The procedure was first developed in the 1920s to treat malignant brain tumors. But its success in children who have brain malformations, intractable seizures or diseases where damage is confined to half the brain, has astonished even seasoned scientists. After the procedure, many of the children are able to walk, talk, read and do everyday tasks. Roughly 20 percent of patients who have the procedure go on to find gainful employment as adults.

Now, research published Tuesday in the journal Cell Reports suggests that some individuals recover so well from the surgery because of a reorganization in the remaining half of the brain. Scientists identified the variety of networks that pick up the slack for the removed tissue, with some of the brain’s specialists learning to operate like generalists.

“The brain is remarkably plastic,” said Dorit Kliemann, a cognitive neuroscientist at the California Institute of Technology, and the first author of the study. “It can compensate for dramatic loss of brain structure, and in some cases the remaining networks can support almost typical cognition.”