Stimulated pathway
Unused synapse
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A childhood brain doesn't grow smarter simply by adding connections — it grows smarter by removing the right ones. This simulator builds a 3D neural network with a realistic developmental arc: an early overproduction phase floods the cortex with candidate synapses, followed by decades-long activity-dependent pruning that keeps whatever is repeatedly used — three highlighted pathways representing language, motor and visual circuits — while eliminating the connections nothing exercises. Scrub the developmental-age slider from birth to adulthood, or press play to watch it unfold, and use the stimulation and pruning-aggressiveness controls to see how environment and individual variability change which wiring survives.