College of LAS « Illinois

Research

The Bourne Reality

Amnesia research unlocks mysteries of people lost in time.

Amnesia image

Neal Cohen still remembers his days at MIT in the early 1980s, when he would drive a patient known as HM from Connecticut to Massachusetts for testing. HM had no idea who Cohen was or why they were even in the car. That’s because HM, the most famous neurological patient in the world, had one of the most severe cases of amnesia on record.

HM was 27 years old in 1953 when he underwent an experimental surgical procedure to find relief from severe epileptic seizures that struck multiple times per day. The surgery successfully controlled the seizures, but it also left him without an ability to create new enduring memories of facts and events. HM could remember his life through age 16; but as Cohen, an LAS professor, says, “He had poorer memory for the events of his life since age 16 than anyone you will ever meet.”

HM passed away this past year. As for Cohen, he now directs the University of Illinois Amnesia Research Laboratory, where he has been tracking more than 20 subjects over a considerable span of time. He says the most common depictions of amnesia in pop culture are usually off base. In typical TV scenarios, people lose their sense of identity after a severe blow to the head—who they are, who they owe alimony to, or how many kids they have. But according to Cohen, “The loss of identity almost never happens after brain injury.”

The main time you see a loss of identity comes from “psychogenic amnesia,” the kind of amnesia that follows a severe psychological stress or horrific event. These cases are rare and the memories often return quickly, sometimes within a week, he says.

The more common amnesia cases result from structural damage to the brain. When this happens, patients don’t forget who they are, but they are unable to form new enduring memories. Take the case of Lucy (not her real name), a woman whom Cohen studied. After receiving a drive-up flu shot, Lucy had a severe allergic reaction and drove into a tree, resulting in a severe closed head injury and amnesia. She could not form new enduring memories of facts and events.

According to Cohen, Lucy devised one of the best coping plans he had ever seen. She kept meticulous notes in her memory book, which she used to record what she had done during the day as well as other vital information, such as what her car looks like.

Until she devised her system, even simple tasks such as showering could go on forever. Lucy would wash her arm, then wash her hair, and then wash her arm again because she had forgotten she already washed it. Lucy taught herself to use a laminated checklist in the shower and to use very detailed checklists at her job.

Cohen says that movies such as The Bourne Identity get it partly right. In the movie, after a head injury, superspy Jason Bourne loses his identity (wrong), but he retains his superspy skills (right). Cohen’s research has shown that people can retain their skills and learn new skills, even when they cannot form new memories of facts and events.

In the lab, for instance, they teach computer game skills to amnesia subjects, who learn and retain these skills at the same rate as non-amnesia subjects of the same age and intelligence. But when Cohen tells amnesia subjects that they’re “doing great, an improvement over yesterday,” they inevitably respond in puzzlement by saying, “I came here yesterday?”

Cohen’s work has been key to showing that our brain is organized into multiple memory systems, and that damage to certain regions of the brain does not affect all types of memory. Among these systems are declarative memory (the facts and events of our lives), procedural memory (our skills), and emotional memory. Emotional memory enables us to remember fine details of certain emotional events, such as exactly what we were doing during the attacks on 9/11.

Research at the lab has also probed the vital role played by the hippocampus. Specific memories are distributed throughout the brain—the language information in one part, information about people and objects in another, spatial information in another, etc.

“The hippocampus binds these different elements together, so you can remember the whos, the whats, the whens, and in what order,” he says.

“Everything about who we are and how we came to be—that is our memory at work,” he adds. “We’re only in the present at this moment, and then it’s gone. As Tennessee Williams once said, ‘Life is all memory, except for the one present moment that goes by so quick you can hardly catch it going.’”

By Doug Peterson
Fall 2009