Cognitive Neuroscience Commons^™

Examining Metacognitive Access To Low-Level Ensemble Representations, Vladimir Mudragel

Dissertations, Theses, and Capstone Projects

Ensemble perception is a process that allows our sensory systems to rapidly extract summary information about the stimuli in the environment. For example, we are able to get a sense of the average number of items in a group of similar items (Burr & Ross, 2008; Halberda, Sires, & Feigenson, 2006) or the average size of a group of similar shapes of different sizes (Ariely, 2001). It is theorized that the qualitative result of ensemble perception is that it provides a gist impression of the current environment, which then enables attentional processes in the brain to determine which parts of …

Transcranial Direct Current Stimulation Studies Investigating The Role Of The Dlpfc In Memory And Metamemory, Casey M. Imperio

Dissertations, Theses, and Capstone Projects

Metamemory, broadly defined as knowledge about one’s own memory, is thought to consist of two separate processes, monitoring, the ability to assess the contents of your own memory, and control, altering behavior in service of memory, that work together to aide in encoding and retrieval processes. Prior work has shown that metamemory monitoring accuracy can be improved in a semantic memory task via high-definition transcranial direct current stimulation (HD-tDCS), a form of non-invasive brain stimulation, over the left dorsolateral prefrontal cortex (DLPFC). Over three experiments, the current dissertation sought to replicate and extend this work by: 1) testing the effects …

The Effects Of Music Therapy On Elderly Adults With Dementia, Jeante J. Jackson

Dissertations, Theses, and Capstone Projects

As people age, the brain is more susceptible to changes that diminish cognitive function. In recent years neuroscience has found convergent evidence between music therapy and brain architecture, as it has shown the generation of new connections in the brain or a reorganization and possible strengthening of existing connections already in the brain. However, the literature regarding music training’s effects on executive control, selective attention, and speech processing is lacking particularly when it comes to older populations.

This study investigated Verbal Working Memory, Visuospatial Attention and Task Initiation, and Auditory Selective Attention in a 91-year-old adult (B.P.) diagnosed with dementia. …

Into The Unknown: Exploring The Role Of Uncertainty In Threat-Safety Discrimination, Maia Kinney-Petrucha

Dissertations, Theses, and Capstone Projects

Learning to predict the arrival of threat is crucial to survival. Key to this learning process is the ability to discriminate between which stimuli signify safety and which signify threat. The extent to which a threat is uncertain impacts this ability, but which factors of uncertainty are primarily responsible remains unresolved. Uncertainty at the level of the stimulus can be examined in threat learning paradigms by adjusting threat reinforcement rate, referring to the frequency at which a cue is reinforced with an aversive stimulus. Previous research has shown that a continuous (more certain) threat reinforcement is associated with enhanced threat …

Analysis Of Electrophysiological Markers And Correlated Components Of Neural Responses To Discourse Coherence, Kurt M. Masiello

Dissertations, Theses, and Capstone Projects

Constructing meaning from spoken language is invaluable for learning, social interaction, and communication. In clinical populations with developmental disorders of speech comprehension, the severity of disruption can persist and vary from limiting occupational opportunities to lower performance outcomes. Previous research has reported an event-related potential (ERP) neural positivity over right hemisphere lateral anterior sites in response to semantic and discourse processing. Although useful as a marker for clinical populations of autism spectrum disorder (ASD) and developmental language disorder (DLD), little is understood about the dynamics and neural sources of this biological marker. In addition to traditional methods of ERP analysis, …

Development And Characterization Of A Novel, Genetically- Encoded Sensor To Image Sonic Hedgehog Signaling In Functional Circuits, Sonia Bernal

Dissertations, Theses, and Capstone Projects

Dynamic neurotransmitter and neuromodulator signaling in functional circuits is the neural substrate of animal behavior and cognition. The study of said circuits requires tools with sufficient spatiotemporal dynamics that can probe complex signaling patterns and decode their functional relevance by coupling the signal to behavioral output, ideally in awake, behaving animals. Much is known about the role of classical neurotransmitters such as dopamine in behavior, but a wide variety of peptides and small molecules also regulate neuronal transmission. One of these is Shh, whose presence has been observed in a variety of brain regions known to modulate movement, perception, and …

Clustered Protocadherins Ubiquitination And Phosphorylation Regulates Surface Expression, Albert Ptashnik

