Adolescence as a neurobiological critical period for the development of executive function

Bart Larsen

In addition to pronounced physical development, adolescence is a time during which executive functions and cognitive control are reaching adult-like levels. Particularly, adolescence is a period of reduction in behavioral variability and increase in reliability of performance. Concurrently, association cortices which support executive functions, like prefrontal cortex, undergo a series of cellular- and circuit-level changes that facilitate cortical plasticity and result in reliable and efficient neuronal communication. In many ways, these neurobiological changes reflect the mechanisms of early sensory system critical periods that have been extensively studied in animal models of development. Here, I synthesize this literature to present a view of adolescence as a late-occurring critical period of development during which cortical cellular and circuit level maturation of association cortices drives the maturation of executive functions to adult-like levels. I will also discuss how these neurodevelopmental factors are implicated in disorders, such as schizophrenia, which emerge during adolescence and are associated with impaired executive function.

Understanding Difficulties with Math: The Interplay between Math Anxiety and Numerical Processing

Emily Braham

Why do many people underperform in mathematics? In the emotion literature, a substantial body of research attributes low math performance to math anxiety—a negative emotional reaction to situations involving numbers or math. In the cognitive literature, recent research focuses on linking people’s math difficulties to how they process numerical quantities. One system for processing numerical quantities, the approximate number system (ANS), can be used to make intuitive estimates and comparisons about the number of items in collections without counting (e.g., deciding which carton has more blueberries at the grocery store). Many studies find individual differences in ANS acuity to relate to math performance; however, others report null or mixed results. Researchers’ attempts to explain the contradictory findings in the literature have largely ignored the emotional components associated with thinking about or performing math. To address this gap, we gave 87 undergraduate students assessments of ANS acuity, math anxiety, and three different mathematical skills. For certain mathematical skills, there was a positive association between ANS acuity and math for participants who were higher but not lower in math anxiety. Thus, it appears that the relation between ANS acuity and some mathematical skills changes with varying levels of math anxiety. It is rare that numerical cognition researchers consider the impact of affective factors when studying mathematical ability, and our exploration of math anxiety as a moderating variable may help to explain some of the mixed findings in the literature.