How Genes Influence Human Behavior and Cognitive Abilities

Our genes partially define who we are and how we act. Yet studying how genes influence cognitive abilities and behavior as the brain develops from childhood to adulthood has been difficult thus far. Now, scientists have managed to make inroads when it comes to understanding how genes influence brain structure and cognitive abilities and how neural circuits produce language.

In order to learn a little more about how genes impact the brain and human behavior, the researchers studied patients with a rare disorder known as Williams syndrome. This syndrome is caused by the deletion of one of the two usual copies of the approximately 25 genes from chromosome 7, resulting in mental impairment. It affects approximately 1 in 10,000 people around in the world, including about 20,000 to 30,000 people in the United States.

By measuring neural activity in the brain associated with the distinct language skills and facial recognition abilities that are typical of the syndrome, the scientists showed that Williams is not due to a single gene. Instead, it's due to distinct subsets of genes; this hints that the syndrome is more complex than originally thought.

"Solutions to understanding the connections between genes, neural circuits and behavior are now emerging from a unique union of genetics and neuroscience," said Julie Korenberg, one of the researchers, in a news release.

These findings in particular are important. The brains of people with Williams are structured differently than those of people without the syndrome; in the Williams brain, the dorsal areas, which help control vision and spatial understanding, are undersized. The ventral areas, which influence language, facial recognition, emotion and social drive, are relatively normal in size. This reveals a little bit more about the syndrome itself.

Yet the study also provides hope for future studies. By directly measuring brain activity, scientists have the unprecedented opportunity to study the genetic underpinnings of mental disorders. The results of this particular study not only advance science's understanding of the links between genes, the brain and behavior, but also may lead to new insight into disorders like autism, Down syndrome and schizophrenia.

"By greatly narrowing the specific genes involved in social disorders, our findings will help uncover targets for treatment and provide measures by which these and other treatments are successful in alleviating the desperation of autism, anxiety and other disorders," said Korenberg in a news release.

The findings are published in the journal Developmental Neuropsychology.