Brain Development, Impulsivity, Risky Decision Making, and Cognitive Control: Integrating Cognitive and Socioemotional Processes During Adolescence—An Introduction to the Special Issue

The duality of limited cognitive and affective processes in adolescence

Adolescence is a colorful and versatile period, accompanied by many contradictions and conflicts. Adolescents often desire to be different and unique in their thoughts, behaviors, outward appearances, and the way they are perceived by both peers and adults. However, in practice, they are generally seen as a homogenous group of individuals that share similar characteristics, such as using their own idioms and expressions, following the same fashion rules, and participating in similar activities. Indeed, it appears that one of the main motives underlying adolescent behavior is the wish to gain acceptance and confirmation from peers and significant others, often as a means of gaining self-acceptance. In accordance with socioemotional and cognitive developmental processes, this wish for acceptance and uniform identity can make adolescents socially sensitive and, in some cases, socially dependent (APA, 2002; Scott & Steinberg, 2008; Steinberg, 2008).

As a transitional period between childhood and adulthood, adolescence involves massive developmental changes in the physical, neurobiological, psychological, and social domains (Dahl, 2004; Spear, 2000). These changes affect the way adolescents perceive themselves and others, influencing the way they feel, think, and behave. Adolescence is therefore a dynamic period that embodies great potential for growth and development in various aspects of life (APA, 2002). Compared to children and adults, adolescents tend to be good at recognizing social and emotional information, seeking out new experiences, meeting new people, and confronting various challenges. Strengthened cognitive abilities during adolescence accelerates the acquisition of knowledge and learning of cognitive and emotional skills (Adams, 2005).

However, as a part of normative development, adolescents are also characterized by sensitivity to reward, emotionality, risk-taking, and impulsivity, with a tendency to act in the spur of the moment and to make rash choices regardless of the consequences (Scott & Steinberg, 2008). Rational choices and goal-directed behavior require control over impulses and emotions, as well as other executive functions such as initiating and carrying out a specific sequence of steps to reach long-term goals. While the development of these capacities is still in progress, adolescents are less capable of regulating and controlling their behavior, particularly in emotional and social contexts. They are more responsive to and more easily influence by their peers, and thus more likely to change their decisions and alter their behavior in response to social pressure (Chein, Albert, O’Brien, Uckert, & Steinberg, 2011; Somerville, 2013). This can result in a greater likelihood of engagement in risky behaviors, alone and/or in groups, in an attempt to elevate social status.

A great deal of research shows that poor cognitive control and the tendency toward impulsive behavior influence the ability to make reasonable choices in daily-life situations during adolescence. In fact, many risky behaviors that are closely related to impulsivity in adolescence, such as conduct disorders and drug abuse, remain limited to adolescence, with few developing into persistent criminals or exhibiting other maladaptive behaviors (Moffitt et al., 2011). Progressive cognitive changes that strengthen the ability to learn and to act rationally, alongside increasing rates of reckless and risky behavior, reflect the duality of the adolescent period. This duality provides a framework for important research on the neuropsychological underpinnings of adolescent development.

Examining adolescent vulnerability (opportunity) through a developmental neuropsychology lens

With significant changes occurring in the brain every day, adolescence is an opportunity to exercise the mind by continually learning, generating new ideas, thinking creatively, and developing a notion of self. The promise and potential inherent in the profound cognitive and emotional changes of adolescence is captured in the quote below, a response to the Psalm, “Like arrows in the hands of a warrior, so are the children of one’s youth” (Psalm 127:4): “An arrow—tension sets its path. The further the arrow is stretched in the string of its bow, the greater the distance it will travel. The days of adolescence are days of stretching. Do not waste them…” (Menachem Mendel Morgensztern, the Kotzker Rebbe, 1787–1859)