Dissertations, Theses, and Capstone Projects

Clustered protocadherins (Pcdhs) are a family of 60 adhesion-like molecules forming a neural barcode. In vertebrate neurons, 60 Pcdhs are coded by a large gene cluster. Numerous axons in the cluster are coding for the different extracellular, transmembrane, variable portion of the cytoplasmic and constant cytoplasmic domains where their expression is controlled epigenetically. These proteins mediate interactions between axons, dendrites, and glial cells during neural development. Yet, Pcdhs are not strictly adhesion molecules. In the amacrine cells of the retina, Pcdhs promote avoidance of the same cell dendrites, where in the cortex Pcdhs promote interactions between dendrites and astrocytes. In …

Unexpected Arousal Suppresses Memory And Metamemory Predictions During Associative Face-Name Recognition Task, Sameer Sabharwal-Siddiqi

Dissertations, Theses, and Capstone Projects

Successful recognition often depends on probabilistic estimation of memory-signal. Arousal has been shown to offset the influence of heuristic evidence on memory prediction. We conducted three experiments that tested whether arousal also suppresses predictions relevant to memory confidence. Experiments employed associative face-name memory tasks that included retrospective (Experiments 1 and 2) or concurrent (Experiment 3) judgements of confidence. During test, subjects were presented with a masked-affective face on a subset of trials. By timing the masked-affective face to precede a recognition judgement (Experiment 1), we replicated the finding that unexpected arousal offsets the influence of heuristic evidence on expectations of …

Novel Therapeutic Strategies For Alzheimer’S Disease: Prostaglandin D2 Signaling And Its Human Polymorphisms As Well As A Polypharmacological Approach, Charles H. Wallace

Dissertations, Theses, and Capstone Projects

Alzheimer’s disease (AD) is an age related neurodegenerative disease with pathology that includes amyloid plaques, neurofibrillary tangles and non-resolving neuroinflammation. Non-resolving neuroinflammation lasts the entire course of the disease and has deleterious effects and is often thought to accelerate AD pathology. Non-Steroidal Anti-inflammatory Drugs (NSAIDs) have commonly been used as therapeutics to treat pain, inflammation and vascular. NSAIDs work by altering the cyclooxygenase (COX) mediated biosynthesis of prostaglandins which are lipid mediators that have many physiological functions, for example nociception, inflammation and vasodilation. Epidemiological studies support the notion that NSAIDs could be used to treat AD. Yet, clinical trials using …

Competitive And Facilitative Interactions Between Pavlovian Cues In Human Associative Learning: A Behavioral And Neural Analysis, Fahd Alhazmi

Dissertations, Theses, and Capstone Projects

Learning to anticipate significant events accurately is a crucial element of survival for all species. The process by which animals acquire this knowledge has been a central question of psychological research. A fundamental assumption of many learning theories is that the predictive value assigned to cues is not simply determined by their probability of reinforcement but rather by their ability to compete with other cues present during learning. The assumption of cue competition has significantly contributed to the development of behavioral and neuroscience research for decades, as it has opened the door to new empirical and theoretical advances on the …

Investigating Steady State Visually Evoked Potentials As A Novel Biosignature For Anxiety-Related Attention Bias, Elizabeth R. Davis

Dissertations, Theses, and Capstone Projects

Anxiety-related attention bias (AB), a type of cognitive bias underlying the development and maintenance of anxiety disorders, is typically defined as exaggerated attention towards threat; however, some individuals also demonstrate AB away from threat and in some instances, no detectable AB at all. Debate about the reliability and validity of AB behavioral measures has prompted examination of additional assessment methods. Neurophysiological methods, such electroencephalography (EEG), have yielded encouraging early findings. The steady-state visually evoked potential (SSVEP), a measure of selective visual attention derived from EEG, holds promise as a biosignature for AB. Research documents heightened SSVEP power to emotionally salient …

Withdrawal From Voluntary Oral Methamphetamine Reveals Female Specific Susceptibilities To Behavioral Deficits And Neurochemical Perpetuators Of Neurotoxicity And Drug Seeking Behavior, Nicoletta K. Memos

Dissertations, Theses, and Capstone Projects

MA is a potent, highly addictive psychomotor stimulant known to produce neurotoxic effects on the brain leading to neurological impairments^1-6 characterized by neurodegeneration of dopaminergic fibers, cell bodies and pathways, as well as brain regions such as the hippocampus, frontal cortex, and midbrain^1,5.

