By Bob Nosbisch
Mysteries of the Mind and Brain
Jim Kroger, an assistant professor of psychology at New Mexico State University, conducts research in cognitive neuroscience, splitting his time between NMSU and the MIND (Mental Illness and Neuroscience Discovery) Institute, a federal lab on the University of New Mexico campus.
At the MIND Institute, Kroger uses functional Magnetic Resonance Imaging (fMRI) and Magnetoencephalograms (MEG) to observe the brain’s activity. By watching function and thought processes of the brain, he studies which brain parts are doing which parts of the thinking.
“So there are things like recalling some rules or knowledge from long-term memory, processing what you’re looking at or what language you’re hearing, and the fMRI lets us see all that function inside,” Kroger said.
However, the fMRI lacks precision in determining when events happen, which is sometimes important to know, even down to the millisecond, “because that’s how fast the brain works.”
By using electroencephalographs (EEGs) at NMSU, Kroger can study this critical aspect of brain activity.
Focus on frontal lobes
The brain’s frontal lobes fascinate Kroger, who says scientists did not focus on irrational choices made by humans until the 1970s.
“Some people are better at using their reasoning, their frontal lobes, to guide their behavior instead of their more immediate needs,” he said.
People with well-developed frontal lobes will bypass immediate gratification for longterm gain.
But others don’t worry about the consequences of their actions, he said, listing criminals, adolescents, and people who experience certain psychiatric disorders, such as depression, in this category. Emotional urges guide their behavior in a way that brings immediate gratification, but not good long-term results.
Even though scientists have examined the frontal lobes since neuroimaging became popular in the 1980s, Kroger said, “there’s still no agreement on how the frontal lobes are divided up into functional pieces that work together.”
Kroger also is interested in attention – what it is and how we focus our brains on something. He calls the mechanisms for controlling our attention “very sophisticated” and he studies that control by having people perform simple tasks and then switch to different kinds of tasks.
“We’re interested in the instantaneous focus of attention,” Kroger said. “That usually happens in a third of a second. I’m interested in the very first part of paying attention, when you redirect your attention to something.”
By manipulating the levels of difficulty for each task or how soon the second task follows the first, Kroger can study the factors that affect this ability to control our attention.
Brains, computers and interfaces
Brain-computer interfaces, which exploit brain waves to control such things as computers, fighter planes, or prosthetic devices, also are of interest to Kroger. He said interest in this field began in the 1990s and the field has grown, attracting researchers who implant electrodes inside the brain as well as those who “read” mental commands by measuring EEG.
The problem, Kroger said, is that a number of brain wave cycles are required before enough information is available to know what command is being given. He attacks this problem by observing much faster frequencies as he tries to find signatures for the commands that can be quickly recognized.
“Right now, typical brain-computer interfaces take a half second to respond to a mental command,” Kroger said. “You’re not going to have very good control over a prosthesis, computer, or fighter plane if it takes a half second to respond. But we’ve been able to recognize the signature in these very high frequencies in a tenth of a second. So we’re doing better in our ability to recognize things quickly.”
Kroger notes that a better understanding of how the brain functions is critical to understanding what goes wrong in various brain and psychological disorders such as depression and schizophrenia. His research could help point the way to better diagnosis and treatment options for these conditions.