Researchers are now exploring how brain regions develop as our ability to store memories improves during childhood.
Located deep in the middle of the brain, the hippocampus plays a key role in forming memories. It looks something like two curving fingers branching forward from a common root. Each branch is a folded-over structure, with distinct areas in the upper and lower fold.
Recently, Joshua Lee, a graduate student at the UC Davis Department of Psychology and Center for Mind and Brain, Professor Simona Ghetti at the Center for Mind and Brain and Arne Ekstrom, assistant professor in the UC Davis Center for Neuroscience, used magnetic resonance imaging to map the hippocampus in 39 children aged eight to 14 years.
Looking at three subregions - the cornu ammonis (CA) 1, CA3/dentate gyrus and subiculum - they found that the first two expanded with age, with the most pronounced growth in the right hippocampus. Only in the oldest 25 percent of the children, within a few months either side of 14, did the sizes of all three regions decrease.
When they tested the children for memory performance, children with a larger CA3/dentate gyrus tended to perform better, they found.
The study has been published online in the journal Neuroimage.