The answer is prefrontal cortex. To simplify, the top of synaptic overproduction in the prefrontal cortex takes place at around one year of age. The prefrontal cortex is the area of the brain where higher-level thinking and self-regulation occur. In addition, the prefrontal cortex is a part of the brain situated at the front of the frontal lobe. It is concerned in a diversity of complex behaviors as well as planning and greatly contributes to character development in which the prominent version of prefrontal cortex purpose is that single neurons within the prefrontal cortex uphold illustrations of task-relevant stimuli in working memory.