Neuroscience Research //
Neuroscience Research at MRN
With MRN’s highly advanced tools and techniques, we have been able to expand the research scope beyond typical neuroimaging. A few of the specialized research areas include, oral orthotics, brain stimulation (TDCS), learning, memory, aging and research ethics. MRN’s imaging services, capabilities and expertise allow our investigators the freedom to pursue groundbreaking research ideas.
- Incidental findings in neuroimaging research. >
- Biomarkers for White Matter Injury in Mixed and Vascular Cognitive Impairment >
- COBRE >
- Project Raptor: Examining the Interplay between Resting Oscillations, Novelty Processing and Attention in PTSD >
- Cognitive Neuroscience of Reward >
- Cognitive and Psychiatric Functioning in Aging >
- Targeted Transcranial Direct Current Stimulation (tDCS) to Enhance Speech-Language Treatment Outcomes in Persons with Chronic Post-Stroke Aphasia >
Incidental findings in neuroimaging research.
Neuroimaging provides a tremendous amount of information to the researcher. It also uncovers findings in approximately a third of all research subjects that may not be related to the original research question, but may have medical relevance for the individual. Ethical principles need to be considered when deciding how much and by what method research information is offered directly back to subjects who volunteered for the research project. Our multidisciplinary collaborative group is studying the effect of providing research subjects with an official radiology reading of their MRI scan, probing relationships between key ethical principles such as beneficence, subject autonomy and justice. Our goal is to contribute to the national discussion regarding incidental findings in research, and demonstrate that findings of potential clinical significance can be returned in a way that minimizes harm and maximizes personal benefit for research participants.
Biomarkers for White Matter Injury in Mixed and Vascular Cognitive Impairment
Another fate that awaits most of us, as we enter the latter decades of our lives, is cognitive decline. Whether this is a normal loss of memory or cognitive “processing speed” that we learn to manage and live with or a more serious loss of cognitive function, as in Alzheimer’s disease or any of the many forms of vascular dementia, depends on factors that are not well understood at present.
The project Biomarkers for White Matter Injury in Mixed and Vascular Cognitive Impairment, led by Dr. Gary Rosenberg, is aimed at combining several clinical and neuroimaging measures to arrive at a better differential diagnosis of vascular dementia, to help guide the development of treatments, as well as to discover more about the underlying pathologies of the different forms of the disease. Early results from this project have been reported in Taheri et al., Blood-Brain Barrier Permeability Abnormalities in Vascular Cognitive Impairment, Stroke, 42(8):2158-63 (2011). A preliminary report of our neurochemical findings (Gasparovic et al., submitted, 2012) demonstrates that NAA and total creatine are more strongly related to cognitive function in subjects with vascular dementia than is ischemic lesion volume.
The current Phase III (P-III) COBRE project extends the Phase I and Phase II COBRE projects over the past 11 years. These successful projects have built up infrastructure and created a cutting edge brain imaging center. The Mind Research Network (MRN) houses an Elekta Neuromag 306-channel MEG System, a high density EEG lab, a 3T Siemens Trio MRI scanner, and two mobile 1.5T Siemens Avanto MRI scanners. Additional resources include a centralized neuroinformatics system, a strong IT management plan, and state-of-the-art image analysis expertise and tools. This Phase III COBRE continues this momentum and moves the technical cores we have developed into a position of long term sustainability. These include a multimodal data acquisition (MDA) core, algorithm and data analysis (ADA) core, and a biostatistics and neuro-informatics (BNI) core. These cores have begun to serve MRN and the greater community, as well as other institutions including extensive collaborations with IDeA funded projects in New Mexico and other states. The COBRE includes an extensive educational, mentoring, and faculty development program to carefully mentor and position faculty who use the cores to maximize their potential to successfully compete for external funding, thus fulfilling the ultimate goals of the COBRE program. This Phase III COBRE helps to sustain the Mind Research Network and New Mexico as one of the premier brain imaging sites.
Project Raptor: Examining the Interplay between Resting Oscillations, Novelty Processing and Attention in PTSD
Individuals with posttraumatic stress disorder (PTSD) self-report problems with attention, and consistent with such reports, neurocognitive studies find that PTSD is associated with impaired executive functioning including deficits in working memory and sustained attention. This exploratory study will use MEG to examine resting state networks and responses to target, standard, and novel Auditory Oddball stimuli to determine associations between responses and resting state and with attention performance in combat-exposed service members with posttraumatic stress disorder (PTSD) compared to a combat control group. Informed by prior event-related potentials studies, we will examine the underlying contributions of specific brain regions to the attentional process.
Cognitive Neuroscience of Reward
The electroencephalographic (EEG) response known as the Reward Positivity (RewP) is a promising candidate biomarker of diminished valuation in anhedonia. The RewP is only elicited by the presentation of a rewarding outcome and it scales with the central feature of reinforcement learning models, the positive reward prediction error (+RPE). Thus, the RewP is specific and sensitive to +RPE, fulfilling the stringent criteria of being an invariant neural marker of this computational process. Importantly, the RewP is boosted by appetitive states and is diminished in depressed individuals, indicating that emotional processes influence this marker of reward learning. While prior work has effectively described these correlations (e.g. Foti and Hajcak, 2009), we do not know how emotion (e.g. depression) and +RPE interact to influence valuation. The objective of this project is to test whether mood directly diminishes +RPE coding in the RewP, or if these are separable influences on this signal. The aim of this arm of the study is to determine if anhedonia and +RPE have independent or interactive influences on the source-level generators underlying the RewP.
Cognitive and Psychiatric Functioning in Aging
MRI biomarkers have been studied in individual neurodegenerative diseases, but there have been minimal amounts of research examining how MRI biomarkers relate to cognitive and psychiatric dysfunction accross neurodegenerative conditions. This study will examine, longitudinally and observationally, individuals diagnosed with neurodegenerative conditions and how those measures relate to cognitive and psychiatric functioning and whether those measures can predict functional outcomes over time. This research ultimately aims to facilitate earlier detection and improve treatments for neurodegenerative conditions. A significant gain in understanding the utility of MRI biomarkers to identify the presence and progression in neuropathological processes across neurodegenerative conditions is expected over the course of this study.
Targeted Transcranial Direct Current Stimulation (tDCS) to Enhance Speech-Language Treatment Outcomes in Persons with Chronic Post-Stroke Aphasia
After a brain injury, such as a stroke or traumatic brain injury, people may have problems speaking and/or understanding other people speaking. While language therapy for aphasia is effective, improvements are typically slow, and gains may be small. Non-invasive brain stimulation has been suggested as a method to enhance outcomes from language therapy with brain stimulation in people with aphasia. The specific aims will be investigated using randomized placebo-controlled clinical trial.