Rewards and Risk-Taking in Adolescence

by Lauren Graf, Neuroscience major, Kenyon College Class of 2020

In this blog post I have decided to discuss motivational systems, including risks and rewards, in adolescence. This post is based off of an annotated bibliography in which I looked at articles that focused on these motivational systems. The topic is one of major interest, as everyone goes through adolescence and may experience these changes in their lives. 

Article 1:

Galván, A. (2013). Sensitivity to reward in adolescence. Current Directions in Psychological Science, 22, 100-105.

Galván begins by defining adolescence as a time period during which individuals exhibit more risk-taking behavior and have heightened reward sensitivity while also developing social, physical, and cognitive skills needed for independence. She mentions how this increased risk-taking and heightened reward sensitivity may actually be beneficial in helping adolescents learn from novel experiences in order to become more independent. She then also defines reward sensitivity as increased motivation to obtain rewards and an increased response to the rewards. It is not hormones alone that are controlling these changes in adolescents, as they work together with the developing brain. Galván states the goal of the paper is to focus on how adolescent reward sensitivity is seen across species, how changes in the dopamine neurocircuitry results in heightened reward sensitivity in adolescents, and how there are individual differences in reward sensitivity and how these may be predictive of “real-world” scenarios. Even though this increased risk-seeking behavior may produce outcomes that are not ideal, it is necessary to help individuals grow and develop.

Researchers have tested rats and other non-human primates and compared their reward-related behavior to that of humans. They found that adolescent rats also demonstrate increased reward seeking, risk taking behaviors, social interactions, and an increased interest in drugs, just as in human adolescents. These results help to support evidence that there are actual changes in the brain causing these behaviors, and that it is not just cultural or social norms. Many studies have chosen to focus on changes in the dopamine system, which fires in response to rewards, social interactions, and unexpected events and stimuli. This response then leads to approach behavior, as an individual is going to want to do something more often if there is a reward involved. In adolescence, it has been shown that dopamine D1 and D2 receptors increase in the ventral striatum, while it has also been observed that the dopamine neuron firing rates and the number of activated dopamine neurons in anticipation of reward both peak in adolescence.

https://www.everydayhealth.com/dopamine/

Studies have also helped to show that adolescents have an increased sensitivity to different types of rewards. For example, it has been shown that adolescents have the greatest ventral striatum activation in response to the largest monetary reward. They became slower at responding to the smaller rewards, and quicker to react to the larger rewards. This hyperresponsive view is also supported by other work that found that adolescents had more activity in the VS when earning money, and that there is a heightened VS response to both the preparation for a reward, and the expected and unexpected reward outcomes. This has all been found to correlate with “real-world” sensitivity and task performance.

Another important topic that Galván touches on is that there are individual differences in reward sensitivity. Those who are more likely to participate in risk-taking behavior and who seek novelty are more likely to be more reward-seeking. Work by Galván has shown that those who have greater VS recruitment are more likely to exhibit risk-taking behavior more often. It has also been shown that hormones do have an impact on the dopamine system. For example, studies have shown that adolescents who have higher levels of testosterone had an increased reward-related activation in the VS. While the developing brain is an important factor in reward sensitivity, puberty does also play a role in this.

Galván concludes the paper saying that more research needs to be done determining the importance of the prefrontal cortex in this system, how other individual factors may influence behavior and risk-taking tendencies, and how this reward sensitivity affects learning. It is important for us to determine these questions and do more research on the topic in order to be better able to help adolescents at home and in schools. 

Article 2:

Braams, B. R., Peper, J. S., van der Heide, D., Peters, S., Crone, E. A. (2016). Nucleus accumbens response to rewards and testosterone levels are related to alcohol use in adolescents and young adults. Developmental Cognitive Neuroscience, 17, 83-93.

