ABSTRACT

What makes one person different from the next? In large part it’s that our individual brains are wired a bit differently; each neuron in each person’s brain has a different set of synapses connecting to a different set of neurons. When we’re born, most of the major functional subregions of the brain and their interconnections are in place, but various experiences and environmental exposures affect which synaptic connections become stronger and which become weaker. Different areas of the brain have this synaptic plasticity-or ability to grow stronger or weaker connections-at different time periods, and the timing of these “critical periods” is tightly regulated.