INDIANAPOLIS, Indiana (CNN) -- One night last spring, Conor Mather-Licht was celebrating the end of his freshman year in college. Out to dinner with friends, he started to read the menu, but couldn't.

Conor Mather-Licht, 19, lies awake during surgery to remove a brain tumor.

He saw the pictures, and the words, but he just couldn't comprehend what was in front of him. The feeling lasted just a moment, but he knew something was wrong.

When he returned home to Indianapolis, Indiana, a few days later, he mentioned the episode to this parents. They took him to the doctor immediately. The diagnosis wasn't good.

Mather-Licht had a brain tumor, known as a glioma, situated above his left ear. Not only was it causing severe headaches, which he had attributed to everyday stress, but the tumor was pressing on the area of the brain that controls the ability to read and speak. It needed to come out.

Because of his age, Mather-Licht's doctors suspected that his tumor was benign. But they needed a biopsy to make sure, and the tumor needed to come out.

Because the tumor was located in a very delicate area of the brain, his surgeon recommended a procedure called "awake craniotomy with mapping." It's much like standard brain surgery, with one critical difference: The patient is awake.

The brain is a map, said Mather-Licht's neurosurgeon, Dr. Aaron Cohen of Methodist Hospital in Indianapolis. Different areas help us read, walk, talk, even cry and smile.

So if a tumor is located in a crucial part of the brain, as in this case, doctors perform surgery on patients who are awake in order to see what functions the surgeon may be affecting while eradicating the tumor.

CNN was allowed to be present during the surgery. Dr. Sanjay Gupta reports on Conor Mather-Licht's awake brain surgery »

During the procedure, Mather-Licht was heavily sedated but remained conscious so Cohen could talk to him while mapping the brain's sensors. Once Mather-Licht's skull cap -- a large chunk of bone from his head -- was removed, he remained alert even though his brain was fully exposed.

By communicating with the patient as he gently touched the brain with electrical probes, Cohen could tell what sections were sensitive and needed to be avoided.

Mather-Licht remained attentive through the procedure, actually reading a book by Kurt Vonnegut aloud. If Cohen pressed on a sensitive region, Mather-Licht's reading was affected, which let the neurosurgeon know it was an area to avoid.

Health Library MayoClinic.com: Brain tumor

The mapping alone took a couple of hours. Based on the information entered into a computer during mapping, the "hot spots" or risky areas, were displayed on a monitor. Once mapping was complete, Cohen took a paper list of groups of letters that represented basic brain functions, such as expression and movement.

With a pair of scissors, a nurse cut out the letters that corresponded to Mather-Licht's "hot spots." Cohen then placed the lettered pieces of paper directly on Mather-Licht's brain, distinctly identifying the areas of risk. Once those were marked, he opened the brain's outer membrane and, layer by layer, removed the tumor. Mather-Licht felt no pain -- the brain itself has no pain receptors.

The entire procedure lasted about five hours. After the skull fragment was put back in place, Mather-Licht was wheeled into his hospital room, still conscious, but exhausted.

It took Mather-Licht about a week and a half to recover. Most patients stay only a few days in the hospital. But because his tumor was relatively large, his recovery took longer.

At first he had difficulty speaking, mini-seizures and trouble reading. Little by little, as his brain healed, he regained all his functions. And the best news was that his tumor was benign, which meant he wouldn't need chemotherapy or radiation.

This month, Mather-Licht is preparing to return to college. This year, he'll have quite a story to tell about what he did on his summer vacation.