Neuroscience and Neurobiology Commons^™

Individual Differences In Structure Learning, Philip Newlin

Theses and Dissertations

Humans have a tendency to impute structure spontaneously even in simple learning tasks, however the way they approach structure learning can vary drastically. The present study sought to determine why individuals learn structure differently. One hypothesized explanation for differences in structure learning is individual differences in cognitive control. Cognitive control allows individuals to maintain representations of a task and may interact with reinforcement learning systems. It was expected that individual differences in propensity to apply cognitive control, which shares component processes with hierarchical reinforcement learning, may explain how individuals learn structure differently in a simple structure learning task. Results showed …

A Two-Layer Model Explains Higher-Order Feature Selectivity Of V2 Neurons, Timothy D. Oleskiw, Justin D. Lieber, J. Anthony Movshon, Eero P. Simoncelli

MODVIS Workshop

Neurons in cortical area V2 respond selectively to higher-order visual features, such as the quasi-periodic structure of natural texture. However, a functional account of how V2 neurons build selectivity for complex natural image features from their inputs – V1 neurons locally tuned for orientation and spatial frequency – remains elusive.

We made single-unit recordings in area V2 in two fixating rhesus macaques. We presented stimuli composed of multiple superimposed grating patches that localize contrast energy in space, orientation, and scale. V2 activity is modeled via a two-layer linear-nonlinear network, optimized to use a sparse combination of V1-like outputs to account …

A Bayesian Account Of Depth From Shadow, James Elder, Patrick Cavanagh, Roberto Casati

MODVIS Workshop

When an object casts a shadow on a background surface, the offset of the shadow can be a compelling cue to the relative depth between the object and the background (e.g., Kersten et al 1996, Fig. 1). Cavanagh et al (2021) found that, at least for small shadow offsets, perceived depth scales almost linearly with shadow offset. Here we ask whether this finding can be understood quantitatively in terms of Bayesian decision theory.

Estimating relative depth from shadow offset is complicated by the fact that the shadow offset is co-determined by the slant of the light source relative to the …

Fixational Eye Movements, Perceptual Filling-In, And Perceptual Fading Of Grayscale Images, Michael E. Rudd

MODVIS Workshop

No abstract provided.

Constraining Computational Models Of Brightness Perception: What’S The Right Psychophysical Data?, Guillermo Aguilar, Joris Vincent, Marianne Maertens

MODVIS Workshop

No abstract provided.

Identifying And Localizing Multiple Objects Using Artificial Ventral And Dorsal Visual Cortical Pathways, Zhixian Han, Anne Sereno

MODVIS Workshop

We concluded in our previous study that model cortical visual pathways actively retained information differently according to the different goals of the training tasks. One limitation of our study was that there was only one object in each input image whereas in reality there may be multiple objects in a scene. In our current study, we try to find a brain-like algorithm that can recognize and localize multiple objects.

Model Of Visual Contrast Gain Control And Pattern And Noise Masking, Joshua A. Solomon

MODVIS Workshop

The first stage of the model can be subdivided into a global contrast sensitivity function (a 2-D log-parabolic filter of spatial frequency), followed by an array of sensors having Gabor-pattern receptive fields. The second stage is contrast gain control. At this stage, sensor outputs are subjected to an expansive transformation. Then the outputs are pooled and used to inhibit (or “normalize”) each other. Inhibition is strongest between sensors with similar preferences for orientation, spatial frequency and spatial location. In the final stage of the model, the nomalized sensor outputs for each image are subjected to Minkowski pooling. Two-alternative, forced-choice detection …

Trauma Healing With The Neurosequential Model Of Therapy And Bal-A-Vis-X, Becky Johnston

Educational Specialist, 2020-current

Stigma related to childhood trauma is shifting with the help of advancements in the understanding of neurobiology and interventions that are proving to be effective for healing. There are immense costs and consequences for survivors of childhood trauma and their loved ones that were not so long ago considered irrelevant and the notion that kids bounce back from adversity was previously popular in the psychological community (Perry & Szalavitz, 2017). The broad strokes of Dr. Bruce Perry’s clinical intervention model, The Neurosequential Model of Therapy (NMT) describes a trauma-sensitive, sequential approach to changing the stress response within mental health counseling. …

The Effects Of Astrocytic Derived Insulin-Like Growth Factor (Igf-1) On Cognition And Astrocytes, Destiny Wilson