The authors begin by describing adolescence as an important developmental time period in which individuals will exhibit increased risk taking behaviors such as experimenting with alcohol and drugs. While many of the changes that adolescents experience are adaptive and help them to become more independent, some of them may be detrimental, like excessive alcohol consumption. 32% of emergency treatments from alcohol poisoning in the Netherlands was to help adolescents 15-19 years old. This shows that excessive alcohol consumption is a major detrimental risk that many adolescents are taking. Due to this, the researchers wanted to know more about the relationship between alcohol consumption in adolescents and changes in the brain. The ventral striatum, particularly the nucleus accumbens, has been known to be associated with increased risk-taking and reward-seeking behavior in adolescence, so it was of major focus for the research group. They used fMRI information in which participants completed a gambling task from a previous longitudinal study in adolescence over two time points. Researchers also had participants fill out an alcohol consumption questionnaire that tested average alcohol consumption per evening, alcohol consumption over the past month, and total lifetime alcohol consumption. In addition, participants were also asked to provide a testosterone sample from saliva. Participants varied in age from 8 to 27 years old. The researchers hypothesized that age and alcohol use would have a positive correlation, that participants with higher reward responses in the nucleus accumbens during the gambling task would have higher alcohol use, and that higher levels of testosterone would also be seen with higher alcohol use.

https://bodytomy.com/structure-function-of-nucleus-accumbens

Results showed that there is a positive correlation between nucleus accumbens activation in response to receiving a reward and the average amount of alcohol consumed per night. The study also demonstrated that testosterone levels from the first time point could help to predict alcohol use at the second time point, however, the nucleus accumbens activation at the first time point did not predict alcohol consumption at the second time point.

To conclude, the researchers state that there is a relationship between real-world risk-taking behavior and brain activation to rewards. They also mention that based on the findings that testosterone levels can be predictive of alcohol consumption in the future, it should be looked at how testosterone levels have an impact on brain development and how these combined impact real-life risk-taking.

Article 3:

Braams, B. R., van Duijvenvoorde, A. C.K., Peper, J. S., Crone, E. A. (2015). Longitudinal Changes in Adolescent Risk-Taking: A Comprehensive Study of Neural Responses to Rewards, Pubertal Development, and Risk-Taking Behavior. The Journal of Neuroscience, 35(18), 7726-7238.

The authors begin by stating that adolescence is a time of development and risk-taking. They then mention the nucleus accumbens, and how it is a crucial area of the brain involved in the brain’s reward circuitry, specifically during adolescence. However, the relationship between the nucleus accumbens activity and risk-taking is not well understood. One factor they discuss that might help explain the relationship between the two is testosterone levels. Another factor they mention is individual differences in risk-taking behaviors. This longitudinal study was designed in order to test the relationship between nucleus accumbens activity to rewards, pubertal development, and risk-taking behavior. Participants were from the age of 8 to 27, and participated in multiple tasks. There was a gambling task which involved winning or losing money, a balloon analog risk task (BART) which corresponded with real-life risk-taking behaviors, a Behavior Inhibition System/Behavior Activation System (BIS/BAS) questionnaire for self-reported risk-taking tendencies, a Pubertal Developmental Scale, and testosterone levels were measured through saliva.

Results helped to confirm that there is a peak in nucleus accumbens activation in response to rewards, which had been identified in earlier studies. This is seen to be associated with a structural change in the volume of the nucleus accumbens. Results from this study have also concluded that pubertal changes begin earlier in girls than in boys based on self-reported information, and a serious increase in testosterone is seen in boys around age 10 as compared to a moderate increase in girls. When assessing risk-taking in individuals using the BART task, there was a peak in adolescence, which was also seen in previous studies. However, when measuring risk-taking through a self-assessment, there was no change over age which could possibly be due to individual differences aside from age. Self-reported risk-taking might just show the risk taking tendency of the individual, not how it changes over time, while using the BART to measure risk-taking shows when individuals are more likely to make risky decisions. The researchers also found that individuals with higher BAS scores over time had greater increases in nucleus accumbens activity, so the differences in self-reported risk-taking correlate with activity in the nucleus accumbens. Lastly, they found that elevated nucleus accumbens responses to rewards were related to increases in puberty and higher testosterone levels.
The authors conclude by saying that future research is needed in order to determine factors that lead to a stabilized response to rewards in adulthood. Having this information may be able to help more individuals control their risk-taking tendencies and make safer decisions.

References

Braams, B. R., Peper, J. S., van der Heide, D., Peters, S., Crone, E. A. (2016). Nucleus accumbens response to rewards and testosterone levels are related to alcohol use in adolescents and young adults. Developmental Cognitive Neuroscience, 17, 83-93.

Braams, B. R., van Duijvenvoorde, A. C.K., Peper, J. S., Crone, E. A. (2015). Longitudinal Changes in Adolescent Risk-Taking: A Comprehensive Study of Neural Responses to Rewards, Pubertal Development, and Risk-Taking Behavior. The Journal of Neuroscience, 35(18), 7726-7238.

