Medicine and Health Sciences Commons^™

Multimodal Neuroimaging Of Hiv And Aging, Brandon Lew

Theses & Dissertations

HIV infection remains a significant contributor to disease burden, and with the success of antiretroviral therapies, the population of people with HIV is aging. A growing literature suggests a relationship between HIV-infection and a profile of age advancement, most notably in molecular studies of epigenetics. However, despite the widely-known high prevalence of HIV-related brain atrophy, functional deficits, and HIV-associated neurocognitive disorder (HAND), epigenetic age advancement has not been linked to HIV-related changes in neuroimaging metrics.

We applied three neuroimaging methods, structural MRI, resting state functional MRI, and resting state MEG, to study the brain structure and function of 121 virally-suppressed …

Evaluating Anesthetic Protocols For Non-Human Primate Functional Neuroimaging, Megha Verma

Electronic Thesis and Dissertation Repository

Functional magnetic resonance imaging (fMRI) is a non-invasive technique that can be used to measure a proxy of neural activity in vivo with high spatial specificity. One subject can be followed for a long period of time to assess changes in functional brain organization. However, fMRI is extremely sensitive to motion. The challenges of training non-human primates to reduce motion in an MRI scanner motivate the study of anesthesia which is commonly used to substitute for this training. In this thesis, I compare three different commonly used anesthetic protocols: isoflurane, propofol-fentanyl in combination, and fentanyl alone, to test which of …

Maternal Hpa Axis Function During Parenting Is Associated With Reduced Brain Activation To Infant Cry And More Intrusive Parenting Behavior, Andrew Erhart

Electronic Theses and Dissertations

Previous research indicated that maternal cortisol function and maternal brain response to infant stimuli are separately related to differences in parenting behavior. Evidence from animal models have demonstrated that chronically high cortisol concentration alters brain structure and function, suggesting that studying these two mechanisms together may further improve understanding of parental behavior in human mothers. First time mothers of infants aged 1-7 months old (M age = 3 months) were recruited to participate. Mother’s cortisol concentration was measured during a naturalistic interaction with their infant and their behavior was coded for maternal sensitivity and nonintrusiveness. In a separate session using …

Inference Of Language Functional Network In Healthy, Cancerous And Bilingual Brains By Fmri And Network Modeling, Qiongge Li

Dissertations, Theses, and Capstone Projects

We study the underlying mechanism by which language processing occurs in the human brain using inference methods on functional magnetic resonance imaging data. The data analyzed stems from several cohorts of subjects; a monolingual group, a bilingual group, a healthy control group and one diseased case. We applied a complex statistical inference pipeline to determine the network structure of brain components involved with language. This healthy network reveals a fully connected triangular relationship between the pre-Supplementary Motor Area (pre-SMA), the Broca's Area (BA), and the ventral Pre-Motor Area (PreMA) in the left hemisphere. This "triangle'' shows consistently in all the …

Characterizing The Development Of Episodic Memory And Assessing The Reliability Of Fmri Measures, Lingfei Tang

Wayne State University Dissertations

The ability to remember past events is critical for everyday life and showed robust improvement over development from childhood to adulthood. With advances in noninvasive neuroimaging methods such as functional MRI in recent years, research efforts have been focused on identifying neural correlates underpinning developmental gains in memory performance. In my dissertation work, using a widely-validated subsequent memory paradigm, I aim to characterize functional MRI correlates of memory development. Specifically, I focused my investigation on identifying age differences in the functional patterns of two brain regions critical for memory, the prefrontal cortex and the hippocampus. Focusing on the prefrontal cortex …

The Semantic Memory Imaging In Late Life Pilot Study, Michael Adam Sugarman

Wayne State University Dissertations

Introduction: Several functional magnetic resonance imaging (fMRI) studies have analyzed the famous name discrimination task (FNDT), an uncontrolled semantic memory probe requiring discrimination between famous and unfamiliar individuals. Completion of this simple task recruits a semantic memory network that has shown utility in determining risk for Alzheimer's disease (AD). Specific semantic memory probes using biographical information associated with famous individuals may build on previous findings and yield superior information regarding risk for AD.

Method: Sixteen cognitively intact elders completed the FNDT and two novel tasks during fMRI: Categories (matching famous individuals to occupational categories) and Attributes (matching famous individuals to …

Neural Alterations Influencing Skilled Reading In Adhd: A Task-Based Fmri Study, Brianne Mohl

Wayne State University Dissertations

Attention-Deficit/Hyperactivity Disorder (ADHD) is a heterogeneous, neurodevelopmental disorder which co-occurs often with Reading Disability (RD). ADHD with and without RD consistently have higher inattentive ratings compared with typically developing controls, with co-occurring ADHD and RD (ADHD/+RD) also demonstrating impaired phonological processing. Accordingly, inattention has been associated with greater phonological impairment, though neither the neural correlates of the co-occurring disorders nor the association are well understood from a functional neuroimaging perspective. The goal was to assess to what extent ADHD/+RD differ from ADHD without RD (ADHD/-RD) and typically developing controls (TDC) in functional activation of attention- and reading-related areas during various …

