Cognitive Neuroscience Commons^™

Visual Imagery Subcategories And Their Neural Associations, Miguel Ibarguren

Undergraduate Scholarship and Creative Works

This literature review compiles research findings related to the brain areas associated with various visual imagery subcategories and explores their contributions to them. Through a search procedure, four research projects were used to identify ten distinct brain areas that demonstrated greater involvement in visual imagery. The visual imagery subcategories discussed in these research projects, and investigated in this review, include scene construction, episodic memory, imagery vividness, and visuospatial imagery. Scene construction was found to utilize the parahippocampal gyrus, hippocampus, retrosplenial cortex, and posterior parietal cortex. Episodic memory involves the same areas as scene construction, but also includes the precuneus and …

Cerebrospinal Fluid Biomarkers Not Associated With Neurologic Compromise Among Mild Cognitively Impaired Reverters With Parkinson's Disease, Cameron Ryczek

Electronic Theses, Projects, and Dissertations

Parkinson's Disease (PD) is a neurodegenerative disease characterized by motor (e.g. tremors) and non-motor symptoms (e.g. cognitive impairment). PD patients' change in cognitive functioning can be observed using the following classifications: cognitively intact, mild cognitive impairment (MCI), or dementia (PDD). MCI has many subtypes, one of which is MCI reversion which is defined as those with MCI at one time point reverting to cognitively intact later. While there is limited research into the utility of MCI reversion and its relationship with cerebrospinal fluid (CSF) biomarkers in PD, this study will begin to elucidate this relationship. To this end, data from …

Affective Liking Influences Reward Processing In Depression: A Computational Eeg Approach, Garima Singh

Psychology ETDs

Reinforcement learning (RL) enables agents to learn through interaction with their environment. This empowers individuals to optimize actions in complex and dynamic settings. The component of event related potential (ERP) termed as the Reward Positivity (RewP) evidently signifies a fundamental reward prediction error (RPE) associated with rewards. This characteristic implies that it represents a fundamental computational process in the assessment of RL. When a reward is particularly pleasurable or liked by an individual, it tends to elicit an amplified RewP signal, reflecting the heightened positive affect. RPE arises from disparities between anticipated and actual rewarding outcomes and is known to …

Sex Differences In Stress Reactivity, Brain Morphology, And Oxytocin In The Hypothalamus Of The Gray Short-Tailed Opossum (Monodelphis Domestica), Esperanza I. Zacarias, Daniela Rodriguez, Alexandra Chalons, Sasawan Heingraj, Nicole Altamirano, Joseph Rafac, John L. Vandeberg, Mario Gil

Research Colloquium

Understanding the effects of stress on behavior and cognition is important due to its impact on mental health and wellbeing (Schneiderman et al. 2005). Translational animal research can contribute to the development of new treatments that can improve therapeutic outcomes and our understanding of the neurobiology of stress. In the present study, we complement behavioral stress reactivity with immunohistochemical localization of oxytocin in the hypothalamus, a neuropeptide that regulates stress (Neumann & Slattery, 2016). Oxytocin has potential therapeutic use for mental health disorders (Neumann & Slattery, 2016), and the effects of oxytocin seem to be sexually dimorphic (Love, 2018). Using …

Understanding The Resources, Barriers, Facilitators And Interests About Aging And Dementia Research Of Community Members From The Rio Grande Valley, Karla Daniela Lopez Lorenzo, Rosa V. Pirela Mavarez, Gabriela Osuna, Kendra Stine, Nathalie Chacon, Noe Garza, Gladys E. Maestre

Research Symposium

Background: One of ten people aged 65 develops Alzheimer’s Disease and it is one of the sixth-leading cause of death in the United States. The Rio Grande Valley (RGV) is mostly constituted by Hispanic/Latinos (93%), a population that has a 1.5X increased risk of AD onset. Nevertheless, there are not enough resources to support people living with dementia and their care partners. This study will leverage research efforts deployed by the RGV Alzheimer’s Disease Resource Center for Minority Aging Research to understand the social representations about the resources, barriers, facilitators, and interests of the RGV community about dementia and Alzheimer’s …

