Campus & Community

Brain may have two minds of its own

7 min read

Researchers study novel ways to ease depression

Scenes seen through the visual field of the right eye register as nerve impulses in the left half of the brain and vice versa. Fredric Schiffer has found that goggles that limit vision to what the outer half of the right eye sees, register images in the left hemisphere. Unexpectedly, such a view seems to alter the emotional views of some people. (Staff photo by Rose Lincoln)

Fredric Schiffer has invented glasses that let him look into some people’s minds. Through using them, he has shown that some patients with depression and post-traumatic stress syndrome see the world differently, depending on whether they look at it through the outer half of their left or right eye. The Harvard Medical School psychiatrist has helped many such patients with the aid of goggles that block either the right or left visual field.

“But I don’t do goggle therapy,” Schiffler says firmly. “The glasses are just a tool I use as an adjunct to traditional psychotherapy. They sometimes assist in freeing a patient who gets stuck at a certain point in therapy, and they can be useful in providing insights to a patient about his or her problems.”

Schiffer believes this is because people’s brains contain two minds or personalities. Each mind is associated with either the left or right side of the brain. “When the two are cooperative, a person feels healthy,” he explains. “When one is immature or somehow troubled, usually by past traumas, the troubled side can lead to mental illness or to self-destructive behavior. The goal of my psychotherapy is to help the troubled side, and the goggles often aid me in doing this.”

Human brains are split into two hemispheres, which much research has shown can represent two states of mind. Due to some strange, unexplained quirk of evolution, scenes seen through the visual field of the right eye register as nerve impulses in the left half of the brain and vice versa. Goggles that limit vision to what the outer half of the right eye sees, register images in the left hemisphere. Unexpectedly, such a view seems to alter the emotional views of some people.

One depressed patient, for example, rates himself as “friendly and important” while seeing the world through his right visual field. When he looks at the world through his left visual field, he rates himself as helpless, lonely, and sad. Said another way, the two parts of a brain can give people different opinions of themselves. Schiffer and others have found that some patients have a left hemisphere with diminished self-esteem, and a right hemisphere with an inflated self-image.

Magnetic heading

Working with Alvaro Pascual-Leone, an associate professor of neurology at Harvard Medical School, Schiffer was able to put his observations to a novel test. Pascual-Leone, who works at Beth Israel Deaconess Medical Center in Boston, treats depressed patients by stimulating their brains with small electric currents. He holds a wand-like device with loops of wire over the front side of their heads. Rapidly changing electric currents in the wand generate a magnetic field that penetrates the skull and induces minute electric impulses in the brain. By activating the left side of the brain in this way, Pascual-Leone and his colleagues are able to lift the burden of bad feelings from the minds of depressed people.

There’s one problem with this technique, however: It’s only successful in about half of the patients. Schiffer, who works at the Harvard-affiliated McLean Hospital in Belmont, Mass., told Pascual-Leone that he thought he could predict which patients would benefit from transcranial magnetic stimulation (TMS), as the procedure is known. Those with depression rooted in the right side of the brain would benefit from left-side stimulation. Those with troubled left hemispheres would not be helped by electromagnetic activation of that hemisphere.

The researchers tried this on 37 depressed patients. When they wore the goggles, 35 felt better looking in one direction rather than the other. For 20 of them, the right visual field provided the most soothing view, indicating that their troubles were associated with the left side of the brain. The other 15 apparently have an illness linked with the right brain. Both groups received left hemisphere activation for 30 minutes every day for 10 days. All patients took standard tests that measured the severity of their depression before the TMS and two weeks afterward.

Seventy-five percent of those believed to have a healthier left brain said they felt improved with magnetic stimulation of that side of the head. Test scores showed they had a 42 percent decrease in the severity of their depression. (Fifty percent reduction is considered a remission of the illness.) Those in whom the goggles revealed a depression associated with the left hemisphere, and received left side TMS, showed only an 11 percent gain. That was consisted a failure of the treatment. These findings were published in the March issue of the scientific journal Neuropsychiatry, Neuropsychology, and Behavioral Neurology.

“Responses to the goggles strongly predicted the outcome of the TMS treatment,” Schiffer points out. “Therefore, these results might be used to fortify current TMS procedures by predicting which individuals with depression will most benefit. They also bolster my dual brain hypothesis.”

Looking the other way

Schiffer does not claim that his work has produced a scientific breakthrough. “In my private practice, only about a third of my patients have shown a strong enough response when wearing the goggles,” he admits. “But in these people they are extremely helpful.”

Of those who do well, about 60 percent of depressed patients feel better when they look at the world with their right visual field (left brain). For most patients with post-traumatic stress syndrome, improvement comes from a look out the left visual field (right brain), indicating that the left part of the brain seems to be the troubled side.

In the tests with magnetic stimulation, right-handed men showed the most predictable results, while left-handed women were least predictable. This result suggests differences based on sex and handedness, but more studies with a larger number of people are needed to determine if such differences hold up.

To better understand what is happening, Schiffer has begun to track blood flow in the brain when patients wear goggles. The flow is measured by a technique in which laser light passes through the skull and records changes in blood flow in each side of the brain. He also is using functional magnetic resonance imaging (fMRI) to scan the brain for changes in activity caused by wearing the goggles. Finally, he plans to see if the goggles can be used to help people with drug-abuse problems.

Schiffer has asked fellow psychiatrists to try his goggles as part of patient treatments, and says he has “files full of e-mail” from those who have had positive results. “But that’s not hard scientific data,” he notes. He also admits that, so far, academic and government researchers have not shown much interest in his results or in his theory of two minds.

Schiffer describes patient reactions to the goggles and gives details about his theory in “Of Two Minds,” published by The Free Press in 1998 “The important thing,” he insists, “is to find out if the theory is correct or not. It all goes to how the mind works and how to treat it when it’s not working right.”

He might have said “when it’s not looking right.”

Every man takes the limits of his own field of vision for the limits of the world. – Schopenhauer