Chunk #106 — The Theory of Urgency — The Role of Positive and Negative Urgency During Adolescence — Heightened Emotionality and Disposition Toward Rash Action During Adolescence
MRI studies of the structural maturation of the human brain indicate that the prefrontal cortex (PFC) appears to mature last, and not until around age 20, and adolescence is characterized by reduced PFC activity, which likely leads to difficulties in inhibiting impulses, weighing the consequences of decisions, prioritizing, and strategizing among adolescents (Giedd, 2004; Lewis, Cruz, Eggan, & Erickson, 2004; Luna & Sweeney, 2004, Spear, 2000). In addition, there is less integration across brain systems in adolescence: the synaptic pruning and increased myelination that make possible rapid communication among brain regions is not yet as fully developed as it is in adults (Luna & Sweeney, 2004; Spear, 2000). Incomplete brain integration indicates less complete communication between inhibitory and appetitive systems; researchers have referred to this state as “dynamic late maturation throughout the neocortex” (Luna & Sweeney, 2004).
