12 minute read
The Journey Home
By Ava Richardson
From an early age, Katrina Poe knew she wanted to be a physician. Little did she know the dream she had to help others would take her home—and then home again.
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“I was in fifth grade when I told my mom I was going to be a doctor,” Poe said. “I can remember her being sick a lot, and we would take trips to Jackson because she would need to go see doctors. At the time, I didn’t know they were specialists, but I was amazed at how well they took care of her. I wanted to take care of people the way these doctors took care of my mother.”
Poe credits her family for encouraging her to apply to Mississippi State University. Her aunt, a woman Poe “adored” and wanted to emulate, graduated from MSU in the late 1970s, and Poe knew she wanted to become a Bulldog just like this admired relative.
“It really was a wonderful experience here,” Poe said. “I was very involved in several organizations at the time. I was a State Strider, Bulldog hostess and resident assistant.” In 1992, the Kilmichael native completed her bachelor’s degree in biological sciences at MSU before going on to medical school at the University of Mississippi Medical Center in Jackson, where she also completed a residency in family medicine.
Reflecting on her time as an MSU student, Poe credits her adviser, Donald Downer, for motivating her and encouraging her to complete her dream of becoming a physician.
Poe recalled how Downer frequently reminded her of how well she was doing in school.
“To hear it from someone within Mississippi State’s College of Arts and Sciences who I admired so much really lit a fire inside of me and there was no stopping me—I was going to medical school,” Poe said.
Upon earning her M.D., she took her skills back home to Kilmichael and practiced as the town’s only doctor for 17 years. Being the only doctor in town was both rewarding and challenging. Poe was on call 24/7, often taking her two young sons with her to work. Poe said she was lucky to have received help from other nurses and caregivers who watched her children while she cared for patients. However, after working in her hometown for nearly two decades, an opportunity arose to return to her educational roots and Mississippi State.
When Poe attended the 2018 Final Four in Ohio, she unexpectedly crossed paths with MSU Vice President of Student Affairs Regina Hyatt. Poe’s husband knew Hyatt through his work as adviser to Kappa Alpha Psi Fraternity Inc., and he introduced the two.
“She asked me if I had thought about coming back to Mississippi State as a staff physician because one of the doctors was retiring soon. So, of course, that piqued my interest. Less than a month later, I was able to apply for the position, and I ended up getting it,” said Poe, who began her post at the John C. Longest Student Health Center in the fall of 2018.
Poe’s inner drive and determination led her to become the youngest and the first African American physician to receive the Country Doctor of the Year award from Staff Care Incorporated in 2005. Upon joining MSU, she became the first female African American physician at the university health center. “It can be funny the way life will treat you,” said Poe, who finds humor in how her path led back to where she began. “I started at MSU, and now here I am, back again. Being able to give back to a school that invested so much time and effort into me is a wonderful feeling, and I am so happy and willing to do that.”
MSU’s Longest Student Health Center treats students and faculty, but also is open to members of the Starkville community. For more information, visit www.health.msstate.edu/ healthcenter or call 662-325-2431.
MSU Cognitive Psychologist Seeks to Uncover Mysteries of Human Vision
By Sarah Nicholas
Consider for a moment the importance of vision sight is the primary conduit through which humanity experiences the world. Whether moving safely from one location to another or connecting with a friend in a crowd, a person’s ability to see shapes his or her life in important ways.
However, “eyesight is just the tip of the iceberg,” said Michael S. Pratte, assistant professor of cognitive psychology at Mississippi State University. “Vision really happens in the brain.”
According to Pratte, more than half of the brain is devoted to processing the visual information streaming in through eyes. For example, when crossing the street,
Pratte said, “You aren’t actively using physics and geometry to turn the patterns of light hitting your eyes into a 3D world while calculating the distances, speeds and trajectories of cars and yourself, and then using all this information to chart a safe path across the street. But, somehow, your brain does all of that for you.”
