MRRI Scientist Studies How the Brain Processes Language to Learn about Stroke

Edward Wlotko, PhD, has been studying how the brain processes language since he was an undergraduate at the University of Pittsburgh. And his interest in language comprehension—particularly how the two hemispheres interact to make that happen—deepened in graduate school, at the University of Illinois at Urbana-Champaign. There, he devoted his dissertation work to understanding the differences in how language is processed by each hemisphere of the brain, the two sides working separately and in tandem.

Edward Wlotko, PhD

Before coming to Moss Rehabilitation Research Institute, Dr. Wlotko completed two post-docs, one at the Beckman Institute for Advanced Science and Technology at the University of Illinois, the other at Tufts University.

“In my first post-doc,” says Wlotko, “I studied language in the aging brain. At Tufts, I used neuroimaging to study college-aged adults’ language comprehension. So when I got to MRRI I wanted to combine and extend these areas of research from my past work.”

Now, as director of the MRRI Cognitive Neurophysiology and Neuropsychology Lab, Wlotko is trying to further understand how language works in healthy brains to ultimately help problems with language caused by stroke. For example, mapping what facets of language comprehension and production are governed by the two sides of the brain will provide clues to the kind of language or communication difficulties someone might experience after a left vs a right hemisphere stroke. Wlotko believes it is important to approach this question from both angles: Learning about the healthy brain helps researchers understand what happens in the damaged brain—and learning about what’s going on during stroke helps researchers understand more about the healthy brain.

One of Wlotko’s focus areas is how the left and right hemispheres use context differently during normal language comprehension. The two sides serve fundamentally distinct purposes in language comprehension, but both are necessary. “The main project I’m getting up and running here at Moss is continuing to look at hemispheric differences,” says Wlotko. “The left hemisphere is good at using context predictively – knowing what’s coming next. The right hemisphere doesn’t anticipate what’s coming in that way. It doesn’t care about predictability in the same way, but it has an advantage when it comes to information that’s not predictable, but is nevertheless related and relevant.”

Additionally, he and his team have noticed that not everyone’s brain ages in the same way. “For older individuals who show more age-related change relative to young adults,” says Wlotko, “their brains show similarities with right hemisphere of young adults. But in those who retain younger looking brains, theirs look more like the left hemisphere in young adults.”

To explore how the brain processes language, Wlotko measures the brain’s electrical activity through what are known as event-related potentials (ERPs)—small jumps in electrical activity when the brain takes in information, which can be measured through a number of electrodes placed around the scalp. For example, the brain reacts differently when a stimulus (e.g., a word in a sentence) is predictable, vs. unpredictable. Looking at ERPs, one can compare how the brain processes language in healthy individuals to those who have experienced stroke.

“Here at MRRI,” says Wlotko, “I am using these kinds of experiments to compare language comprehension after left vs. right hemisphere stroke at the group level. But we also hope that this is going to let us learn more about how individual patients differ, which can provide a lot of clues for rehab.”

Wlotko plans to continue working with both healthy and stroke-affected people, and particularly with people of all ages, instead of only young adults, who are the usual participants in this kind of research. “I’m also planning on doing more work in healthy individuals, who haven’t experienced stroke, but who are of different ages. Most of what we know about language comes from college-age samples – not the people who are likely to have a stroke. Since there are age-related changes across the lifespan, we need to see these changes to understand differences between healthy aging and stroke.”

Wlotko looks forward to his burgeoning career at MRRI, and to collaborating with other researchers. Using research to turn theory into therapy is one of the fundamental aims at MRRI, and Wlotko is on board for the challenge.

“I was drawn to MRRI not only because of the strong reputation for theoretically motivated research that simultaneously drives forward our understanding of the brain as well as creates insights for rehabilitation,” says Wlotko, “but also because the resources available at the Institute allow me to add a neuropsychological approach to my research that would be very difficult to do anywhere else. I look forward to further enhancing our understanding of how the two hemispheres of the brain work together.”


MRRI Testing Medication’s Effect on Memory in Brain Injury Patients

People with traumatic brain injuries frequently face problems with everyday memory function – an issue that can limit their recovery.  Tessa Hart, PhD, director of the Moss Rehabilitation Research Institute’s Traumatic Brain Injury Clinical Research Laboratory, is contributing to research that may lead to improved memory in those people.

As part of a four-site study, Dr. Hart’s lab is testing whether the medication donepezil, which is used to treat dementia in patients with Alzheimer’s Disease, can help with memory function in TBI patients. Donepezil is approved by the FDA and is known to be safe, with minimal side effects.

In this video, Dr. Hart provides more information on the study, which is currently recruiting additional research subjects. If you are interested in participating in the study, please call 215-663-6432.


Postdoctoral research training at MRRI

Former fellows reflect on their experiences in the NIH-funded program

For the past five years Moss Rehabilitation Research Institute (MRRI) has been the lead site in a postdoctoral research program funded by a National Institutes of Health (NIH) training grant in translational neurorehabilitation research. Students who qualify for the unique fellowships made possible by this grant are given opportunities to gain exceptional in-depth mentorship and training critical for careers in translational neurorehabilitation research. The training opportunity is offered in collaboration with the University of Pennsylvania’s Department of Neurology and Center for Functional Neuroimaging (Penn).