Galván, A. (2013). Sensitivity to reward in adolescence. Current Directions in Psychological Science, 22, 100-105.

Galván’s Introduction to Adolescence: The Relationship Between the Developing Brain and Behavioral Expression

by Kaiya Case, Kenyon College, ‘22

The following post is an annotated bibliography reviewing three separate scholarly articles, all rooted in the concept of adolescent neurological development as it translates into functional behavior. Stemming from key adolescent tendencies which Adrianna Galván touches on in the first few chapters of her text The Neuroscience of Adolescence, the studies detailed examine particular manifestations of impulse control, risk-taking, and the progression towards independence.

1. Article from the “further reading” suggestions at the end of the chapter: Casey, B.J. (2015). Beyond simple models of self-control to circuit based accounts of adolescent behavior. Annual Review of Psychology, 66, 295-319. Retrieved from: https://www-annualreviews-org.libproxy.kenyon.edu/doi/10.1146/annurev-psych-010814-015156
This article (recommended at the end of chapter one) discusses many of the same adolescent tendencies and related neurological models brought up by Galván, namely that of increased impulsiveness and experimentation. Though adolescents are physically in their near ‘prime’ in many ways, Casey first notes that their diminished self-control and inhibitions lead to increased mortality (specifically a 200% increase in preventable deaths) throughout such a challenging time of multi-leveled change. There exists within the adolescent brain a seeming inconsistency between increased “sensation seeking” but also the peak of anxiety and mood disorders. Casey points out the semi-hypocrisy of the negative, ‘defective’ connotation with adolescent tendencies for acting up. The brain has a lot to accomplish in adapting to drastically and rapidly changing both internal and environmental factors.
This article outlines two major approaches to understanding adolescent neuroscience and behavior: 1. “Translation,” which works across species uncovering evolutionarily-grounded behaviors. For example, all mammals exhibit patterns for increased interest in novelty and exploration as well as peers over parents during the adolescent period. These prove adaptive functions for reproductive success as steps towards independence and self-sufficiency, allowing for improved resource acquisition. 2. “Transition,” which examines the specific development between the stages of childhood, adolescence, and adulthood.
Casey also touches on the “hot” and “cold” brain systems described briefly by Galván, where adolescent neuroscience is considered through the lens of active response to surrounding events (hot) vs. implicit mental planning and calculation (cold) in a ‘dual-system model of willpower.’ Puberty amplifies signaling in the hot system, which is likely responsible for disrupting the cold system, emphasizing immediate over delayed reward. In addition to the two system concept, there are three key interconnected brain areas mainly involved in self-control: the amygdala, prefrontal cortex, and ventral striatum. During adolescence, temperamentality increases especially in regards to social cues, which results in less caution when it comes to motivated behavior. Casey cites a number of studies dealing with such behavior, including one that showed more risky gambling choices in adolescents relative to adults, and another reporting a dulled ability to suppress responses toward an unexpected social cue. He also talks about control in regards to perceived threats. Despite the cultural association with adolescents thinking themselves invincible, the opposite has revealed itself in a number of ways such as adolescent overestimation of danger and fatality relative to adults. While adolescents can properly appreciate consequences, they are more susceptible to getting wrapped up in the heat of the moment, with social factors and increased emotional charge fueling the fire.

2. Empirical article published in the past four years: Takamura, T., Nishitani, S., Suegami, T., Doi, H., Kakeyama, M., & Shinohara, K. (2015). Developmental changes in the neural responses to own and unfamiliar mothers smiling face throughout puberty. Frontiers in Neuroscience, 9. https://doi.org/10.3389/fnins.2015.00200.
With its focus on the relationship between mother and child, I chose to examine this article due to the central definition provided by Galván in The Neuroscience of Adolescence that the adolescent period ends roughly when the individual establishes independence from parental figures. Takamura et al. reinforce the importance of early, positive mother-child connection in building social relationships with others in all different ways later in life This is especially significant as peer interaction becomes much more prevalent during adolescence, yet the parent-child bond is classically known to shift in dynamic at that same time.
The study explicated in this article compares the neural response of males at three different developmental stages throughout puberty to a video of their respective mothers’ smiling. The sample of boys was split roughly into thirds between those just pre-puberty, near the height of puberty, and those who recently exited the pubertal phase. Response was measured specifically in the anterior section of the prefrontal cortex, and weighed against the neural response induced by the sight of an unfamiliar mother’s smiling face. It was found that the right inferior and medial parts of the anterior cortex would activate in those pre-puberty, while the left inferior, medial, and superior parts would light up in the mid-puberty group. Researchers concluded that this signified feelings of empathy, developed by supportive memory traces of maternal connection. Post-puberty demonstrated a lack of active response, indicating decreased interest in and reliance on parental figures.