The Neural Sequalae Of Subjectively Experiencing Autobiographical Memories From The Remote Past And Recent Present Using Fmri, Ava G. Peruski, Nim Singh, Brendan E. Depue

The Cardinal Edge

Autobiographical memory is central to one's sense of self and continuity from past to present. Despite this, there is little research on the neural correlates underlying individual subjective experience of autobiographical memory and how that is related to brain phenomena (i.e., activity, communication). The purpose of this study was to help minimize this gap. We recruited twenty healthy adult participants, who were asked to generate memory cues (1-3 word descriptions) for locations and objects from their early and recent life. After 24 hours, participants were shown these cues then asked to recall the appropriate memory while in an fMRI scanner. …

Attenuated Typicality Effect In Category-Based Inferences: Implications For Autism Spectrum Disorder, Janani Rajagopalan

Dissertations, Theses, and Capstone Projects

Individuals diagnosed with Autism Spectrum Disorder (ASD) often encounter challenges in assimilating atypical exemplars into their categorical prototypes, a cognitive hurdle that can impact their interpretative and integrative capacities. Addressing this problem, the present research sought to develop a robust methodological approach to reduce the effect of this disparity. We examined the elements embedded within the category's internal structure, with the intention of experimentally attenuating the pronounced typicality effect, which is often exaggerated in ASD.

Across four experiments, the thesis investigated the cognitive and neural underpinnings that shape the access to the typicality gradient intrinsic to a category's structure. The …

Automatic Analysis Of The Frequency, Vigor, And Complexity Of Spontaneous Locomotion Bouts Of Mice With Loss And Gain Of Function Of The G Protein-Coupled Receptor Smoothened In Cholinergic Neurons, Aleksandra Feshchenko

Dissertations, Theses, and Capstone Projects

Locomotion, a fundamental behavior, is classically assessed using simple metrics of velocity and total distance moved in an open field. This behavior however offers rich data about the organization and breadth of actions an animal can take while only facing limitations due to the bio-mechanical constraints of the organism. Importantly, these actions are not biased towards a particular task-solution space imposed by many behavioral paradigms. Here, to analyze motor complexity in freely ambulating mice, we developed a method for the automatic and unbiased identification of locomotor bouts which we call Bout Finder (BF). This analysis utilizes Open Feld data to …

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 …

Brainwaves, Memory, And Reward, Rebecca Mccune

Dissertations, Theses, and Capstone Projects

The development of effective educational curricula for enhancing learning involves the crucial consideration of effort and rewards. In the realm of education, teachers commonly employ rewards as motivational tools. Traditionally, these rewards are given to students as a recognition of their successful performance. However, a thought-provoking idea emerges: What if we were to extend rewards to students not solely based on accurate answers, but also on the effort they invest, even in cases where their actual response might be incorrect? Our study explores the potential impact of this approach on the way information is absorbed and subsequently retained, specifically focusing …

The Directional Effect Of Target Position On Spatial Selective Auditory Attention, Heesung Park

Dissertations, 2020-current

Spatial selective auditory attention plays a crucial role in listening in a mixture of competing speech sounds. Previous neuroimaging studies have reported alpha band neural activity modulated by auditory attention, along with the alpha lateralization corresponding to attentional focus. A greater cortical representation of the attended speech envelope compared to the ignored speech envelope was also found, a phenomenon known as 'neural speech tracking’. However, little is known about the neural activities when attentional focus is directed on speech sounds from behind the listener, even though understanding speech from behind is a common and essential aspect of daily life. The …

Voluntary Action And Conscious Intention, Jake Gavenas

Computational and Data Sciences (PhD) Dissertations

Traditional experimental methodology in neuroscience involves comparing responses to different stimuli to make inferences about the human brain. However, human volition entails making decisions and acting in a manner that is underdetermined by the external environment. Investigations of the neuronal basis of volition have led to new controversies regarding the existence of free will, and offer potential directions for medical treatments of disorders such as addiction, akinetic mutism, and locked-in syndrome. However, because volition experiments leave aspects of responses “up to” participants, neuroscientists must utilize computational techniques such as modeling, simulation, and advanced analyses to progress our understanding of human …

