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The brain is a fundamental target of the stress response that promotes adaptation and survival but the repeated activation of the stress response has the potential alter cognition, emotion, and motivation, key functions of the limbic system. Three structures of the limbic system in particular, the hippocampus, medial prefrontal cortex

The brain is a fundamental target of the stress response that promotes adaptation and survival but the repeated activation of the stress response has the potential alter cognition, emotion, and motivation, key functions of the limbic system. Three structures of the limbic system in particular, the hippocampus, medial prefrontal cortex (mPFC), and amygdala, are of special interest due to documented structural changes and their implication in post-traumatic stress disorder (PTSD). One of many notable chronic stress-induced changes include dendritic arbor restructuring, which reflect plasticity patterns in parallel with the direction of alterations observed in functional imaging studies in PTSD patients. For instance, chronic stress produces dendritic retraction in the hippocampus and mPFC, but dendritic hypertrophy in the amygdala, consistent with functional imaging in patients with PTSD. Some have hypothesized that these limbic region's modifications contribute to one's susceptibility to develop PTSD following a traumatic event. Consequently, we used a familiar chronic stress procedure in a rat model to create a vulnerable brain that might develop traits consistent with PTSD when presented with a challenge. In adult male rats, chronic stress by wire mesh restraint (6h/d/21d) was followed by a variety of behavioral tasks including radial arm water maze (RAWM), fear conditioning and extinction, and fear memory reconsolidation to determine chronic stress effects on behaviors mediated by these limbic structures. In chapter 2, we corroborated past findings that chronic stress caused hippocampal CA3 dendritic retraction. Importantly, we present new findings that CA3 dendritic retraction corresponded with poor spatial memory in the RAWM and that these outcomes reversed after a recovery period. In chapter 3, we also showed that chronic stress impaired mPFC-mediated extinction memory, findings that others have reported. Using carefully assessed behavior, we present new findings that chronic stress impacted nonassociative fear by enhancing contextual fear during extinction that generalized to a new context. Moreover, the generalization behavior corresponded with enhanced functional activation in the hippocampus and amygdala during fear extinction memory retrieval. In chapter 5, we showed for the first time that chronic stress enhanced amygdala functional activation during fear memory retrieval, i.e., reactivation. Moreover, these enhanced fear memories were resistant to protein synthesis interference to disrupt a previously formed memory, called reconsolidation in a novel attempt to weaken chronic stress enhanced traumatic memory. Collectively, these studies demonstrated the plastic and dynamic effects of chronic stress on limbic neurocircuitry implicated in PTSD. We showed that chronic stress created a structural and functional imbalance across the hippocampus, mPFC, and amygdala, which lead to a PTSD-like phenotype with persistent and exaggerated fear following fear conditioning. These behavioral disruptions in conjunction with morphological and functional imaging data reflect a chronic stress-induced imbalance between hippocampal and mPFC regulation in favor of amygdala function overdrive, and supports a novel approach for traumatic memory processing in PTSD.
ContributorsHoffman, Ann (Author) / Conrad, Cheryl D. (Thesis advisor) / Olive, M. Foster (Committee member) / Hammer, Jr., Ronald P. (Committee member) / Sanabria, Federico (Committee member) / Arizona State University (Publisher)
Created2013
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Description
Incidental learning of sequential information occurs in visual, auditory and tactile domains. It occurs throughout our lifetime and even in nonhuman species. It is likely to be one of the most important foundations for the development of normal learning. To date, there is no agreement as to how incidental learning

Incidental learning of sequential information occurs in visual, auditory and tactile domains. It occurs throughout our lifetime and even in nonhuman species. It is likely to be one of the most important foundations for the development of normal learning. To date, there is no agreement as to how incidental learning occurs. The goal of the present set of experiments is to determine if visual sequential information is learned in terms of abstract rules or stimulus-specific details. Two experiments test the extent to which interaction with the stimuli can influence the information that is encoded by the learner. The results of both experiments support the claim that stimulus and domain specific details directly shape what is learned, through a process of tuning the neuromuscular systems involved in the interaction between the learner and the materials.
ContributorsMarsh, Elizabeth R (Author) / Glenberg, Arthur M. (Thesis advisor) / Amazeen, Eric (Committee member) / Brewer, Gene (Committee member) / Arizona State University (Publisher)
Created2013
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Description
Most people are experts in some area of information; however, they may not be knowledgeable about other closely related areas. How knowledge is generalized to hierarchically related categories was explored. Past work has found little to no generalization to categories closely related to learned categories. These results do not fit

