A Critical (Sensitive) Period for Learning: The Imaging Study
- Scanned 29 epileptic children ranging in age from 5 days to 15 years.
- Measured the rate of glucose uptake in subjects resting brains.
- Found that glucose uptake reached adults levels at age 2 years, reached twice adult levels at age 3 to 4 years, and began to decline at age 9, and stabilized at adult levels by the end of the teenage years.
- Concluded: Our findings support the commonly accepted view that brain maturation in humans proceeds at least into the second decade of life.
- Argued that synapses require glucose for energy, changes in levels of glucose uptake are temporally correlated with measured changes in synaptic densities, thus indirect evidence for rapid synapse formation followed by synapse elimination at puberty.