Thesis (Ph. D.)--Illinois State University, 1998. / Title from title page screen, viewed July 14, 2006. Dissertation Committee: Jeff Laurent, Salvatore J. Catanzaro (co-chairs), Connie B. Horton, Alvin E. House. Includes bibliographical references (leaves 70-83) and abstract. Also available in print.

There is a body of research on the effect of physical activity oncognition in the old adult population. Less research areconducted on adolescents. The aim for this study is to find out ifadolescents long-term memory is affected by physical activity.144 pupils were asked to rate their physical activity each week.Thereafter their long- term memory was tested through tests onepisodic- and semantic memory. The results showed that thosewho are physically active more than 4 hours had a better scoreon part of the semantic test but no effect was found in theepisodic test. This result indicates that physical activity not onlyaffects working memory, as was shown by previous research butalso has an effect in parts of the semantic long-term memory.

This thesis is an investigation of the proximate mechanisms and ultimate functions of memory for emotional events. The theoretical basis of this Thesis is that in order to reach a full understanding of a biological phenomenon, it is important that both proximate and ultimate (functional) explanations for that phenomenon are explored. Chapters 2 and 3 present an examination of the proximate mechanisms involved in memory consolidation of emotional events. In Chapter 2, three experiments are presented each testing the hypothesis that stress hormone activation immediately following viewing an emotional event enhances memory for that event. Each of the three experiments failed to find an enhancing effect of stress hormone activation on memory consolidation. Chapter 3 describes an investigation into whether the reduced feedback from the body to the brain, which occurs as a result of total spinal cord transection, diminishes the intensity of emotional experience and therefore impairs memory for emotional events. The results of this investigation revealed no differences between spinal cord transection patients and matched control participants in emotional expressivity, emotional awareness and in memory for emotional material. Chapters 4 and 5 explore how memory and emotion may interact differently for males and females and in manner that facilitates their survival and reproduction. Evolutionary theory argues that males should be more concerned than females about threats to their social status, whereas females should be more concerned about threats to their physical appearance and sexual reputation. Chapter 4 describes two experiments testing whether a) males have enhanced emotional arousal and memory for words implying they are of low social status; b) females have enhanced emotional arousal and memory for words implying they are physically unattractive and sexually untrustworthy. The results of these experiments showed that females had enhanced memory for words relating to physical appearance, and partial evidence that males have 2 enhanced memory for words relating to social status. Chapter 5 tests the evolutionary theory that males should be more emotionally aroused and thus have greater memory for cues relating to sexual infidelity (the thought of their partner having sex with another man), whereas females should be more emotionally aroused and have greater memory for cues to emotional infidelity (the thought of their partner forming a close emotional attachment with another woman). It also examines whether relationship status affects emotional arousal and memory for these cues. The results did not find any support for these hypothesised sex difference in memory. However, those ‘currently in a relationship’ did show enhanced emotional arousal to cues to sexual infidelity compared to those ‘currently not in a relationship’. Chapter 6 presents an investigation concerning the evolutionary hypothesis that individuals tend to have enhanced recognition memory for the faces of deceivers or ‘liars’. This chapter describes a study in which participants viewed a series of short video clips of individuals, half of whom were lying, half telling the truth. Participants’ memory for the individuals that appeared in the video clips was tested but there was no evidence of enhanced memory for the faces of ‘liars’. Chapter 7 provides a general discussion of the findings of this thesis. The failure to find an enhancing effect of post learning stress hormone activation on memory for emotional material, and the failure to find an impairment in memory for emotional material in people with total spinal cord transection contradict two established views on the proximate mechanisms involved in emotion, and emotions effect of the brain. How these findings relate to the established mainstream views on emotion and memory are discussed. The findings of studies concerning the functional interaction of memory and emotion presented in this thesis are also discussed in relation to previous research.

Experimental evidence was needed to help answer the question of whether the decrease in retention from Trial 1 to Trial 2 was caused by PI from Trial 1 decreasing retention of Trial 2, or by a primacy effect increasing retention of Trial 1 over the natural retention baseline of a S. The present experiment was designed to help answer this question.

In this dissertation, we present a number of studies that primarily focus on data movement challenges among different types of memories (viz., 3D-DRAM, DDRx DRAM and NVM) employed together as a flat-address heterogeneous memory system. We introduce two different hardware-based techniques for prefetching data from slow off-chip phase change memory (PCM) to fast on-chip memories. The prefetching techniques efficiently fetch data from PCM and place that data into processor-resident or 3D-DRAM-resident buffers without putting high demand on bandwidth and provide significant performance improvements. Next, we explore different page migration techniques for flat-address memory systems which differ in when to migrate pages (i.e., periodically or instantaneously) and how to manage the migrations (i.e., OS-based or hardware-based approach). In the first page migration study, we present several epoch-based page migration policies for different organizations of flat-address memories consisting of two (2-level) and three (3-level) types of memory modules. These policies have resulted in significant energy savings. In the next page migration study, we devise an efficient "on-the-fly'" page migration technique which migrates a page from slow PCM to fast 3D-DRAM whenever it receives a certain number of memory accesses without waiting for any specific time interval. Furthermore, we present a light-weight hardware-assisted address reconciliation process for address management of the migrated pages. Such an on-the-fly page migration with hardware-assisted address reconciliation technique provides significant performance improvement over systems using epoch-based page migration and OS-based address management. Finally, we have developed an analytical model, which employs offline analyses of memory access counts per page and recommends whether an application is migration friendly or not. This can be useful in deciding if page migration (either epoch-based or on-the-fly based) should be used or turned off for a given application. Thus, our data management techniques and model enable significant performance improvements for flat-address heterogeneous memory systems involving NVMs.