Most people are experts in some area of information; however, they may not be knowledgeable about other closely related areas. How knowledge is generalized to hierarchically related categories was explored. Past work has found little to no generalization to categories closely related to learned categories. These results do not fit well with other work focusing on attention during and after category learning. The current work attempted to merge these two areas of by creating a category structure with the best chance to detect generalization. Participants learned order level bird categories and family level wading bird categories. Then participants completed multiple measures to test generalization to old wading bird categories, new wading bird categories, owl and raptor categories, and lizard categories. As expected, the generalization measures converged on a single overall pattern of generalization. No generalization was found, except for already learned categories. This pattern fits well with past work on generalization within a hierarchy, but do not fit well with theories of dimensional attention. Reasons why these findings do not match are discussed, as well as directions for future research.
ContributorsLancaster, Matthew E (Author) / Homa, Donald (Thesis advisor) / Glenberg, Arthur (Committee member) / Chi, Michelene (Committee member) / Brewer, Gene (Committee member) / Arizona State University (Publisher)
Created2013
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Description
An introduction to neuroscientific thought aimed at an audience that is not educated in biology. Meant to be readable and easily understood by anyone with a high school education. The first section is completed in its entirety, with outlines for the proposed final sections to be completed over the next

An introduction to neuroscientific thought aimed at an audience that is not educated in biology. Meant to be readable and easily understood by anyone with a high school education. The first section is completed in its entirety, with outlines for the proposed final sections to be completed over the next few years.
ContributorsNelson, Nicholas Alan (Author) / Olive, M. Foster (Thesis director) / Brewer, Gene (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor)
Created2014-05
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ContributorsChandler, N. Kayla (Author) / Neisewander, Janet (Thesis director) / Sanabria, Federico (Committee member) / Olive, M. Foster (Committee member) / Barrett, The Honors College (Contributor) / College of Liberal Arts and Sciences (Contributor)
Created2013-05
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Description
It has been suggested that directed forgetting (DF) in the item-method paradigm results from selective rehearsal of R items and passive decay of F items. However, recent evidence suggested that the passive decay explanation is insufficient. The current experiments examined two theories of DF that assume an active forgetting process:

It has been suggested that directed forgetting (DF) in the item-method paradigm results from selective rehearsal of R items and passive decay of F items. However, recent evidence suggested that the passive decay explanation is insufficient. The current experiments examined two theories of DF that assume an active forgetting process: (1) attentional inhibition and (2) tagging and selective search (TSS). Across three experiments, the central tenets of these theories were evaluated. Experiment 1 included encoding manipulations in an attempt to distinguish between these competing theories, but the results were inconclusive. Experiments 2 and 3 examined the theories separately. The results from Experiment 2 supported a representation suppression account of attentional inhibition, while the evidence from Experiment 3 suggested that TSS was not a viable mechanism for DF. Overall, the results provide additional evidence that forgetting is due to an active process, and suggest this process may act to suppress the representations of F items.
ContributorsHansen, Whitney Anne (Author) / Goldinger, Stephen D. (Thesis advisor) / Azuma, Tamiko (Committee member) / Brewer, Gene (Committee member) / Homa, Donald (Committee member) / Arizona State University (Publisher)
Created2011
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Description
Prospective memory is defined as the process of remembering to do something at a particular point in the future after first forming a conscious intention. There are three types of prospective memory intentions; event-based, time-based and activity-based intentions. Research has suggested that activity-based is one of the dominant prospective memory

Prospective memory is defined as the process of remembering to do something at a particular point in the future after first forming a conscious intention. There are three types of prospective memory intentions; event-based, time-based and activity-based intentions. Research has suggested that activity-based is one of the dominant prospective memory failures that people self-report yet there is little research on this area of prospective memory. The current study focuses on how activity-based PM is influenced by the association between the match of internal context and intended action. According to previous research, similar context between intention formation and retrieval has been shown to facilitate prospective memory, which increases the execution of intentions. Based on literature, we hypothesized that there would be higher intention completion when the internal context matches the intended action to be completed in the future. Results showed that internal context affected activity-based intention completion significantly. However the interaction between internal context and the intended action did not significantly affect intention completion. Although we did not get the hypothesized interaction, the means do cross over showing the interaction pattern is there. We decided to treat this as a pilot study and replicate it with a well-powered experiment consisting of 560 valid participants.
ContributorsEdrington, Alexis Adele (Author) / Brewer, Gene (Thesis director) / Presson, Clark (Committee member) / McClure, Samuel (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor) / College of Liberal Arts and Sciences (Contributor)
Created2015-12
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Description
Music and emotions have been studied frequently in the past as well as music and memory. However, these three items don’t have as much research grouped together. Further, this research does not also encompass culture. In my research, the aim was to examine the relationship between music, memory, emotion, and

