the past tense. "This memory is not just a rote list of words, but underlies common patterns between words, and can be used to generalize these patterns," Ullman said. "In this case, the girls had memorized the regular past tenses of rhyming words, and were generalizing these patterns to new words, resulting in over-regularization errors" such as "holded" and "blowed".
In contrast, for the boys, there was no association between the number of similar sounding regular past-tense verbs, and the particular verbs that were over-regularized. So the boys did not make more over-regularizations on verbs like "holded" or "blowed" that have many rhyming regular past-tenses. This suggests, according to Ullman, that the boys were not forming these words in declarative memory, but were probably using the rule-governed system to combine verbs with "ed" endings.
"Although the two sexes seem to be doing the same thing, and doing it equally well, they are using two different neurocognitive brain processes to do it," Ullman said. He also noted that the brain areas tested in the study are responsible for more than just language use, reinforcing the notion that men and women may process information in fundamentally differently ways.
Source: Georgetown University Medical Center