During adolescence, the brain is more plastic than it will ever be again. It is thus capable of remarkable adaptability, in light of the many social, physical, sexual, and intellectual challenges that accompany this developmental phase (Casey, 2015; Dahl, 2004). However, this plasticity also has a downside: vulnerability. During this period, the prefrontal cortex (PFC), which is associated with cognitive control and significantly engaged in the integration between cognitive and affective components of behavior, is among the last neural regions to fully mature. Meanwhile, subcortical regions associated with motivational and affective processes (e.g., amygdala, ventral striatum) mature relatively early. These differences between the developmental trajectories of the PFC and subcortical structures, alongside the continuing development of self-control and other high-order cognitive functions (Dahl, 2004), contribute to adolescent vulnerability to impulsive and risky behaviors. More specifically, the gap between the early maturation of socioemotional networks and the relatively late maturation of cognitive networks creates an imbalanced state in which emotions are likely to override cognitive control mechanisms (Casey, Jones, & Somerville, 2011; Ernst, Pine, & Hardin, 2006; Steinberg, 2008). This makes it difficult for adolescents to impose constraints on stimulus-driven behaviors, and reduces their capacity for reasoning, judgment, and impulse control (Chambers, Taylor, & Potenza, 2003; Scott & Steinberg, 2008; Spear, 2000).

Maturational changes in grey and white matter, contributing to the reorganization of functional networks, also have an important influence on the adolescent brain. Within this context, the two processes of pruning and myelination play a particularly important role in the interaction between emotional and cognitive processes and their effect on adolescent behavior (Spear, 2000). Pruning is a neural process by which unused information is eliminated. It occurs during childhood, adolescence, and adulthood, but is most extensive during adolescence. Approximately 1–2% of the brain is pruned each year during childhood and adulthood, whereas during adolescence, this rises to 15% (Beckman, 2004; Brenhouse & Andersen, 2011). Contrary to pruning, myelination increases the speed at which information travels between nerve cells, allowing for more efficient and faster communication and resulting in a higher quality of thinking (Brenhouse & Andersen, 2011; Paus, 2005). It is believed to be among the processes underlying the transition from concrete to abstract thought (Chambers et al., 2003). In light of these biological changes, adolescents become more cause-oriented than younger children and their ability to solve complex problems tends to be enhanced (Luna, Garver, Urban, Lazar, & Sweeney, 2004; Spear, 2000). Still, the frontal lobes, which play a significant role in abstract thinking, reasoning, regulating emotions, and problem solving are among the last parts of the brain to undergo myelination (Rubia et al., 2006).

Thus, on one hand, adolescents acquire adult-like cognitive and emotional styles that are distinct from those observed in childhood. On the other hand, they are more reactive to emotional stimuli, show susceptibility to immediate rewards, and lack orientation toward the future, which in turn reduces their fear of punishment and their impulse control, rational decision making, and reasoning capabilities (Casey et al., 2011; Scott & Steinberg, 2008).

Integrating cognitive, socioemotional, and behavioral processes in adolescence

The current issue includes in-depth discussions of neurodevelopmental trajectories in light of neuropsychological and social models of cognitive processes related to impulsive and risky decision making during adolescence. Contributors were invited to address the question of why adolescents engage in impulsive and risky behaviors. The articles provide insight into adolescence as a unique developmental period encompassing cognitive, emotional, and social maturation. The articles vary in the populations examined and the methods employed, and are organized into three main categories: (a) imaging studies, (b) behavioral studies, and (c) a theoretical discussion.

Imaging studies

The work of Jollans and colleagues examined functional connectivity during reward processing in adolescent smokers using the Monetary Incentive Delay task combined with functional magnetic resonance imaging (fMRI). Their results show functional connectivity within frontal structures, associated with inhibition and executive control, as well as ventral striatum, a key region in the reward system, during reward processing, supporting the relevance of these brain regions to adolescent addiction. The article by Anokhin and Golosheykin examined risk for cigarette smoking. The authors analyzed data from an ongoing prospective longitudinal study that recorded event-related potentials (ERPs) from twins between 14 and 18 years of age during a Go/No-Go task. Their results show that developmental abnormalities in frontal neural correlates of response inhibition increase the risk for subsequent cigarette smoking. Finally, the article by Elsey, Crowley, Mencl, Lacadie, Mayes, and Potenza examined three putative risk domains: impulsivity, anxiety, and risk-taking, in relation to specific facets of attentional processes and their underlying neural correlates. In their study, impulsivity and anxiety were evaluated using self-report questionnaires and risk-taking was assessed using the Balloon Analogue Risk Task. Based on an fMRI technique, they reported that in healthy adolescents, differences in the three risk domains were related to differential activation of brain regions during attention tasks under simple, selective, and divided attention conditions.