Unraveling The Neural Basis Of Emotions: Advancing Understanding With Ecologically Valid Paradigms And High-Resolution Intracranial Eeg, Tiankang Xie

Dartmouth College Ph.D Dissertations

Background

Emotion arises from integrating information about the external world with memories of past experiences, current homeostatic states, and future goals. They play a vital role in regulating our thoughts, feelings and behaviors, significantly impacting our mental health. Thus, it is important to understand the neurobiological mechanisms that give rise to emotions. While there has been considerable work investigating the neural basis of emotions, progress has been hampered by several methodological limitations. For example, prior work has relied on relatively simple and isolated stimuli, which often fail to effectively capture the dynamic and multifaceted nature of emotional experiences in real-life …

Attention Visual, Baris Dingil

College of Computing and Digital Media Dissertations

This research presents an innovative approach to improving visual-spatial attention using a research tool based on the web. Recognizing the significant role visual-spatial attention plays in everyday life and cognitive function for humans, this research was undertaken with the aim of developing a user-friendly, accessible web-based tool called Attention Visual (attentionvisual.com) to enhance this crucial cognitive skill. This tool also facilitates data collection, potentially accelerating the pace and enhancing the quality of related research. Both qualitative and quantitative methods were utilized for data collection and analysis. In order to stimulate improvements in visual-spatial attention, the tool’s algorithm was structured to …

Limits To Sentience, Donald M. Broom

Animal Sentience

There are many parallels between cellular function in animals and plants. Plants can have complex interactions with their environments. But they lack a central nervous system, which is a prerequisite for sentience (the capacity to feel). In my view the suggestion that plants are sentient is not only empirically incorrect but potentially harmful to the efforts to protect the welfare of sentient beings.

Identifying A Neural Signature That Predicts Self-Focus, Danika Jean Geisler

Dartmouth College Master’s Theses

BACKGROUND AND AIM: People are remarkably self-focused, choosing to think and talk about themselves at disproportionately high levels. When people are instructed to think about the self in a task, activation occurs in the core subsystem of the default network, in particular the medial prefrontal cortex (MPFC). We hypothesize this tendency to “default back” to the core subsystem and MPFC as soon as we have a mental break sets our self-focus in motion. PROCEDURE: Participants completed a three-phase scanning session. In phase 1, they completed a resting state scan in which they intermittently answered questions about their thoughts. In phase …

An Erp Measure Of Non-Conscious Memory Reveals Dissociable Implicit Processes In Human Recognition Using An Open-Source Automated Analytic Pipeline, Richard J. Addante, Javier Lopez-Calderon, Nathan Allen, Carter Luck, Alana Muller, Lindsey Sirianni, Cory S. Inman, Daniel L. Drake

Psychology Student Publications

Non-conscious processing of human memory has traditionally been difficult to objectively measure and thus understand. A prior study on a group of hippocampal amnesia (N = 3) patients and healthy controls (N = 6) used a novel procedure for capturing neural correlates of implicit memory using event-related potentials (ERPs): old and new items were equated for varying levels of memory awareness, with ERP differences observed from 400 to 800 ms in bilateral parietal regions that were hippocampal-dependent. The current investigation sought to address the limitations of that study by increasing the sample of healthy subjects (N = …

Destined Failure, Chengjun Pan

Masters Theses

I attempt to examine the complex structure of human communication, explaining why it is bound to fail. By reproducing experienceable phenomena, I demonstrate how they can expose communication structure and reveal the limitations of our perception and symbolization.I divide the process of communication into six stages: input, detection, symbolization, dictionary, interpretation, and output. In this thesis, I examine the flaws and challenges that arise in the first five stages. I argue that reception acts as a filter and that understanding relies on a symbolic system that is full of redundancies. Therefore, every interpretation is destined to be a deviation.

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 …

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 …