Resources We Offer
NCRRN Funded Pilot Projects
- Chris Hamilton, PhD
- Postdoctoral Fellow, Department of Neurology, University of Pennsylvania, Philadelphia, PA
-
-
Manipulating Effects of Proactive Interference in Left Inferior Frontal Gyrus with Transcranial Magnetic Stimulation
-
An emerging body of research suggests that executive control processes, assumed to be localized to the left inferior frontal gyrus (LIFG), may have important implications for working memory (WM) and language processing. For example, it appears that lesions to LIFG result in deficits in resolving interference in WM, as well as language production and comprehension.
The principle aim of the present proposal is to better elucidate the functional and anatomical organization of LIFG using transcranial magnetic stimulation (TMS) and to acquire sufficient pilot data to propose a more extensive program of TMS research. I have secured IRB approval for the proposed experiment in collaboration with Sharon Thompson-Schill, Ph.D. and H. Branch Coslett, M.D. This proposal would allow collection of pilot data to be included in a proposal for a Ruth L. Kirchstein National Research Service Award for Individual Postdoctoral Fellows (F32).
This experiment is formulated to address several specific questions:
1. Is the pars triangularis causally involved in the resolution of proactive interference in WM?
2. Is the pars triangularis necessary for the mere detection of conflict/ interference in WM or, alternatively, might the pars triangularis represent an "active-reset" mechanism that deletes no longer relevant representations from WM?
Finally, having identified a region of pars triangularis that mediates resolution of proactive interference, data from the proposed experiment will be used to formulate further research. These studies will determine whether stimulation of the pars triangularis also undermines the resolution of semantic and phonological interference in a similar WM paradigm, as well as examining interference in language production and comprehension.
- Jared Medina, PhD
- Department of Neurology, University of Pennsylvania, Philadelphia, PA
-
-
Neural Correlates of Kinematic Motor Learning
-
When learning a motor task, people develop internal models that convert desired limb trajectory into a set of muscle commands. Current evidence suggests that dynamic motor learning (during which subjects learn a motor task while force is presented to the limb) and kinematic motor learning (during which the relationship between the visual target and the movement itself is distorted) involve separate memory systems. However, little research has been done to investigate whether there are different neural substrates for dynamic and kinematic motor learning. We propose to use transcranial magnetic stimulation to investigate the neural substrates of the acquisition stage of kinematic motor learning.
- Sarah Shomstein, PhD
- Post-Doctoral Fellow, Department of Psychology, Carnegie Mellon University, Pittsburgh, PA
-
-
Examining the effects of prismatic adaptation therapy on visuo-spatial neglect
-
A number of recent studies employed a very interesting technique - prism adaptation - in hopes of increasing attentive behaviors (e.g., reaching) toward the neglected side in patients with visuo-spatial neglect. It was observed that after a brief period of wearing prism glasses, that visually shift all the relevant information several degrees rightward (i.e., what used to be on the left side is now on the right side), patients showed increased exploratory behaviors toward the previously neglected side even once the glasses were removed. Presumably, what allowed patients to explore the left side is that after the removal of the adaptation glasses the information was shifted several degrees to the left. What sets this intervention apart from the previous attempts to alleviate unilateral neglect is the observation that the effects of adaptation could generalize across several different clinical measures of unilateral neglect, including wheelchair navigation, postural control, and neglect of mental imagery. In addition, it was observed that the effects persisted as long as 4 days after a single adaptation procedure4. Longer lasting effects (as long as 5 weeks) were even reported following an intensive twicedaily adaptation program during a 2-week period5. These observations suggest that, even after acquired brain damage, short term exposure to prismatic adaptation is sufficient to stimulate a relatively longer-term reorganization of the neural representation (or effects) of space that develops without awareness after removal of the prisms.
The generalization and long-standing effects of prism adaptation make it a potential therapeutic treatment of choice and has revived interest in the neurocognitive mechanisms by which it has been achieved. However, the neural basis for this therapeutic effect in unilateral neglect patients has yet to be formally understood and therefore this remains an important area of investigation.
This pilot study consists of three experiments. The first experiment is designed to understand in fine-grained detail the impairment in information processing that occurs following an infarct that results in visuo-spatial neglect. The second experiment is designed to evaluate the behavioral improvements following the prismatic adaptation rehabilitative intervention. The third experiment is designed to evaluate changes on the neural level (i.e., reorganization following rehabilitative intervention) following prismatic adaptation.
- Shelli Kesler, PhD
- Senior Research Scientist/Lab Manager, Stanford University School of Medicine, Stanford, CA
-
-
Assessment and Rehabilitation of Cognitive Impairments in Pediatric Survivors of Cancer
-
Cancer is the leading cause of death by disease in children under the age of 16. While the incidence of pediatric cancer has increased over the past 20 years, so has the survival rate. With the rising number of children who survive cancer, late effects of cancer and its treatments have begun to receive increased attention. Research shows that approximately 30% of children treated with chemotherapy experience some degree of cognitive impairment, primarily in executive functions. It is unclear what makes the subgroup of pediatric cancer survivors more vulnerable to experiencing cognitive-behavioral impairments. Some studies suggest that cognitive impairments in pediatric cancer survivors may be progressive and thus research that improves our ability to prevent and/or intervene in cognitive-behavioral outcome for these children is essential. Specifically, we must more precisely define the neuropsychological and neurobiologic profiles associated with cognitive dysfunction in pediatric cancer survivors.
- Andrew Robert Mayer, PhD
- Research Scientist, The MIND Institute; Adjunct Assistant Professor of Neurology, University of New Mexico Hospital
-
-
Multimodal Neuroimaging of Attentional Deficits in Mild and Moderate Traumatic Brain Injury
-
Investigate acute attentional dysfunction and subsequent neuronal recovery (at approximately 3-5 months post injury) in a cohort of mild to moderate traumatic brain injury (TBI) patients and matched controls. The impact and innovation of this proposal lies on several levels. Foremost, it addresses an important gap in our current knowledge regarding the development of standardized protocols that are capable of capturing the dynamic nature of brain injury. Routine clinical imaging modalities (MRI and CT scans) are usually insensitive to both the neuronal pathology underlying acute cognitive deficits as well as to the subsequent recovery process in the majority of mild TBI cases and in a minority of moderate TBI cases (Belanger et al., 2007). It is likely that the underlying pathology is multifaceted and involves both white and gray matter, suggesting that sampling several different domains of neuronal integrity is a necessary first step to understanding the acute cognitive deficits as well as the normal recovery process. To date there have been a paucity of methodologically sound studies that have utilized more research-based neuroimaging techniques to map both attentional deficits and their subsequent recovery in mild to moderate TBI. Therefore, the utility of multimodal imaging in mild to moderate TBI remains an empirical question.