Music and emotions have been studied frequently in the past as well as music and memory. However, these three items don’t have as much research grouped together. Further, this research does not also encompass culture. In my research, the aim was to examine the relationship between music, memory, emotion, and culture of gender. The hypothesis was that women had more emotions linked to music than men. We gave 416 students an animal fluency task, a letter fluency task, six cultural fluency tasks, and a cultural identity survey. We used a t-test and created a graph to analyze my data. After administering my tasks, we found that women had recalled more adjectives linked to music than men. However, there was not a statistically significant difference between the number of adjectives with emotional valence between men and women, indicating that there was no relationship between gender and emotion in regards to music. The limitations on this study included the descriptions on how to complete the task, the cultural norms of the participants, and the disparity between the number of female and male participants. In a future study, it is necessary to be more specific in what is desired from the participants and to pay close attention to shifting gender norms. Further, we would also like to see how the results from future research can impact music therapy for memory-related mood disorders.
ContributorsLevin, Allison (Author) / Brewer, Gene (Thesis director) / Cohen, Adam (Committee member) / Sanford School of Social and Family Dynamics (Contributor) / Department of Psychology (Contributor) / College of Integrative Sciences and Arts (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
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Description
The locus coeruleus-norepinephrine system (LC-NE) has been argued to play a vital role in task engagement and attention control by the adaptive gain theory (Aston-Jones & Cohen, 2005). One of the central claims of this theory is that tonic LC activity exhibits a quadratic relationship with task performance. Pupil dynamics

The locus coeruleus-norepinephrine system (LC-NE) has been argued to play a vital role in task engagement and attention control by the adaptive gain theory (Aston-Jones & Cohen, 2005). One of the central claims of this theory is that tonic LC activity exhibits a quadratic relationship with task performance. Pupil dynamics have been correlated to LC-NE activity via primate intracranial recordings in ways that provide evidence for the adaptive gain theory. Due to the small size and location of the LC, less is known about LC functioning in humans, leading to a desire to find valid, noninvasive psychophysiological proxies to study this structure. In this paper we performed a replication of Murphy, Robertson, Balsters, & O’Connell (2011) to gather evidence on whether pupil fluctuations and the P3 event-related potential are viable markers for measuring tonic and phasic LC-NE activity in humans. A sample of 33 subjects from the Arizona State University human subjects pool provided usable electroencephalogram and pupillometry data collected during an auditory oddball task. Our analyses largely correspond with those found in Murphy et al. (2011) showing some evidence that pupillometry and P3 can be utilized when studying the LC. Moving forward we will reproduce the full set of analyses from Murphy et al. (2011) with our dataset.
ContributorsStrayer, Deanna L. (Author) / Brewer, Gene (Thesis director) / Robison, Matthew (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
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Description
Although it has recently been demonstrated that source monitoring (SM) processes may mediate the relationship between working memory (WM) and false memories, little research has investigated whether the quality of monitoring processes can account for this reduction. In the current study, participants performed multiple false memory, WM, and SM tasks.

Although it has recently been demonstrated that source monitoring (SM) processes may mediate the relationship between working memory (WM) and false memories, little research has investigated whether the quality of monitoring processes can account for this reduction. In the current study, participants performed multiple false memory, WM, and SM tasks. Consistent with previous research, SM abilities mediated the relationship between WM and false memories (regardless of whether or not participants were warned of the illusions at encoding). High SM individuals were better able to recall contextual information from study to correctly reject lures, whereas low SM individuals were more likely to rely on the quality of retrieved details to reject lures. These results suggest that individuals low and high in SM abilities rely on qualitatively different monitoring processes to reduce errors, and that individual differences in diagnostic monitoring strategies may account for previous relationships found between WM and false memories.
ContributorsCoulson, Allison Rose (Author) / Brewer, Gene (Thesis director) / Ellis, Derek (Committee member) / Department of Psychology (Contributor) / School of Public Affairs (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05