Resources We Offer
NCRRN Funded Pilot Projects
- Jennifer Thomson, PhD
- Assistant Professor, Harvard Graduate School of Education
-
-
Translational & theoretical possibilities of transcranial direct current stimulation in dyslexia
-
While significant advances have been made in understanding effective methods of remediating developmental dyslexia, at least 30% of children with dyslexia do not respond to these best practices1, with the situation even more serious in young adults2. In this study we aim to examine the potential of using transcranial direct current stimulation (tDCS) to augment both our understanding of the neural bases of dyslexia, as well as its remediation.
We plan two stages of experiments with young adults ages 18-25 that will set the stage for a long-term research and intervention program in children. Ultimately, the most effective interventions will likely be on children who begin reading early and whose plastic brains will respond most malleably to an intervention that would be geared towards remediating the underlying neurobiological disorder
Aim 1a. To examine whether tDCS can affect language abilities in the short term.
Aim 1b. To examine whether tDCS can affect language abilities after a 5-day intervention combining tDCS and intense cognitive-behavioral practice.
Aim 1c. To understand the duration of post-intervention effects.
In the first stage of our research we will apply non-invasive brain-stimulation using tDCS to modulate the activity of the left- and right-hemisphere temporo-parietal cortex, the former being the focal region that instantiates phonological abilities3. Our participants will be young adults with dyslexia. We will assess the effect of cathodal and anodal tDCS stimulation upon phonological processing abilities. Stage two will be a five-day intervention with tDCS and concurrent cognitive-behavioral training. We will use a pre- and post-test intervention design to examine behavioral change associated with remediation.
Aim 2. To examine patterns of functional connectivity between stimulated regions of the brain and other regions that may facilitate or impair language performance.
Our core region of interest is left temporo-parietal gyrus, a region well established as central to phonological processing. TDCS will be used in its two modes to either increase or decrease the regional excitability. However, our protocol also examines the effects of stimulation of the right hemisphere homologue. If stimulation of the right hemisphere homologue improves or impairs performance, this may be because of a change in the level of interhemispheric inhibitory projects from right to left. Understanding such patterns of functional connectivity is important in treating young adult dyslexics, the subjects in our study, and it will lay the groundwork for future studies in child dyslexics, who show patterns of compensation over time.
- James Malec, PhD
- Research Director, Rehabilitation Hospital of Indiana, Indiana University Department of Physical Medicine and Rehabilitation
-
Transcranial Electrical Stimulation (TES) for Mood, Cognitive, Sleep, and Pain Disorders after Traumatic Brain Injury (TBI)
Our research group intends to pursue a line of TES research with goals of: (1) evaluating the efficacy TES for the treatment of depression and associated cognitive dysfunction after TBI; (2) investigating possible relationships among changes in variables of interest, i.e., depression, cognition, anxiety, sleep, pain, and self-reported functional status; (3) evaluating the durability of treatment effects at longer term (3-6 month) follow-up. A definitive study directed at these goals would address specific hypotheses related to each goal:
Hypothesis #1: TES treatment will result in a greater improvement in depression and executive cognitive function than baseline or control conditions.
Hypothesis #2: The rate of improvement and overall improvement in depression will be associated with improvements in the other domains of cognition, anxiety, sleep, pain, and functional status.
Hypothesis #3: Improvement in mood, cognition and functional status will be maintained at longer term (3-6 month) follow-up.
However, in order to establish the foundation to obtain funding for and conduct a definitive study along these lines, we must obtain pilot data and conduct analyses to address several preliminary aims. Aims of the study proposed here are:
Aim #1: Obtain an estimate of the effect size of TES treatment relative to a control condition. Accomplishing this aim will allow us to determine the sample size for a definitive study. Implicit in this aim is also determination of whether the effect size is substantial enough to warrant further study.
Aim #2: Determine the degree to which single-subject and group design and statistical methodologies may be useful in developing a definitive study of TES.
Aim #3: Assess the reliability of measures of variables of interest (depression, cognition, anxiety, sleep, pain, functional status) in the context of this type of treatment study. We have attempted to identify reliable and valid measures. This pilot study will provide data regarding the reliability and sensitivity of each these measures in assessing the efficacy of TES. Of course, a lack of sensitivity may also indicate the lack of a treatment effect. However, examination of the consistency of the measurements over time will provide an indication of whether excessive random variation makes it difficult to identify a treatment effect for some measures.
Aim #4: Estimate the size and pattern of covariance among variables of interest. As stated in hypothesis #2, we expect that treatment-related changes in depression and cognition will be associated with changes in other domains of anxiety, sleep, pain, and functional status. However, we are uncertain about the size of these covariations and, of particular interest, about potential time lags in covariation. Data and analyses conducted in this pilot study will allow us to refine hypothesis #2 for a definitive study.
Aim #5: Identify issues related to recruitment, subject retention and follow-up that will be important in planning a larger, more definitive study.
- Amishi Jha, PhD
- Asssistant Professor of Psychology, University of Pennsylvania
-
-
Development and Assessment of a Computerized Training Method to
Improve Sustained Attention and Reduce Mind Wandering
-
Difficulties sustaining attention to a task are common to individuals with a number of neurological and psychiatric disorders (Swaab-Barneveld, 2000), including traumatic brain injury (TBI; Whyte et al., 1995). This proposal describes a project for the development of a new computerized training method for improving disordered or suboptimal sustained attention in TBI patients and other clinical and sub-clinical populations. It is based on recent research on mind-wandering (Smallwood & Schooler, 2006), which is defined as task-irrelevant thought. We propose to utilize aspects of experimental paradigms previously used to assess mindwandering to develop a new computerized training protocol that we hypothesize will help trainees to improve their attentional focus during a reading task, with effects that may generalize to other tasks and situations. The key elements of this technique are that (a) the computer uses probe stimuli to detect mind-wandering and provide feedback to a participant to make them aware of the frequency of their attentional lapses, and (b) participants are trained to constantly monitor and report on their own attentional lapses, with feedback provided to a subject about deficient self-monitoring by comparing self-monitoring of attentional lapses to computer-monitored attentional lapses as detected with probe stimuli.
This approach has several important benefits. First, the training itself is superimposed on the reading of texts which could be selected for educational/occupational merit; the secondary educational/occupational benefits may help participants to adhere to the training regimen. This contrasts with other behavioral programs for the treatment of attention deficits that participants may not complete because of their tedious nature. Second, though we expect that the effects of this training regimen will result in improvements in sustained attention that will generalize to a variety of contexts, even if there is no such generalization, improvement in attention only during reading would itself an important accomplishment. Third, even if the training does not generalize beyond reading, the basic strategy of this method could be applied to other common and important situations, such as on-the-job training, listening to lectures, driving, and aviation.
- 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.