Honors Theses

Insulin-like growth factor 1 (IGF-1) is a neuroendocrine signaling hormone that plays a vital role in growth and development, as well as learning and memory. Inhibition of this hormone results in cognitive impairments like those seen with age-related decline. While a majority of research has focused on the role of IGF-1 on neurons, the role of astrocytes still needs to be explored. Our research investigates how astrocytes and cognition are affected as a result of direct regulation of localized IGF-1 production in early development and after puberty. Preliminary studies in our laboratory established a connection between IGF-1 and glial fibrillary …

Investigating The Neuroprotective Effects Of Cannabinoids And Insulin-Like Growth Factors On Glia With Induced Inflammation, Caleb Bloodworth

Honors Theses

Chronic inflammation is a driver of numerous neurodegenerative diseases that reduce quality of life for affected individuals. Non-psychoactive cannabinoids have begun to gain more interest in the world of anti-inflammatory medicine for chronically ill patients. Along with these cannabinoids, insulin-like growth factor-1 has been examined for its association with downregulation of inflammation. Our research aimed to investigate how neuroglia are affected by treatment with cannabinoids or IGF-1 in the face of inflammation from HIV-1 protein, Tat, or lipopolysaccharide (LPS). Preliminary studies in our laboratory showed that neither cannabinoids or IGF-1 treatment altered astrocyte morphology or overall astrocyte viability under baseline …

The Effects Of Acute Exercise Intensity On Retrieval-Induced Forgetting, Geoffrey Reliquias

Honors Theses

Previous research has indicated that aspects of cognitive inhibition may be enhanced after engaging in acute exercise. Notably, cognitive inhibition has been theorized as a potential mechanism for a form of active forgetting known as retrieval-induced forgetting (RIF). Given that cognitive inhibition may explain the RIF phenomenon, and is also influenced by exercise, it is plausible that acute exercise may directly influence RIF. To our knowledge, only one study has examined whether acute exercise has an effect on RIF. The findings of that study did not find a statistically significant effect for RIF; however, we believe that the rather small …

Frailty And Neurocognition In Prostate Cancer, Lindsey Hanson

Theses & Dissertations

Prostate cancer (PCa) treatment often leads to distressing side effects ranging from muscle loss, physical inactivity, and fatigue to cancer associated cognitive decline (CACD). Evidence suggests that men treated with androgen deprivation therapy (ADT) may have a specifically high risk of CACD, partially due to increased frailty. However, the current literature on cognitive effects of ADT is equivocal. Therefore, the primary objectives of this study were to (1) compare cognitive function, physical activity (PA), and fitness in men receiving ADT, men scheduled to receive radiation, and men under active surveillance for PCa; (2) examine changes in cognitive performance and PA …

Astrocytic Contribution To Sensory Hypersensitivity In A Mouse Model Of Fragile X Syndrome, Lara E. Bergdolt

Theses & Dissertations

Fragile X syndrome (FXS) is the most common form of inherited intellectual disability and a leading cause of autism spectrum disorder (ASD). FXS is caused by mutations in the fragile X mental retardation gene (FMR1), which result in complete or substantial loss of expression of its protein product fragile X mental retardation protein (FMRP). Neuronal impairments in the absence of FMRP have been extensively characterized. However, much less is known about the impact that loss of FMRP has on the physiology and function of astrocytes and the implications for behavior. A common behavior exhibited by both FXS and ASD patients …

Linking Spinal Cord Circuits With Upper Limb Sensorimotor Control In Adults With Cerebral Palsy, Saihari Dukkipati

Theses & Dissertations

Cerebral palsy (CP) is the most common neurological disorder originating in childhood, but most of the people living with CP are currently adults. While people with CP continue to get older, the amount of research focused on adults has been rather limited. The early childhood insults leading to CP are thought to originate in the brain, but the effects on the entire neuromuscular system across the lifespan have only recently started to be explored. Of note, recent neuroimaging evidence suggests that the cervical spinal cord structure is atypical in adults with CP. However, it is largely unclear how the neurophysiological …

Effects Of Music Exposure On Autobiographical Memory In Alzheimer's Patients: A Systematic Review And Meta-Analysis, Gregory Vance

Honors Theses

The progression of Alzheimer’s disease is primarily characterized by a loss of memory concerning past events, as well as a lack in ability to create new memories. While this spans across many subsets of memory, such as recognition, recall, and autobiographical memory, there seems to be a lesser impact on musical memory in those with Alzheimer’s. Multiple studies have suggested that exposure to music and introduction of music therapy can even improve other aspects of memory in Alzheimer’s patients. This systematic review and meta-analysis sought to examine the relationship between music exposure and autobiographical memory specifically. A pool of electronic …

