Man Without Cerebellum In Brain Has Helped Research Into Thought And Emotion

This man never had a full brain, though he makes full efforts to live a good life, with a full name: Jonathan Keleher.

The 33-year-old is among a few people who never had a cerebellum. His brain contains only about half its required neurons.

As he is afflicted by an excessively rare condition, Jonathan speaks and walks in a somewhat awkward manner. He can also not ride a bicyle---because he cannot get the balance.

Yet, he has always been living on his own, working in an office and communicating in a charming manner.

"I've always been more into people than anything else," Jonathan says. "Why read a book or why do anything when you can be social and talk to people?" he says.

Jonathan is an important addition to neuroscience also. He permits scientists to study him as well as his brain, and has given scientists rare insights into the role of the cerebellum. Patients who have suffered a stroke or disease get helped by the research into his brain.

Dr. Jeremy Schmahmann, a professor of neurology at Harvard and Massachusetts General Hospital, says that for decades, the cerebellum has been the "Rodney Dangerfield of the brain." As most scientists are aware only of its role in balance and fine motor control, it seems to be a sidelined section that gets no attention.

However, when you watch an alcoholic, you can figure out that it has a fairly important function. "The state trooper test is a test of cerebellar function," Schmahmann says. "So the effect of alcohol on cerebellar function is identified by everybody who's ever done walking a straight line or touching their finger to the nose."

The cerebellum is linked to brain areas that uses language, reads maps and plans. But a few years ago, functional MRI studies showed the active involvement of the cerebellum in such tasks.

"The big surprise from functional imaging was that when you do these language tasks and spatial tasks and thinking tasks, lo and behold the cerebellum lit up," Schmahmann says.

Jonathan's brain problem showed that one major role of the cerebellum is to refine the art of balance. "It doesn't make things. It makes things better," Schmahmann says.

However, the other major breakthrough that he has helped to achieve is that of understanding the role of cerebellum in emotional processing. "What we now understand is what that cerebellum is doing to movement, it's also doing to intellect and personality and emotional processing," Schmahmann says.

Without a cerebellum, a person's thinking and emotions can become clumsy. While driving, Jonathan found at a busy intersection, that he could not manage to balance his car at a busy intersection. "Reaction time, not my strong suit," Jonathan says.

He is also not introspective, nor can he understand emotional complexity, says Sarah Napoline, his sister. "He doesn't really get into this deeper level of conversation that builds strong relationships, things that would be the foundation for a romantic relationship or deep enduring friendships," she says.

He also needed extra lessons on certain actions that normal people take for granted, such as how to speak clearly, how to behave in social situations and how to show emotion.

Yet Jonathan, through sheer resilience and practice, has picked up some of these skills over the years, Schmahmann says, according to npr.org.