Among the key challenges of computing today are the emergence of many-core architectures and the resulting need to effectively exploit explicit parallelism. Indeed, programmers are striving to exploit parallelism across virtually all platforms and application domains. The shared memory programming model effectively addresses the parallelism needs of mainstream computing (e.g., portable devices, laptops, desktop, servers), giving rise to a growing ecosystem of shared memory parallel techniques, tools, and design practices. However, to meet the extreme demands for processing and memory of critical problem domains, including scientific computation and data intensive computing, computing researchers continue to innovate in the high-end distributed memory architecture space to create cost-effective and scalable solutions. The emerging distributed memory architectures are both highly parallel and increasingly heterogeneous. As a result, they do not present the programmer with a cache-coherent view of shared memory, either across the entire system or even at the level of an individual node. Furthermore, it remains an open research question which programming model is best for the heterogeneous platforms that feature multiple traditional processors along with accelerators or co-processors. Hence, we have two contradicting trends. On the one hand, programming convenience and the presence of shared memory     call for a shared memory programming model across the entire heterogeneous system. On the other hand, increasingly parallel and heterogeneous nodes lacking cache-coherent shared memory call for a message passing model. In this dissertation, we present the architecture of Samhita, a distributed shared memory (DSM) system that addresses the challenge of providing shared memory for non-cache-coherent systems. We define regional consistency (RegC), the memory consistency model implemented by Samhita. We present performance results for Samhita on several computational kernels and benchmarks, on both cluster supercomputers and heterogeneous systems. The results demonstrate the promising potential of Samhita and the RegC model, and include the largest scale evaluation by a significant margin for any DSM system reported to date. / Ph. D.

Low-frequency (LF) words have higher hit rates (HRs) and lower false alarm rates (FARs) than high-frequency (HF) words in recognition memory, a phenomenon termed the mirror effect by Glanzer and Adams (1985). The primary mechanism for producing the mirror effect varies substantially across models of recognition memory, with some models localizing the effects during encoding and others during retrieval. The current experiments contrast two retrieval-stage models, the Source of Activation Confusion (SAC; Reder, Nhouyvanisvong, Schunn, Ayers, Angstadt, & Hiraki, 2000) model and the unequal variance signal detection theory (UVSDT) criterion shift model (e.g., DeCarlo, 2002). The SAC model proposes that two distinct processes underlie the HR and FAR effects, with a familiarity process driving the FAR effect and a recollective process driving the HR effect. The UVSDT criterion shift model assumes that subjects use different criteria when making recognition judgments for HF and LF words, with this single process driving both the HR and FAR effects. Experiment 1 incorporated divided attention and speeded responding manipulations designed to remove the contribution of recollection in the SAC model, thereby eliminating the LF HR advantage. Experiment 2 manipulated the salience of the frequency classes, as the UVSDT criterion shift model requires that subjects are aware of the distinct frequency classes in order to shift their criteria. Across both experiments, model simulations and direct fits of the SAC model demonstrated systematic errors in prediction. While the UVSDT model struggled in fits to Experiment 1 data, the model provided acceptable fits to Experiment 2 data and accurately predicted the general pattern of effects in all cases. Furthermore, state-trace analyses provided compelling evidence in favor of single-process rather than dual-process models of recognition memory, casting serious doubt on the validity of the dual-process SAC model. Finally, the current experiments highlight the importance of obtaining model-based estimates of sensitivity and bias across frequency classes, as the standard practice of conducting direct comparisons of HRs and FARs for HF and LF words confounds bias and sensitivity differences.

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This essay examines the concept of memory through a literature study of articles in three prominent archival journals. The aim of the study is to investigate if, and in that case how, the concept of memory is made visible in relation to archives as an institution and collection in three archival journals. The three archival journals that are under examination are Archival Science, American Archivist and Archivaria, with articles published between the years of 2013 to 2020. My study follows the previous research of Trond Jacobsen, Ricardo L. Punzalan and Margaret L. Hedstrom in the 2013 article Invoking ‘‘collective memory’’: mapping the emergence of a concept in archival science. My essay examines the seven following years; 2013-2020. This essay aims to provide a broader view of memory in archival science as it focuses on the concept of memory instead of “collective memory”. Three themes are found and examined; memory and identity, remembering and forgetting, and the archivist’s role in the establishment of memory. Assmann (2006; 2011) uses four different memory formations to illustrate the complexity of the concept. Jimerson (2009) also gives the study a theoretical framework by explaining the power structure and the relationship between the archivist and the concept of memory. The results show that the concept of memory is complex and that there are multiple definitions and understandings of memory. To use a universal definition of the concept of memory is problematic because of it’s multiple understandings. This thesis agrees with the articles examined in that we need interdisciplinary views on how the concept of memory is made visible in relation to archives as an institution and collection, and that archivists need broader tools of how to understand and problematize the concept of memory.

published_or_final_version / abstract / Computer Science / Doctoral / Doctor of Philosophy