Effects Of Acute Exercise Intensity On Behavioral Pattern Separation, Sarah Amitin

Honors Theses

Prior work has demonstrated that acute exercise can improve memory performance. Less research, however, has determined whether this beneficial effect occurs through exercise reducing the influence of related or interfering stimuli. Thus, the present experiment evaluated if acute exercise can improve memory by reducing the interference of similar or conflicting information. A mnemonic similarity task was used where participants studied pictures of a wide variety of objects. The retrieval portion of the task displayed a set of objects in which they had to identify as old (already studied), new, or similar. The list of objects in the retrieval phase had …

Innate Immunity In The Pathobiology And Treatment Of Infectious And Neurodegenerative Diseases, Mai Mostafa

Theses & Dissertations

Mononuclear phagocytes (MPs; monocytes, macrophages, and dendritic cells) are the governors of innate immunity which is the body’s first line of defense against microbial pathogens. They act beneficial or detrimental. They are crucial for an effective non-specific immune response to invading pathogens by engulfing, destroying, then eliciting an adaptive specific immune response. Given their pivotal functions in the host immune defense, studying MP immune responses in disease is paramount important for understanding disease pathobiology and uncovering therapeutic strategies.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the driver of acute respiratory distress syndrome (ARDS) in coronavirus disease 2019 (COVID-19) amongst …

A Preliminary Report: The Hippocampus And Surrounding Temporal Cortex Of Patients With Schizophrenia Have Impaired Blood-Brain Barrier, Eric L. Goldwaser, Randel L. Swanson, Edgardo J. Arroyo, Venkat Venkataraman, Mary C. Kosciuk, Robert G. Nagele, L. Elliot Hong, Nimish K. Acharya

Rowan-Virtua Research Day

Schizophrenia (SZ) is one of the most severe forms of mental illness, yet mechanisms remain unclear. A widely established brain finding in SZ is hippocampal atrophy, and a coherent explanation similarly is lacking. Epidemiological evidence suggests increased cerebrovascular and cardiovascular complications in SZ independent of lifestyle and medication, pointing to disease-specific pathology. Endothelial cell contributions to blood-brain barrier (BBB) compromise may influence neurovascular unit and peripheral vascular function, and we hypothesize that downstream functional and structural abnormalities may be explained by impaired BBB.

Examining Levels Of Catecholamine Neurotransmitter Regulatory Proteins Within The Prefrontal Cortex Of Rodents Following Traumatic Brain Injury, Eleni Papadopoulos, Christopher P. Knapp, Claire M. Corbett, Jessica Loweth, Rachel L. Navarra

Rowan-Virtua Research Day

Traumatic brain injury (TBI) resulting from impact to the head can cause long lasting impairments of cognitive processes that lead to increased risk-taking behavior in clinical populations. Our laboratory has recently shown that female, but not age-matched male, rats increase preference for risky choices after multiple experimentally-induced mild TBI’s. Our overarching goal is to understand the neural mechanisms underlying TBI-induced increases in risk-taking behavior.

The prefrontal cortex (PFC) plays a prominent role in risk-based decision making. Sub[1]regions of the PFC include the medial PFC (mPFC), the orbitofrontal cortex (OFC), and the anterior cingulate cortex (ACC), and these sub[1]regions play specific …

Morphine-Induced Hyperactivity Is Attenuated By Intra-Accumbens Administration Of The Highly-Selective Dopamine D3 Receptor Antagonist Vk4-40, Mansi Patel, Desta M. Pulley, Daniel Manvich

Rowan-Virtua Research Day

Opioids exert their abuse-related effects by enhancing dopamine (DA) neurotransmission within the brain’s mesolimbic reward system, a neural projection involving DA neurons in the ventral tegmental area (VTA) that project to medium spiny neurons within the nucleus accumbens (NAc). Mu (MOR) are expressed by several populations of GABAergic neurons that tonically inhibit VTA DA neurons. By inhibiting these GABAergic neurons in a MOR-dependent manner, opioids indirectly enhance DA neurotransmission via disinhibition of DAergic neurons. Accumulating evidence indicates that selective pharmacological antagonism of the dopamine D3 receptor (D3R) attenuates the abuse-related effects of several opioids, but the neurobiological mechanisms mediating this …