Further research indicated a difference between adults and children in their ability to lessen emotional responses. Mario Beauregard of the University of Montreal demonstrated the importance of age in emotional control with a two-part experiment. In the first part, he performed fMRIs on women between ages twenty and thirty, and on girls between ages eight and ten. While being brain scanned, both groups watched clips from motion pictures designed to induce sadness. Both groups’ brain activated the usual regions associated with sadness, including the ventrolateral prefrontal cortex and the anterior temporal pole.
CHILDREN RAISED in a home where two languages are spoken grow up fluent in both and don’t have an accent. Adults, on the other hand, often struggle to pick up a second language, and even when they succeed they don’t sound like native speakers.
The difference lies in the greater plasticity of the child’s brain. Young children recognize a greater range of language sounds than an adult. They pick up vocabulary and syntax more easily. And they process languages more efficiently, activating smaller regions of their brain than do adult learners, who draw on more widespread cortical regions when communicating in their nonnative tongues.
Although the brain is particularly sensitive to learning languages at a young age, it’s never too late to benefit from the mental gymnastics of wrestling with a new tongue. Adding a second language improves cognitive skills and memory, as well as exposing the learner to new ideas. Studies in Britain in 2004 revealed that those who spoke a second language had denser gray matter in their left inferior parietal cortex. Age even offers certain advantages to learning a second language: The mature learner already knows something about grammar and has a wide set of skills for learning, including literacy skills and memory aids.
In the follow-up test, Beauregard continued the fMRIs and asked both groups to suppress their feelings of sadness. This time, the scans differed. Both groups’ brain activated its prefrontal cortex and anterior cingulate, but the girls also showed activity in their hypothalamus, a region associated with intense emotion. The women had no such reactions. Beauregard’s conclusion: The women had a fully developed prefrontal cortex, allowing them greater control over their emotions. The girls lacked such development and therefore the associated self-control.
Like a brakeman on a train, a mature prefrontal cortex in a healthy adult functions as an emotional modulator. It can release to express emotions at appropriate times, such as joy at births and weddings, and conversely it can dampen emotions at inappropriate times, such as sexual arousal or rage at an office party.
“The ability to modulate emotions is at the heart of the human experience; a defect in this ability may have disastrous social and emotional consequences,” Beauregard said.