In MA addiction, women are more vulnerable to the behavioral and cognitive effects of MA compared to men. Adult human literature reveals gender differences in usage patterns and women demonstrate increased vulnerability to the neurotoxic effects and health effects of MA use. Women begin drug use at an earlier age, escalate drug use quicker, …

The Impact Of Focused Attention And Opening Monitoring Meditation Styles On Attention, Jennifer Wheary

Dissertations, Theses, and Capstone Projects

Mindfulness meditation – often broken down into two distinct types, focused attention (FA) and open monitoring (OM) – has been associated with a range of affective and attentional benefits. Using an attentional blink (AB) paradigm that demonstrated improved attention for novice FA meditators, we explored whether novices who engaged in a single, brief bout of meditation exhibited any differences in alpha or theta power during meditation, and whether these differences were apparent by meditation type. In the AB paradigm, participants are asked to identify two targets, T1 and T2, which are separated by 200-500 ms. Our results showed no significant …

Testing An Overtraining Protocol For Fear Learning In Humans, Gordon M. Haskell

Dissertations, Theses, and Capstone Projects

Successful regulation of fear memories is a fundamental tenet to the exposure-based therapies often employed by mental health professionals for individuals with PTSD, phobias, and other anxiety disorders. Consequently, the efficacy of these treatment methodologies is largely dependent on the strength of the fear memory, as stronger memories are often characterized by an increased resistance to extinction and heightened fear recovery. However, there is little consensus within the scientific community regarding how to effectively maximize fear memory strength in human studies, and the literature exploring the impact of variability in acquisition parameters on memory strength is sparse. Here, we tested …

Genetic Circadian Mosaics And The Clock Network’S Contributions To Sleep, Lukasz Widziszewski

Dissertations, Theses, and Capstone Projects

Circadian rhythms are physiological and behavioral changes which follow a 24-hour cycle. Drosophila Melanogaster’s circadian clock neuronal network (CCNN) has been identified and several subpopulations have been characterized based on previous studies; the classifications of subpopulations of neurons within the CCNN are based on a return of anticipatory locomotor activity preceding the two daily light transitions (Lights on = dawn/Lights off = dusk). The neurons responsible for the return of anticipatory morning locomotor activity have been referred to as the M-cells, the group of neurons known to rescue evening anticipatory locomotor activity have been termed the E-cells. In this …

The Effects Of Near-Threshold Color Manipulation On Perceptual Decision-Making And Confidence Report, Trevor Caruso

Dissertations, Theses, and Capstone Projects

Confidence measures are sometimes used to index awareness below a participant’s criterion for what counts as being subjectively aware of a stimulus or stimulus property. If confidence ratings index awareness below subjective thresholds, then one might be tempted to use confidence ratings in place of subjective reports of whether a stimulus/stimulus property was “seen” or “unseen”. As such, a dissociation of confidence from performance may be construed as a dissociation of subjective awareness from objective task performance. This methodology has been used as supporting evidence for blindsight in typical observers (Balsdon and Azzopardi 2015; Peters and Lau 2015; Peters et …

Apathy And Brain Atrophy During The First Year Of Moderate-Severe Traumatic Brain Injury: A Longitudinal Study, Gulnaz Kudoiarova

Dissertations, Theses, and Capstone Projects

Apathy, defined as disinterest and loss of motivation, is a common complication after moderate-severe traumatic brain injury (msTBI). The existing body of research in various neurological and neurodegenerative disorders suggests that apathetic symptoms may be associated with variation in the volume of the brain regions such as dorsal anterior cingulate cortex and ventral striatum. However, the longitudinal pattern of TBI-induced atrophy in these key regions and its relationship with apathy symptoms remain to be demonstrated. The current study aimed to describe the atrophy pattern in the anterior cingulate gyrus (ACG) and the nucleus accumbens (NAc; part of ventral striatum) after …

A Randomized Controlled Trial Of Psychological Outcomes Of Mobile Guided Resonant Frequency Breathing In Young Adults With Elevated Stress During The Covid-19 Pandemic, Al Amira Safa Shehab

Dissertations, Theses, and Capstone Projects

Deep breathing practices have shown promise in reducing stress, anxiety, and depression in different populations, including young adults. Specifically, resonant frequency breathing can exert an impact on stress response systems through the vagus nerve and the hypothalamo-pituitary-adrenal (HPA) axis. This may induce reductions in stress and improvement in emotion regulation. Young adults, including college students, tend to be at a higher risk for psychological distress, as they face several psychosocial challenges. The COVID-19 pandemic has imposed new and unique stressors that resulted in higher levels of stress and emotional symptoms and it has been shown that this may have placed …

