Alumna discusses research focused on brain’s frontal lobes


On Thursday, January 12, Marisa M. Silveri, PhD, a graduate of Union College, class of 1995, gave a lecture on the developing mind of adolescents. Dr. Silveri is a neuroscientist and director of the Neurodevelopment Laboratory on Addictions and Mental Health at McLean Hospital and an Associate Professor of Psychiatry at Harvard Medical School.

During Dr. Silveri’s time at Union College, she looked up to Professor Carol Weisse, Director of Health Professions and Professor of Psychology. Her courses inspired Dr. Silveri’s research on the ‘rollercoaster ride that is the adolescent mind.’ Dr. Silveri’s research focuses on the neurobiology of the developing brain and the consequences of alcohol and drug abuse on the efficiency of frontal lobe activity.

Starting around 12 years old until about 21, the brain undergoes construction to improve cognitive performance; as Dr. Silveri puts it, “this is how we get better cell service.” This remodeling period, most influential in the frontal lobe, is the most rapid rate of change for the brain after it reaches its full size around age five.

The remodeling, is so quick that there are “significant, visible changes in brain functioning even from the fall term of freshman year to the spring term,” Silveri explains. Before the frontal lobe is fully developed, the amygdala is mainly responsible for our emotions and thought processes, influencing how we react to situations based on impulses and desire for instant gratification. The frontal lobe’s job is to inhibit the amygdala’s response with more complex, moral thinking.

Before the ability to restrain from temptation develops, “parents need to be their children’s frontal lobe.” Teens have a less efficient ability to restrain from enticing opportunities. As a Union College alum, Silveri explained her findings in a situational example applicable to many college students: “Should I stay in or should I go out?”

The quick, impulsive response is go out and have fun with friends, the option many teens find hard to ignore. The thought out response, stay in and study, is less easily reached, even though it has far fewer consequences.

As the brain enhances its decision making potential, the internal conflicts between the amygdala and frontal lobe increase. The common belief that only 10% of the brain is working at one time is a myth. All of the brain is working simultaneously and thus the brain often conflicts itself when an “either-or situation” arises.

To further support her point, Dr. Silveri had the audience participate in a Stroop test. The Stroop test, a classic indication of frontal lobe functioning forces the brain to mediate the prefrontal cortex actions. The task is to name the color a word is written in, instead of reading the color the word says. The more developed the frontal lobe is, the easier it is to inhibit the automatic response, reading, with the less automatic response, naming the color.

Replicable findings of the Stroop test show that teens perform quickly but inaccurately, whereas adults perform more slowly but accurately. College age individuals should perform at the optimal interaction of efficiency and accuracy, however performance is notably hindered by the impact of drugs and alcohol on the brain.

During the “neurocircuitry pruning process,” the brain is left more vulnerable to drug abuse, addiction and psychiatric illnesses, often occurring the same time use of alcohol and drugs increases for many young adults. The effects of alcohol are well known, excessive binge drinking impairs learning and memory, both functions of the developing frontal lobe, however the long term effects of excessive marijuana use are less well know.
Silveri’s studies show that abuse of marijuana disrupts frontal lobe development by decreasing the interactivity of sections of the frontal cortex on performing tasks such as the Stroop test, as much as a 10% decrement in efficiency. Dr. Silveri’s main interest in this field of study is to educate young adults on the effects of exposing our brains to drugs and alcohol before we have reached what she likes to call “neurobiological adulthood.”


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