Although neuroscience research has debunked the late 19^th century claims suggesting that large portions of the brain are typically unused, recent evidence indicates that an enhanced understanding of neural plasticity may lead to greater insights related to the functional capacity of brains. Continuous and real-time neural modifications in concert with dynamic environmental contexts provide opportunities for targeted interventions for maintaining healthy brain functions throughout the lifespan. Neural design, however, is far from simplistic, requiring close consideration of context-specific and other relevant variables from both species and individual perspectives to determine the functional gains from increased and decreased markers of neuroplasticity. Caution must be taken in the interpretation of any measurable change in neurobiological responses or behavioral outcomes, as definitions of optimal functions are extremely complex. Even so, current behavioral neuroscience approaches offer unique opportunities to evaluate adaptive functions of various neural responses in an attempt to enhance the functional capacity of neural systems.