The teenage years are strongly associated with risky behaviors, thrill seeking, and instant gratification. Kids may think their daring dos make life exciting and parents may lose sleep worrying over their teens but a new study of brain activity suggests risky behaviors that promise high rewards may actually be an age-appropriate way of fast-track learning.
Lead author Juliet Davidow, a researcher at the Harvard University Affective Neuroscience and Development Lab, developed the study after questioning how negative these behaviors truly are. “In neuroscience, we tend to think that if healthy brains act in a certain way, there should be a reason for it.” She and her research colleagues set out to find a positive angle for what is so often seen as negative choices.
Davidow and her research team recruited teenagers and adults for the study that involved them to undergo functional magnetic resonance imaging (fMRI) scans while playing a computer game. The researchers were interested in seeing who two parts of the brain respond to challenges that promise reward:
· Striatum – The body produces the hormone, dopamine, in response to pleasure. Dopamine then sets off a flutter of activity in the striatum, a structure in the center of the brain involved with planning action and movement, making decisions, motivation, evaluation of consequences (reinforcement), and perception of reward.
· Hippocampus – This small structure within the brain sets below the striatum and is important for long- and short-term memory, spatial memory (one’s surroundings), navigation. The hippocampus has been described as keeping up with the who, what, when, and where aspects of life.
Between plays of the game, random unrelated images were presented to the player. The teenagers were quicker to pick up on the game than the adults were, which was the expected outcome.
Activity in the striatum was about the same for teens and adults but the hippocampus in the teens also became activated. There was little, if any, hippocampal activity in the adult brains.
Learning in Action
Memory tests came next, to see if hippocampal activity facilitated learning. It did, especially when associated with a reward.
When asked to recall the randomly projected neutral images between plays of the game, both adults and teens did well remembering them. The teens, however, were considerably better than adults at remembering the images associated with reward (getting the plays right in the game).
The research indicates the reward-seeking striatum works in conjunction with the memory-producing hippocampus to make learning quick and easy for teens. This activity could be highly valuable during the transition phase of life when a person grows away from being a dependent child into an independent adult.
And Then There’s the Hormone Issue
Another recent study found girls 11 to 13 years old are more inclined to choose risk when self-gratifying reward (social standing or money) is a possibility. Imaging of the entire brain showed the most activity in the anterior insula when the reward was of a social, rather than monetary, nature. Anterior insula activity was most active in girls with high levels of the female hormone, estradiol.
These studies may offer some degree of comfort after a study from Arizona State University found mothers consider parenting the most challenging when children are middle-school age. It seems science can confirm hormones make the adolescent brain prone to do crazy things but it seems to be for a good cause. It could help them transition more effectively into adulthood.
Sources:
Davidow, Juliet Y, Karin Foerde, Adriana Galván, and Daphna Shohamy. "An Upside to Reward Sensitivity: The Hippocampus Supports Enhanced Reinforcement Learning in Adolescence." Neuron / Cell92.1 (2016): 93-99. Web. 7 Oct. 2016.
Op de Macks, ZA, et al. "The effect of social rank feedback on risk taking and associated reward processes in adolescent girls." PubMed. Social Cognitive and Affective Neuroscience (Oxford University Press), 10 Sept. 2016. US National Library of Medicine / National Institute of Health. Web. 7 Oct. 2016