Behavioral studies

The article by Humphrey and Dumontheil addressed developmental changes in risk/reward processing, cognitive control, and social cognition across early, middle, and late adolescence. A cross-sectional sample and multiple regression methods enabled comparison of performance across cognitive control, perspective-taking, and risk-taking tasks and assessment of whether these cognitive abilities followed distinct patterns of development. The finding that improvements in cognitive control precede maturation of social cognition, together with a trend toward increased risk-taking during early adolescence, is explained within the developmental framework of the neural socioemotional reward and cognitive control systems. The study by Blankenstein, Crone, van den Bos, and van Duijvenvoorde examined the effect of attitudes toward risk and ambiguity on descision making in relation to their development across adolescence. Using a wheel-of-fortune gambling task together with a model-based approach derived from economics, subjective preferences for risky and ambiguous choices were assessed. They found different developmental trajectories for risk versus ambiguity. The article by Sully, Sonuga-Barke, Savage, and Fairchild addressed the familial basis of risk-taking in adolescents with conduct disorder (CD) using the gambling task. Their findings show that participants with CD were more likely to select risky options than their typically developing and unaffected relatives. However, unaffected relatives did not reveal risky decision making, suggesting that increased risk-taking does not have a familial basis. The authors call for further research dealing with causal relationships between risk-taking and shared genetic or environmental risk factors. Finally, the study by Naor-Ziv and Glicksohn examined the relationship between risk for developing an eating disorder (ED; bulimia and anorexia) and cognitive functioning in 150 female adolescents, using a wide range of measures assessing impulsivity, psychological distress, executive functioning, and theory of mind (TOM). They found that while deficits in cognitive functioning (set-shifting) were found in adolescents at high risk for both bulimia and anorexia, impulsivity and TOM deficits were found to be higher in adolescents at high risk for bulimia than in the anorexia group.

Theoretical article

In Leshem’s article, the impulsivity construct is examined through its underlying neural and cognitive foundations from a developmental perspective, with a particular focus on adolescence. Integrating findings from developmental research in this area, the proposed model, based largely on Steinberg’s (2008) dual systems, suggests that different aspects of impulsivity can be grouped into two distinct processes, one mediated by the socioemotional system, and the other mediated by the cognitive control system.

The articles in this issue are the product of cutting-edge research aiming to advance our understanding of the links between the adolescent brain and risky behavior, from a developmental perspective. The topics addressed range from specific clinical dysfunction (conduct disorders, smoking, and eating disorders) to typical cognitive and behavioral functioning (e.g., impulsivity, poor decision making, risk-taking) that may put adolescents at high risk. Our understanding of the links between social cognition, psychological systems, and neural mechanisms of cognitive-control, reward sensitivity, decision making, and risk-taking in adolescents must be grounded in core psychological and neurobiological processes. This issue aims to show how this can be achieved. Apart from the stand-alone value of their contributions, I hope that the articles presented in this issue convey how advances draw on multiple theories, concepts, methods, and domains of research.

In sum, this special issue of Developmental Neuropsychology represents the current state of the field in theory and research on the relationships between neural development, impulsivity, and risky decision making in adolescence, and highlights directions for future research.

I thank Editor-in-Chief, Professor Dennis Molfese, for inviting me to serve as guest editor for this special issue and for his guidance throughout the process. Reading the articles has been a meaningful and absorbing learning experience, and exposed me to the high quality of the researchers working in this field.

I also thank Ms. Marsha Schrader in the editorial office for her careful assistance in the preparation and execution of this issue, and offer my sincere gratitude to the reviewers and authors.