Final answer:
Increased synaptic pruning occurs in Ardella's brain during puberty, streamlining neural pathways and enhancing cognitive efficiency.
Step-by-step explanation:
As Ardella begins the process of going through puberty, among the physical changes that will occur in her brain is increased synaptic pruning. This is a process where the brain refines its neural connections based on experiences, helping to increase the efficiency of neural communication. The brain eliminates unused neural pathways, which is believed to contribute to the cognitive development during adolescence. Increased production of sex hormones is also a significant change during puberty, but it occurs not in the brain but in the gonads, as a result of changes in the sensitivity of the hypothalamus and pituitary glands. The prefrontal cortex, responsible for executive functions, does see accelerated development, but this is not characterized by growth per se, rather an increase in complexity and myelination. Decreased gray matter density can be a product of synaptic pruning; however, it isn't indicative of the main change occurring within the brain during puberty.