Inhibitory Control Efficiency In Successful Weight Loss Participants, Kathryn Curran Olds

Graduate College Dissertations and Theses

Eating unhealthy foods and eating past satiety are inappropriate behaviors that promote obesity. The ability to effectively inhibit an inappropriate behavior is a key component of cognitive restraint and its impairment has been previously linked to obesity. In this study, a Go/No-Go fMRI task was completed by a cohort of adult women that had experienced initial weight loss followed by various levels of weight regain or continued weight loss. Region of interest fMRI analysis revealed that greater total weight loss was significantly related to decreasing activation in the right inferior frontal gyrus and the right superior frontal gyrus. These results …

Neural Correlates Of Episodic Memory Formation In Children And Adults, Lingfei Tang

Wayne State University Theses

The medial temporal lobe (MTL) and prefrontal cortex (PFC) are two key brain regions that support episodic memory formation in both children and adults, but the functional developmental of these regions remains unclear. In this study, we investigated the development of neural correlates of episodic memory formation using functional MRI with a subsequent memory paradigm, administered to a cross-sectional sample of 83 children and adults. We found that MTL subregions showed an age-related increase in activation supporting memory formation of complex scenes. In addition, a functionally defined scene-sensitive region in the posterior MTL also showed similar increase and predicted better …

Network Dynamics Of Visual Naming, Christopher R. Conner

Dissertations & Theses (Open Access)

Recognition and naming of objects and actions are fundamental components of language. They involve several different systems working in coordination to accomplish a complex behavior. During visual naming, sensory and semantic processing are carried out by dedicated cortical substrates in the temporal and occipital lobes, while response selection and articulatory planning are handled by prefrontal cortex. Despite decades of research using lesion analysis, functional MRI and electro-encephalography, the precise dynamics involved remain unknown due to the inadequate spatio-temporal resolution of these methodologies. Of particular interest is the organization of semantic knowledge and the degree of serial and parallel organization of …

The Effects Of Mindfulness Meditation On Rumination In Depressed People, Rachel A. Sluder

Honors Theses and Capstones

Mindfulness meditation is a practice of focus, awareness, and non-judgmental acceptance of one's thoughts (Deyo et al., 2009; Kenny et al., 2007). Rumination is a maladaptive pattern of thought that is common in people with depression and other mood disorders. It can lead to further episodes of depression, and can be very destructive in that way (Nolen-Hoeksema, 2008). This paper reviews several studies on mindfulness meditation, depression, and rumination, with a focus on certain areas and phenomena such as alpha asymmetry (Keune et al 2013) and gamma band activity (Berkovich-Ohana et al., 2012). Modalities such as fMRI and EEG are …

The Influence Of Gender And Aging On The Neural Circuitry Supporing Facial Emotion Processing In Adults With Major Depressive Disorder, Emily Briceno

Wayne State University Dissertations

Major Depressive Disorder (MDD) is associated with decrements in facial emotion processing (FEP). Previous studies investigating the neural substrates of these decrements have often reported hyperactivity of emotion processing circuitry. Neural circuitry supporting FEP has been shown to be different between healthy men and women, and between young and elder adults. However, no prior studies have investigated how gender and aging affect emotion processing circuitry in individuals with MDD. The present study aimed to investigate the influence of gender and aging on emotion processing circuitry in MDD. One hundred-ten adults, grouped into subgroups according to MDD status, gender, and age …

Investigation Of Spatio-Temporal Effects Of Fmri Visual Field Mapping Techniques On V1, John J. Janik

Dissertations (1934 -)

Blood oxygenation level dependent functional magnetic resonance imaging has been used extensively for mapping the representation of the visual field within the human brain. Visual field mapping using fMRI has been used clinically to assess patients with cortical pathology and to plan surgical treatment impacting the visual system. The accuracy of fMRI-based visual field mapping methods needs to be better understood for clinical use. This accuracy can be important for presurgical mapping of brain function near a tumor resection site since inaccurate rendition of the underlying neural function could lead to inappropriate resection of viable brain tissue. The most widely …

Decoding Motor Intentions From Human Brain Activity, Jason P. Gallivan

Electronic Thesis and Dissertation Repository

“You read my mind.” Although this simple everyday expression implies ‘knowledge or understanding’ of another’s thinking, true ‘mind-reading’ capabilities implicitly seem constrained to the domains of Hollywood and science-fiction. In the field of sensorimotor neuroscience, however, significant progress in this area has come from mapping characteristic changes in brain activity that occur prior to an action being initiated. For instance, invasive neural recordings in non-human primates have significantly increased our understanding of how highly cognitive and abstract processes like intentions and decisions are represented in the brain by showing that it is possible to decode or ‘predict’ upcoming sensorimotor …