The Development of Reward Processing and Risky Behaviors in the Brain

Abstract

Adolescence is a period of heightened risk taking which can lead to many negative consequences. This increased risk taking may be related to developmental changes in the reward processing system in the brain. The current study proposes to investigate individual differences in the development of the reward processing system as well as cognitive-based regulatory processes in the developing brain, and how heterogeneity in neural and autonomic activity related to these processes may predict risk-taking behavior. Despite crucial developmental changes in the reward system leading to hypersensitivity to reward, there is great variability in risk-taking and sensation seeking behaviors seen in adolescents. This dissertation reviewed current literature on adolescent risk-taking and factors that contribute across multiple levels of analysis including neural, autonomic, behavioral, and reported measures to determine whether the dual systems model put forth by Casey (2008) and Steinberg (2008) remains useful and relevant given recent developments in the literature. This dissertation also aimed to examine this variability to determine whether there are different neural signatures that may predict those adolescents who take the greatest risks and therefore who may be the most likely to suffer negative consequences from this risk-taking activity. To address this, neural activation was examined during tasks designed to examine reward processing and inhibitory control and relate this activation to risk-taking behaviors between children (7-9 years), adolescents (13-15 years) and adults. EEG measures tracking the feedback-related negativity (FRN) and N2 components allowed for the detection of the salience of actual and expected outcomes (i.e., reward sensitivity) and to examine inhibitory control ability, respectively. Additionally, this dissertation examined self-regulation in relation to risk-taking propensity by measuring Respiratory Sinus Arrhythmia (RSA) activity as it has been suggested that individual differences in self-regulation may contribute to differences in risk-taking proclivity. The results of the study will advance our knowledge about brain development during adolescence and may offer insight into the perseveration of risky behaviors despite potentially harmful and/or life-threatening consequences. The addition of investigating self-regulatory processes may help identify those who are most susceptible to the rewarding effects associated with risk-taking, and the serious/life-threatening consequences that may follow.