Social and Behavioral Sciences Commons^™

Associations Between Early Childhood Sleep, Memory Function, And Brain Development Across The Nap Transition, Sanna Lokhandwala

Doctoral Dissertations

Preschool-age children often distribute their sleep across a midday nap and overnight sleep. Skipping the nap is suggested to increase the duration and depth of deep sleep (i.e., slow wave activity; SWA). Moreover, missing the midday nap has been shown to impair learning processes. This may be because children’s brains at this point in development are immature, necessitating the intervening nap period to strengthen memories before they are forgotten. Nonetheless, at some point during the preschool years, many children begin transitioning naturally out of napping. It is unclear whether the memory benefits of overnight SWA after a skipped nap depend …

Motivated Attention To Social And Nonsocial Reward Images: Examining Relations With Externalizing Risk In Children, Adaeze C. Egwuatu

Doctoral Dissertations

Children that exhibit issues with externalizing behaviors often experience maladaptive outcomes in later life. Externalizing problems during middle childhood (e.g., 6-10 years old) are linked to issues with emotion regulation, which are, in turn, caused by disrupted attention and emotion reactivity to reward. Externalizing problems during this period have also been linked diminished processing of social reward stimuli, suggesting externalizing risk in children may be reflected in contrasting patterns in processing of non-social and social rewards. However, research comparing how differences in affective processing of specific reward content (i.e. social versus non-social) patterns relate to externalizing behavior within normative development …

Mental Fatigue: Examining Cognitive Performance And Driving Behavior In Young Adults, Abigail F. Helm

Doctoral Dissertations

Mental fatigue causes an increase in task-based EEG theta and alpha power and a decrease in performance (for a review, see Tran et al., 2020). However, little is known about the emergence of mental fatigue in resting state EEG recordings and whether the progression of mental fatigue over time is influenced by individual differences. The current dissertation examined the utility of resting state EEG as a measure of mental fatigue by testing whether EEG power changed in young adults over the course of a cognitively demanding battery of tasks. The current dissertation also tested how this measure of mental fatigue …

Shared Neural Substrates Of Perception And Memory: Testing The Assumptions And Predictions Of The Representational-Hierarchical Account, D. Merika W. Sanders

Doctoral Dissertations

Proponents of the representational-hierarchical (R-H) account claim that memory and perception rely on shared neural representations. In the ventral visual stream, posterior brain areas are assumed to represent simple information (e.g. low-level image properties), but the complexity of representations increases toward more anterior areas, such as inferior temporal cortex (e.g., object-parts, objects), extending into the medial temporal lobe (MTL; e.g. scenes). This view predicts that brain structures along this continuum serve both memory and perception; a structure’s engagement is determined by the representational demands of a task, rather than the cognitive process putatively involved. In a neuroimaging study, I searched …

How Perception Of Decision Environment And Future Information Affects Changes In Delay Discounting Rates: Differences Across U.S. And China, Differences Before And After The U.S. 2018 Midterm Elections, Fran Walsh

Masters Theses

In this thesis, I will explore the idea that choices between present, smaller value options and future, larger value options depend on how much individuals trust the future to deliver the reward. Due to this aspect of trust, the individual must build their estimate of trust based on information for their present environment and their future expectations. This estimate of future trust can change across different time points in the same environment (i.e., before and after a national election) and between environments in the same time point (i.e., between two countries experiencing different economic rates of change). In this set …

Changes In Color Guidance Over The Course Of A Complex Visual Search, Ryan Papargiris

Masters Theses

When searching for an object, we store a mental representation of the target, which guides our search through the use of attention. The effectiveness of this search guidance varies depending on the task and the relationship between target and distractors. With a better understanding of how search guidance changes over time within a trial, we can better compare the differences between experimental conditions. Eye tracking data from a variety of search tasks were analyzed to determine how color guidance varied over the course of the trial. Color guidance for a given fixation was evaluated based on the distance in color …

One Year Change In Cognitive Function In Male And Female Common Marmosets (Callithrix Jacchus), Brianna Healey

Masters Theses

Long term cognitive studies in humans and nonhuman primates such as macaques are difficult because of their long lifespan. The common marmoset (Callithrix jacchus) is a non-human primate who shares with humans many features characteristic of primates, including a complex brain and cognitive function. They also have a short lifespan (~10 years) that makes them a great model in studies of cognitive aging. This study focuses on the rate of decline in cognitive function in male and female marmosets based on performance on reversal learning tasks over 2 years of testing.

