If the vocabulary abilities were made to be more comparable, however, many of the differences would disappear, indicating that vocabulary size may be a factor that moderated a person's performance in verbal fluency and naming tasks. The same study also found that bilinguals, in a version of the letter fluency task that placed more demand on executive control, performed better than monolinguals. Thus, once vocabulary abilities were controlled, bilinguals performed better on letter fluency possibilities by the enhanced frontal executive processes in the brain.