3. Supplementary article: Galvan, A., Hare, T., Voss, H., Glover, G., & Casey, B. (2007). Risk-taking and the adolescent brain: Who is at risk? Developmental Science, 10(2), F8-F14. Retrieved from: http://search.ebscohost.com.libproxy.kenyon.edu/login.aspx?direct=true&db=mnh&AN=17286837&site=ehost-live.

Galván also talks a great deal in her introduction to adolescence as a whole as well as the concept of puberty about the idea of risk-taking as it has been traditionally associated with the adolescent stage. This empirical article (where Galván herself is involved as one of a number of responsible researchers) begins by noting the individual differences in impulsivity despite an overall tendency towards it and assumed cultural connection. While neurological reward-anticipation has been linked to risky behavior, and specifically greater nucleus accumbens (part of the ventral striatum) activity has been demonstrated in adolescents in comparison to their child and adult counterparts, this study strived to determine (over different developmental stages) whether accumbens activity directly correlates with the likelihood to undertake risks.
Galván et al. tested this central question through the use of fMRI conducted on participants ranging from child to adult, while following a certain version of the ‘Cognitive Appraisal of Risk Activities’ to assess how each individual weighed possible risks and consequences in regards to a given situation. While adults and adolescents indicated an association between accumbens activity and both negative and positive perceived consequences of risky behavior engagement, children did not. On the other hand, children and adolescents associated anticipated negative consequences with logically less engagement in risky behavior, but the anticipated pitfalls did not significantly sway the likelihood for engagement in adults. Whether an individual will perceive the consequences of an action as negative or positive is linked to both accumbens activity and their likelihood of engaging in risky behavior, and that proved true across all developmental stages. The researchers deduced that a change in the anticipation of risky behaviors’ consequences could therefore form the basis for the adolescent tendencies towards risk-taking, with the short-term benefits (such as peer admiration and overall social status) outweighing for them the potential long-term negative consequences. Additionally, as far as individual variation goes, case-by-case differences in consequence perception could determine whether the adolescent actually chooses to engage in the behavior.

Retrieved from: https://www.jyi.org/2018-may/2018/4/26/seeking-happiness-understanding-the-mechanisms-of-mixing-music-and-drugs

Retrieved from: https://www-annualreviews-org.libproxy.kenyon.edu/doi/10.1146/annurev-psych-010814-015156

Retrieved from: https://www.sciencedirect.com/topics/neuroscience/ventromedial-prefrontal-cortex

References:

Casey, B.J. (2015). Beyond simple models of self-control to circuit based accounts of adolescent behavior. Annual Review of Psychology, 66, 295-319. Retrieved from: https://www-annualreviews-org.libproxy.kenyon.edu/doi/10.1146/annurev-psych-010814-015156.

Galvan, A., Hare, T., Voss, H., Glover, G., & Casey, B. (2007). Risk-taking and the adolescent brain: Who is at risk? Developmental Science, 10(2), F8-F14. Retrieved from: http://search.ebscohost.com.libproxy.kenyon.edu/login.aspx?direct=true&db=mnh&AN=17286837&site=ehost-live.

Galván, A. (2017). The Neuroscience of Adolescence. Cambridge: Cambridge University Press. (Chapter 1: “What is Adolescence?” & Chapter 2: “Puberty”)

Takamura, T., Nishitani, S., Suegami, T., Doi, H., Kakeyama, M., & Shinohara, K. (2015). Developmental changes in the neural responses to own and unfamiliar mothers smiling face throughout puberty. Frontiers in Neuroscience, 9. https://doi.org/10.3389/fnins.2015.00200.

Adolescent Risk Taking

by Kylie Baker-Williams, Kenyon College, 2022

This is an annotated bibliography of risk taking in adolescents. Here I will review three articles that look at why it happens, who's at risk, and how peers influence risk taking behaviors.

So, what is happening in the brain that results in this risky behavior? Qu, Y., Galván, A., Fuligni, A. J., Lieberman, M. D., & Telzer, E. H. (2015). Longitudinal changes in prefrontal cortex activation underlie declines in adolescent risk taking. Journal of Neuroscience, 35, 11308-11314.

