A boy who had large parts of the right side of his brain removed due to a slow-growing tumor made a nearly full recovery in the three years after his surgery, with other areas of his brain compensating for the loss, researchers reveal this week in Cell Reports.

Their case study highlights the brain’s tremendous ability to adapt to such losses and will help researchers better understand how, exactly, parts of the brain can accommodate such losses, the researchers write.

The boy, identified as UD in the case study, was a healthy, normal kid—up until he suddenly suffered a seizure at age four. He subsequently developed intractable epilepsy due to the tumor. When he was nearly seven years old, his parents and doctors made the tough decision to surgically remove the mass. That also meant removing the entire right side of his occipital lobe and part of his temporal lobe on his right side. Together, the extracted sections accounted for a third of the right hemisphere of UD’s brain.

The occipital lobe is one of the four major lobes of the cerebral cortex, the thick outer layer of gray matter covering our noggins’ hemispheres. The occipital lobe sits in the very back of the brain. It’s responsible for processing visual information from the eyes and linking the resulting images to memories. Both the right and left sides of the occipital lobe work together to process visual input, but the right side of the lobe handles input from the left side of our field of vision, while the lobe’s left side processes what we see in the right side of our visual field. The two sides of the lobe also have slightly different strengths in terms of visual processing; the right side is heavily involved in recognizing faces, while the left dominates in identifying written words.

The other lobe affected, the temporal lobe, is another of the four major lobes and borders the occipital lobe on the bottom of the cerebral cortex. This lobe processes auditory information and helps integrate memories with sounds and other sensory information.

After the surgery, doctors and researchers weren’t sure exactly how UD’s brain would handle losing such key visual and recognition regions. Of the two extreme possibilities, one was that his brain’s networks wouldn’t reorganize at all to compensate for the loss, and UD would have severe visual and sensory processing disabilities. The other extreme hypothesis was that UD’s brain would completely compensate, with other regions taking over the roles of the right sides of the occipital and temporal lobes, leading UD to function completely normally.