Despite decades of research, scientists who study the brain don’t yet have a firm understanding of exactly how the brain analyzes and makes sense of the information it receives from the eyes. From his research lab in Magruder Hall, Pratte and his team of undergraduate and graduate students study human behavior and brain activity in hopes of advancing vision science to the point they understand how the brain accomplishes the ability to see, and can apply that knowledge to areas spanning from medical science to military applications.
Pratte, a native of St. Louis, earned his Ph.D. in psychology from the University of Missouri, Columbia, in 2010. He then worked as a postdoctoral fellow at Vanderbilt University until 2015 before joining the MSU faculty the same year as an assistant professor in the Department of Psychology.
TOOLS OF THE TRADE
Pratte employs several experimental methods to study the human visual system, including electroencephalography (EEG) and functional magnetic resonance imaging (fMRI), in collaboration with the MSU Institute for Imaging Technologies.
EEG electrodes (Figure 1) measure the tiny electrical signals that occur on the scalp when the brain is active. “EEG lets us measure exactly when something happens in the brain,” said Pratte, “but measurements on the outside of the head cannot tell us precisely where in the brain the neural activity is occurring.”
That’s where fMRI comes into play—an fMRI scanner measures the small changes in blood flow that occur inside the brain. “When you use a specific part of your brain, the body sends blood to that area,” Pratte said. “An fMRI allows us to measure this blood flow,
revealing what parts of a person’s brain are being used while they perform various tasks.”
Thanks in part to fMRI research, scientists know that different parts of the brain have different jobs. However, more recent use of the technology has advanced beyond simply understanding which brain areas are active. “By using modern mathematics, we can now use this measured brain activity to determine what you are seeing and even what you are thinking,” Pratte said.
Take color, for example. With the data from an fMRI scan, “we can figure out what color you’re seeing from the patterns of brain activity in brain areas that process color,” Pratte said. “And even if your eyes are closed, we can identify what color you’re thinking about by measuring activity from those same areas.”
Modern neuroscience technology has much more to offer beyond “cool mind-reading tricks,” Pratte said. “Data from fMRI scans can help neuroscientists better understand how different areas of your brain work to accomplish the incredible feat of seeing.”
Pratte said, “Our brains usually hide the difficult problems of vision, making the act of seeing seem far easier than it really is. For example, at a surface level, it seems easy enough – routine, even – to determine the color of an object. But even that seemingly simple task requires a great deal of processing, most of which happens outside of our awareness or our control.”
(Figure 2a)
(Figure 3a)
This hidden processing can be made more apparent through visual illusions, such as the multi-colored cube in Figure 2a. For most people, the top middle square of the cube appears brown, and the middle square on the side of the cube appears orange. The illusion lies in the fact that those two squares are in reality the exact same color (Figure 2b).
To determine the color of a square, the brain first measures the color of the light that is reflecting from it. However, Pratte said that’s just the start. “It must also figure out where the light is coming from in the image (the top-right, which you somehow just know), the
(Figure 3b)
Answer: The apple and banana were tossed in the air for the photo. The light in the background is ‘non-gelled’ (a light with no filter) for both photos. But in Figure 3a, the light on the fruit has a red gel filter. Since the fruit is in the air, the red filter only hits the fruit while leaving the background natural. Our brains get a bit uncomfortable seeing an unexpected color on a subject we assume we recognize.
color of the light illuminating the cube—perhaps yellow sunshine or blue moonlight—and whether changes in lighting within the image are due to variables, such as shadows or reflections. Only by putting all this information together can the brain determine the color of the square. And whatever color it decides, that’s what you see.”
Pratte said that the most difficult part of his work is ignoring his own visual experience, because “our conscious perception is the end result of a lot of brain processing, but my job is to look past the end, and uncover the steps that led up to it.”
“Our brains do this kind of work constantly and without any effort on our part,” Pratte said. His goal is to study visual processing, and he suggests that brain imaging can provide valuable information about how these kinds of under-the-radar computations are actually working.