“The three-year fellowship is an apprenticeship model of training designed to offer mentored experience in meeting the challenges of the translational process,” says John Whyte, MD, PhD, principal investigator and director of the post-doctoral research training program, and founding director of MRRI. “Fellows spend most of their time conducting research in the lab of a primary mentor, but typically also select a secondary mentor. In keeping with our goal of promoting translational research, if a fellow’s primary mentor is largely engaged in basic science, we will encourage that person to have a secondary mentor whose work has more of a clinical focus, and vice versa.” Continue Reading


NIH Grant Aims to Improve Naming in People with Aphasia

Can you recall a time when you couldn’t think of the name for something? Perhaps it was a familiar object you could picture in your mind. The word was “on the tip of your tongue,” but you just couldn’t name it.

Scientists who study language call this experience the tip of the tongue phenomenon. It happens occasionally to people with healthy brains, and it seems to become more prevalent as a part of healthy aging. The phenomenon is more common and persistent for people with aphasia—a disorder arising from brain damage that affects the production or comprehension of spoken, written or gestured speech. Aphasia affects more than one million people in the U.S., most of whom have suffered a left-hemisphere stroke. Continue Reading


Studying Concussions Using Smart Phone App

Physicians trying to manage concussion symptoms face a dual challenge – no way to identify which patients will go on to suffer from persistent concussion symptoms and a dearth of evidence-based treatments.

Amanda Rabinowitz, PhD, director of the Brain Injury Neuropsychology Laboratory at the Moss Rehabilitation Research Institute, is conducting a research study that uses mobile app technology to address this core issue.

In Dr. Rabinowitz’s study, recently concussed individuals use a smart-phone app to record their symptoms at multiple times throughout the day while they go about their daily activities.

As she explains in this video, the ultimate goal is to develop a method for planning individualized concussion treatments.


Hart Receives Award for Lifetime Contributions

Dr. Hart holding award

Tessa Hart, PhD, institute scientist, recently received the Roger G. Barker Distinguished Research Contribution Award at the 2017 Rehabilitation Psychology Conference in Albuquerque, N.M.

The annual Barker award is “conferred upon an individual who is judged to have made an outstanding lifelong contribution to Rehabilitation Psychology through empirical research, conceptual/ theoretical development, or both.” It is named for Roger G. Barker, who was a founder of environmental psychology, which focuses on how social and physical environments influence actions and behavior.

Dr. Hart directs the Traumatic Brain Injury Clinical Research Laboratory as well as the Moss Traumatic Brain Injury Model System. Her research focuses on TBI outcomes and treatments, with special focus on long-term psychosocial outcomes and treatments involving cognitive and emotional self-regulation.


Focusing on Visual Perception to Improve Motor Performance After Stroke

Mirror Therapy

Steven Jax, PhD, has spent most of his career at Moss Rehabilitation Research Institute (MRRI), and doesn’t have plans to leave any time soon. Dr. Jax came to MRRI from Penn State, where he did his doctorate work in basic sensorimotor processing. He began his tenure at MRRI as a post-doc in the lab of Laurel J. Buxbaum, PysD. There, he began his research on rehabilitation in stroke patients, which he’s expanded over the years as director of the Perceptual-Motor Control Laboratory. Continue Reading


Using Mirror Therapy to Trick the Brain’s Motor System

Many people who have had a stroke experience difficulties moving one arm. These problems can significantly affect their quality of life, but treating them is often difficult and many individuals fail to ever recover adequate use of the arm. Improvement for many people who have experienced a stroke is also hindered by limited medical insurance coverage for long-term therapy.

Hope may come for these patients from a technique using mirrors that tricks the brain into thinking it sees both limbs as healthy. Continue Reading


Testing a Treatment for Phantom Limb Pain

Research by Moss Rehabilitation Research Institute and Penn Medicine into a treatment for the phantom limb pain received coverage on a Philadelphia television station recently.

Almost 2 million people in the U.S. have had an amputation. The great majority of those people experience a persistent sensation of the missing limb, known as a “phantom limb,” which is associated with debilitating pain. Current therapies fall short of bringing relief to most of these individuals. Continue Reading


Mapping the Brain’s Tool Use Network

buxbaum_novel_tools_task_650

Imagine attempting to find an everyday kitchen item—for example, a spatula— in a drawer, and then using the spatula to flip a pancake. What if instead of retrieving the spatula, you picked up and used a nearby fork with a spatula-like action? Such errors, in which objects are mis-used during the course of everyday actions, are experienced by thousands of individuals with a disabling and common disorder known as limb apraxia.

For more than two decades, the Cognition and Action Lab at MRRI, headed by Laurel Buxbaum, PsyD, has been making strides in understanding both the neurological deficits and regions of the brain involved in this disorder, as well as the normal cognitive mechanisms that permit successful tool-related actions. Among the lab’s many achievements is the development of a cognitive neuroanatomical model of the processes and brain regions that may govern complex tool-related behaviors. Continue Reading