Working Memory Task Performance In Children With Sli: A Behavioral And Erp Study, Megan V. Mcveety

Dissertations, Theses, and Capstone Projects

In addition to language deficits, children with Specific Language Impairment often show deficits in tests of various aspects of working memory, including capacity, updating, and selective attention. The purpose of the present study is to examine the specific drivers of differences in working memory processing in 8–11 year-old children with and without SLI using behavioral and electrophysiological measures. Participants completed an n-back task with three working memory load conditions (0-back, 1-back, 2-back), with the addition of distractor trials at the 1-back and 2-back levels. The SLI group performed significantly less accurately across all task conditions. The children with SLI also …

Functional Connectivity Changes In The Default Mode Network In Moderate-To-Severe Traumatic Brain Injury, Emily J. Haight

Dissertations, Theses, and Capstone Projects

Traumatic brain injury (TBI) patients are known to have altered functional connectivity (FC), which has cognitive and behavioral significance and bears clinical implications. Previous literature has discovered a hyperconnectivity response to TBI, most notably in the default mode network (DMN). However, the exact pattern of changes in resting FC during the first year of recovery is unknown. We used resting-state functional magnetic resonance imaging to investigate longitudinal connectivity patterns in the DMN of 28 moderate-to-severe TBI patients as compared to 33 demographically matched healthy controls (HC). FC was assessed at 3, 6, and 12 months post-injury for patients using the …

The Effect Of Anticipatory Anxiety On Fear Extinction Learning, Daniela C. Echeverria

Dissertations, Theses, and Capstone Projects

Adaptive regulation of fear is dependent on successful fear extinction learning; therefore, investigating factors that both enhance and diminish fear extinction learning is a critical line of research. In the present study, we induce mild anticipatory anxiety during fear extinction learning in an attempt to modulate how participants extinguish fear memory. In the experiment, we apply a classic three-day fear learning protocol to both control participants (N = 20) and an experimental group (N = 20) with fear acquisition, fear extinction, and fear recovery phases; each phase is separated by a period of 24 hours and we use a skin …

Learning To Feel Safe: A Translational Study Of The Influence Of Safety Learning On Anxiety-Related Overgeneralized Fear, Hyein Cho

Dissertations, Theses, and Capstone Projects

Anxiety disorders are among the most common mental health diagnoses, affecting about a third of the population in their lifetime. However, approximately a third of individuals with anxiety do not respond to current treatment approaches, highlighting the need to identify additional potential therapeutic mechanisms. Safety learning is one such mechanism, but methodological challenges and a dearth of research have prevented the field from advancing the understanding of the role of safety learning in the etiology and remediation of anxiety disorders. Animal research, using single-cued safety learning paradigms, has yielded promising early findings, demonstrating that safety learning directly reduces anxiety-related behaviors …

Effects Of Working Memory Load On Ensemble Versus Individual Object Processing, Clark Moore

Dissertations, Theses, and Capstone Projects

Ensemble perception is the ability of the visual system to summarize object groups by their statistical properties. At a fundamental level, past studies show clearly that ensembles are perceived, and statistical information is sent to working memory such that a subject may report on the averages (Ariely, 2001; Brady and Alvarez, 2011). Studies show that subjects are capable of reporting ensemble statistics for large groups of objects with high accuracy, inferring that this process bypasses the capacity limitations of attention and working memory (Chong and Treisman, 2003; Baijal et al., 2013; Huang, 2015; Epstein and Emmanouil, 2017, 2021). However, few …

Using Fnirs To Identify Brain Regions Involved In Emotional Face Processing In Infants At High Risk For Autism Spectrum Disorder, Christian Martinez

Dissertations, Theses, and Capstone Projects

Faces provide an abundance of salient information, and within a few hours of being born, infants already show preferential attention to faces and face-like stimuli. Autism spectrum disorder (ASD) is a developmental disorder consisting of social communication and interaction difficulties, and individuals with ASD show differences in the behavioral and neural processing of faces. Prospective studies with infants at high risk for ASD (HRA; by virtue of an older sibling with ASD) have begun to look at whether responses to faces could be an early marker of later ASD. Using functional near-infrared spectroscopy (fNIRS), the current study measured oxygenated hemoglobin …