Pratte said if he were to ask someone to look at the orange square while their brain activity is being measured, he could use that data to help determine which parts of the brain “are merely processing the light measured by your eyes, and which brain areas are doing the really hard jobs, like making the square orange to account for lighting and shadows.”
WELL-DRESSED/NICE SUIT/ CARES ABOUT APPEARANCE/ PROFESSIONAL
CUP/MUG POSSIBLY COFFEE OR TEA/LIKELY HOT
PEN/PAPER
-ATTENDINGGREETING/SHAKE HAND
CELL PHONE/KEPT CLOSE/LIKELY FOR WORK OR WAITING FOR CALL LAPTOP/OPEN/WORKING
STUDYING THE BRAIN’S LIMITATIONS TO UNDERSTAND ITS POWER
Although human brains can accomplish remarkable feats, Pratte said the brain does have limits for what it can accomplish at any given moment.
“Your brain is always receiving massive amounts of information from your eyes and from all of your other senses,” Pratte said. “But if you were aware of this constant flood of data you would be completely overwhelmed.”
Fortunately, Pratte said, “Your brain uses attention to filter the incoming information, such that you are aware of only a tiny fraction of it. For example, sensors in your big toe are always sending signals to your brain about pressure, but you are not aware of how tight your sock is unless you actively pay attention to these signals.”
“The limitations imposed by attention provide a striking example of how little scientists actually know about what our brains are doing,” Pratte said. “When we look around it feels like we’re seeing everything in front of us, but that’s because your brain can only process a small fraction of that visual information at a time. It’s actually processing little pieces of visual information, and then stitching them together to give you the impression of a coherent visual world.”
Pratte and collaborators have demonstrated that almost every part of the brain involved in vision is affected by “what you are attending.”
“A major goal in psychological science is to understand how the brain does this attentional filtering. How does the filter work? Where does it happen in the brain? And what happens to all of that information that was sent to your brain but never reached awareness?”
“If an engineer was asked to build a computer-based brain that had something like attention, they would probably put a filter somewhere in the middle that only lets the most important information through,” Pratte said. “But that’s not at all how the brain works—almost every part of your brain changes how it processes information in complex ways depending on what you’re attending.”
BRAINS VERSUS MACHINES
Pratte said differences between how the brain works and how computers currently work is “one of the most exciting aspects” of making new discoveries about the brain.
“If we can figure out how the brain does things like read a sentence or drive a car, these same processes could be built into computers,” he said. “Although computers have advanced tremendously in recent years, even our best technology is nowhere near what your brain is capable of doing.”
For example, technologies like Siri and Alexa have become good at recognizing words, but Pratte said they still can “fail miserably in noisy rooms where you would have no trouble following a conversation.”
“And these computer programs certainly don’t understand those words in the way you do, building them into concepts, stories and ideas,” Pratte said.
Pratte also studies very specific tasks where computers currently fail but humans excel, with the hope that “computers might eventually make us better at these critical jobs.”
“There are several military applications, such as our amazing ability to break the visual camouflage of an enemy in combat, where computers can be easily fooled,” Pratte said. “Similar problems exist in the field of medicine.”
“When you get a scan of a broken bone, or a sample of tissue is taken to test for a disease such as cancer, these images are sent to experts who look at them to determine whether you have a disease and what type,” Pratte said. “It takes many years to train a person to be effective at this job, and there is a lot of variability in how good any individual might be. To date, computers have been terrible at these tasks. But if we can understand how a radiologist sees that a bright spot is in fact cancer, or a pathologist knows that something about a particular sample is abnormal, then we could use computers to have more reliable diagnoses, and ones that are available across the world.”
“Can we build computers that do that?” Pratte said. “Can we build computers that can listen and talk or identify cancer? Probably not until we have a much better understanding of how our brains are able to do all of these things so well.”