A study by Galván, Fuligni, Lieberman, and Telzer was done in order to determine the way the prefrontal cortex functions in the context of adolescent risk-taking. The researchers took a group of 24 adolescents and gave them two fMRI scans, about a year and a half apart. At both scans, the participants reported their involvement in risk-taking activities using the Youth Self-Report. In order to examine the participants' sensitivity to risky behaviors, they completed the Balloon Analog Risk Task while undergoing the fMRIs. The final results from this study do not include two of the participants due to excessive head movement. The researchers did not find an overall change in behavior with the BART test, however, declines in risk-taking on the BART did covary with declined self-reports of risky behavior. When they looked at the neural results they found heightened activation in cognitive control and reward-related networks during the first and second scan. When they compared the two scans they found that the second scan, the one taken about 1.5 years later, showed less activation of the VLPFC in the participants compared to their first scans. They also found that the participants that reported less risk-taking behavior also had less activation in their VLPFC and VS than other participants. These findings suggest that higher activation of the VLPFC is an important part of risk-taking behavior in adolescents, and as we get older the region becomes less sensitive and active.

What else is going on? Galvan, A., Hare, T., Voss, H., Glover, G., & Casey, B. (2007). Risk-taking and the adolescent brain: Who is at risk? Developmental Science, 10.

Another study was done in 2007 in order to figure out the reasons behind risk-taking and predict who may be more likely to take risks. The study was of 12 adults, 12 adolescents, and 13 children. Each participant was given a modified version of the Cognitive Appraisal of Risk Activities and asked to give each item 3 ratings: one on how likely they were to do the activity in the next 6 months, one on the likelihood of a negative consequence, and one on the likelihood of a positive consequence. They were also given a revised version of The Connors Impulsivity Scale in order to assess how impulsive each participant was. The subjects were then put in an fMRI in order to measure nucleus accumben activity. They were given a task where 3 cues, pirates, associated with different amounts of money, would show up somewhere on the screen followed by two treasure chests. The participant was meant to choose the treasure chest they wanted, with the goal being to make as much money as possible. Each participant received a monetary reward for participating but were told that if they did well on the task they would receive extra money. The study found that accumben activity correlated with the likelihood of engaging in risk-taking behavior in adults and adolescents. An association between activity in accumbens and predicted consequences of risky behaviors as well. Those that anticipated positive consequences from risky behavior had higher activation in their nucleus accumbens, a trend seen in adults and adolescents but not children. There was less activation of the accumbens if the participant anticipated negative consequences.

How do our peers influence our behaviors? Chein, J., Albert, D., O’Brien, L., Uckert, K., & Steinberg, L. (2010). Peers increase adolescent risk taking by enhancing activity in the brain’s reward circuitry. Developmental Science, 14(2).

In 2010 a study was conducted to test the hypothesis that the presence of peers may increase risk-taking in adolescents by activating the regions of the brain that anticipate rewards. To do this they took a group of adolescentsô, young adults, and adults and gave them an fMRI while they were in a driving simulation. The simulation had the participants drive through a course with intersections, as they would approach the light would turn yellow and the subject would have to decide whether or not to brake. The participants were offered money if they could make it through the course fast enough, motivating them to take risks. However, if they were to crash they would be unable to complete the course, which would discourage them from taking risks. Each participant did the task twice, once alone and a second time while they were being watched by their peers, two friends of the same age and sex. The peers were allowed to talk with the subject while the watched and were instructed to tell the subject that they were there, able to see the subject’s performance, and had already predicted how the subject would do. The data showed that adolescents took significantly more risks, deciding to go through the yellow light, while being observed, and were the only group to do so. The fMRI showed that specifically relative to adults, adolescents had much more activation in the ventral striatum and orbitofrontal cortex, but only when they were being observed by their peers. These findings may indicate that adolescents feel the reward to be higher and more important while peers are around.

Chein, J., Albert, D., O’Brien, L., Uckert, K., & Steinberg, L. (2010). Peers increase adolescent risk taking by enhancing activity in the brain’s reward circuitry. Developmental Science, 14(2).

“Dopamine Pathways.” Okinawa Institute of Science and Technology Graduate University OIST, 12 Oct. 2015, www.oist.jp/news-center/photos/dopamine-pathways.