Examining The Transient Neural Dynamics Underlying Working Memory Maintenance For Complex Visual Stimuli, Chelsea Reichert Plaska

Dissertations, Theses, and Capstone Projects

Working memory (WM) is the temporary storage of information to accomplish a future goal. The WM delay period is the time after encoding but before retrieval when information is being maintained, typically in the absence of relevant stimuli. Understanding how the brain supports maintenance during the delay period, and how neural activity and connectivity are related to memory is critical for advancing both basic knowledge as well as informing declines in memory and cognition related to neurodegenerative diseases and healthy aging. An open question in the field of WM research is how information is stored during this delay period. One …

Influence Of Demographic, Clinical, And Neuroimaging Variables On Neuropsychological Recovery Trajectories After Moderate-To-Severe Traumatic Brain Injury, Elizabeth J. Leif

Dissertations, Theses, and Capstone Projects

Traumatic brain injury (TBI) is prevalent in people of all ages and all walks of life. Cognitive deficits are common after TBI and the recovery patterns are known to be variable across individuals. The current study investigates diffuse axonal injury (DAI), cerebral blood flow (CBF), and focal lesions, in addition to post-traumatic amnesia (PTA), as possible predictors of cognitive trajectory in moderate-to-severe TBI patients. Cognitive trajectory was evaluated with a battery of neuropsychological tests that were combined into three domains: processing speed, verbal learning, and executive function. Patients (N=44) were tested three times at 3, 6, and 12 months post-injury. …

Cognitive Changes Caused By Lps-Induced Neuroinflammation, Nancy De La Torre

Dissertations, Theses, and Capstone Projects

The brain performs cognitive processes finely orchestrated by timely precise action of neurons. Neurons functioning at their highest standard communicate with each other through perfectly functioning synapses. Microglia, as part of the immune system assist synaptic processing and have the ability to affect cognition. Indeed, microglia play a role in cognition. To investigate the link between microglia and cognition we utilized lipopolysaccharide (LPS) to pharmacologically activate microglia. LPS, normally present in the environment on the wall of Gram-negative bacteria is a pharmacological agent used to cause microglia activation in mice. LPS is a typical model to study changes induced by …

Caffeine Modulation Of Attention And Focus In Task Performance, Claudia R. Berger

Dissertations, Theses, and Capstone Projects

Caffeine has been a heavily researched drug for decades given its prevalence in global consumption, as well as its large impacts on metabolic and executive function research alike. The present study aims to combine a behavioral study (Experiment 1) with a feasibility study (Experiment 2) to test the impacts of variable caffeine consumption on task performance. For both studies, participants filled out a questionnaire regarding caffeine use. Experiment 1 examined whether caffeine modulated attention in an online behavioral task in which participants were asked to identify a target (e.g., female “ahpa”). Participants were tested twice once after consuming 12 ounces …

Sex/Gender Differences In Serial Position Profiles In Patients With Mild Cognitive Impairment And Healthy Controls, Emnet Z. Gammada

Dissertations, Theses, and Capstone Projects

Introduction: Alzheimer’s disease disproportionately affects more women, but paradoxically, men have a higher incidence of Mild Cognitive Impairment (MCI). Researchers have suggested that women’s verbal memory advantage across the lifespan reflects better premorbid skills, which then require more neurodegeneration to manifest early clinical impairment. To date, measurement of sex differences in verbal memory have used total list scores. We proposed that a granular examination of serial position effects (SPE) in list-learning can refine the source of sex/gender differences.

Methods: A cross-sectional analysis of participants with Mild Cognitive Impairment (MCI) and Healthy Controls (HC) was examined from the Alzheimer’s Disease Neuroimaging …

Structural And Functional Brain Markers Of Trauma-Related Symptoms, Glenn Blessington

Dissertations, Theses, and Capstone Projects

The neurocircuitry model of posttraumatic stress disorder suggests an association between trauma-related symptoms and abnormalities in the structure and function of limbic and prefrontal brain regions. Evidence also suggests that these structural and functional abnormalities are related. We tested the relation between whole brain white matter integrity, resting-state functional connectivity of a fronto-limbic network, and trauma-related symptoms in 22 trauma-exposed women. We hypothesized that components of whole brain white matter would correlate with components of resting connectivity within a fronto-limbic network. We used parallel independent component analysis (pICA) to test the associations between whole brain fractional anisotropy (FA) maps and …