We found that marmosets improved their overall …

Hearing And Seeing A Speaker: How Perceptual And Cognitive Factors Modulate The Dynamics Of Audiovisual Speech Perception, Elina Kaplan

Doctoral Dissertations

In face-to-face conversations, listeners process and combine speech information obtained from hearing and seeing the speaker talk. Audiovisual speech typically leads to more robust recognition of speech, as it provides more information for recognition but also as it helps listeners adjust to speaker idiosyncrasies. The goal of the current thesis was to examine how certain perceptual and cognitive factors modulate how listeners use visual speech to facilitate momentary speech perception and to adjust to a speaker’s idiosyncrasies. Results showed that (older) listeners’ sensitivity to cross-modal synchrony is related to the size of the audiovisual interactions during early perceptual processing. Furthermore, …

Effort-Related Motivational Dysfunctions: Behavioral And Neurochemical Studies Of The Wistar-Kyoto Rat Model Of Depression, Brendan Abbott

Masters Theses

Depression and related disorders are characterized by motivational dysfunctions, including deficits in behavioral activation and exertion of effort. Animal models of relevance to depression represent a critical starting point in elucidating the neurobiological mechanisms underlying motivational dysfunctions. The present study explored the use of the Wistar-Kyoto (WKY) animal model of depression to examine effort-related functions as measured by voluntary wheel running and performance on a mixed fixed ratio 5/progressive ratio (FR5/PR) operant task. Given the known link between activational aspects of motivation and the mesocorticolimbic dopamine (DA) system, the behavioral effects of d-amphetamine (0.5 and 1.0 mg/kg, IP), a psychostimulant …

Assessing The Long-Term Sequelae Of Mild Traumatic Brain Injury, Janna Mantua

Doctoral Dissertations

A mild traumatic brain injury (mTBI), also known as a concussion, is defined as an injury that results in an alteration of consciousness or mental status. Previous studies have shown mTBI populations experience a number of chronic (> 1 year) symptoms, such as sleep disturbances (e.g., sleep stage alterations), mood alterations (e.g., depressive symptoms), and cognitive alterations (e.g., poor concentration). The three chapters of this dissertation sought to explore these long-term sequelae and the possible interrelations between them. In the first experiment, sleep-dependent memory consolidation of neutral stimuli was probed in a chronic mTBI sample and a control, uninjured sample. …

A Representational-Hierarchical Account: A New Theory Of False Memories, D. Merika Wilson

Masters Theses

Past research has supported a representational-hierarchical theory of memory and perception that extends the ventral visual stream into the medial temporal lobe. In this account, representations are organized in a hierarchical manner, such that structures located further anterior in the brain contain complex representations of whole objects and areas further posterior in the visual cortex contain representations of simple features. When conjunctive representations are compromised, an individual must rely on simple-feature representations to complete mnemonic and perceptual tasks. However, these simple-feature representations are susceptible to feature-level interference, which can cause false recognition of novel objects. The goal of the present …

The Neural Correlates Of Emotion Reactivity And Regulation In Young Children With Adhd, Claudia I. Lugo-Candelas

Doctoral Dissertations

Attention-deficit hyperactivity disorder (ADHD) is the most frequently occurring pediatric neurobehavioral disorder. Although emotion reactivity and regulation are frequently impaired in ADHD, few studies have examined these factors in preschool aged children with ADHD, and none have explored the neural correlates of emotion reactivity and regulation in this group though event-related potentials (ERPs). Children aged 4 to 7 with (n = 24) and without (n = 30) ADHD symptoms completed an attention task composed of four blocks: baseline, frustration, suppression, and recovery. In the frustration and suppression blocks, negative affect was induced by false negative feedback. During the …

Behavioral And Neural Mechanisms Of Impulsive Choice, Jesse Mcclure

Doctoral Dissertations

Impulsive choice is defined as the preference for a small immediate reward over a larger delayed reward. Individual variablity in impulsive choice correlates with many socially relevant behaviors. Although forms of impulsive choice have been studied in both behavioral ecology and psychology, the exchange of knowledge between these fields is just beginning. Drawing from both of these fields will improve our research methods allowing for a more detailed understanding of this complex behavior. Existing tasks to measure impulsive choice conflate the delay and quantity of the reward. To address this, I have drawn from foraging research to establish a method …

Estrogen-Sensitive Learning Is Not Affected By Combination Ethinyl Estradiol And Levonorgestrel Oral Contraceptive Use, Darlene F. Ficco

Doctoral Dissertations

Two studies were conducted to explore the cognitive effects of combination ethinyl estradiol and levonorgestrel contraceptive use during late adolescence and young adulthood. Three groups of females, naturally cycling, active pill phase, and hormone-free interval phase, were tested on a battery of estrogen-sensitive, i.e., place learning and word generation, and estrogen-insensitive, i.e., map drawing, mental rotation, digit span, story recall, and object recall, tasks. Study 2 was conducted as a means to replicate the findings observed in Study 1 and to manipulate task difficulty and sensitivity. Two measures of mood were administered, and salivary estradiol levels at time of testing …

Attention Modulates Erp Indices Of The Precedence Effect, Benjamin H. Zobel

Masters Theses

When presented with two identical sounds from different locations separated by a short onset asynchrony, listeners report hearing a single source at the location of the lead sound, a phenomenon called the precedence effect (Wallach et al., 1949; Haas, 1951). When the onset asynchrony is above echo threshold, listeners report hearing the lead and lag sounds as separate sources with distinct locations. Event-related potential (ERP) studies have shown that perception of separate sound sources is accompanied by an object-related negativity (ORN) 100-250 ms after onset and a late posterior positivity (LP) 300-500 ms after onset (Sanders et al., 2008; Sanders …