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Feigenbaum, J. D. "Information processing in the hippocampus and parahippocampal gyrus of the behaving primate." Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235039.
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Scott, Anne Grete. "Monkeys, movements, and memories: Behavioral sequences and short-term memory in aged monkeys." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185189.
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Six young and six old squirrel monkeys were tested on two different short-term memory tasks. One was a two-choice problem, the other a nine-choice problem. A baseline, or one-choice, problem was also included. A video camera recorded all behaviors displayed by the monkeys during testing. Behaviors coded were turning, aggression, displacement, exploratory, huddling, orienting, locomotion, screen activities, and visual scanning. Also recorded was correct or incorrect choice and whether the animal showed evidence of seeing the cue stimulus. Old animals committed more errors during both phases of the experiment. Older animals were also more likely to engage in active behaviors, such as turning, whereas young animals were more likely to manifest less active behaviors, such as visual scanning and orienting. Young animals were also more likely to see the stimulus. A path analytic procedure was used to determine direct effects of age on performance and indirect effects mediated through behaviors manifested prior to the choice. For the two-choice problem, approximately half of the age effects on performance were attributable to indirect effects. For the nine-choice problem almost three quarters of the age effects on performance were attributable to indirect effects. These findings indicate that age differences in short-term memory performance are not direct effects of age alone. The age effect also occurs because age affects the behaviors of the monkeys and that these behaviors have a large effect on subsequent memory performance.
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BAILEY, CATHERINE SUZANNE. "DEVELOPMENT OF SPATIAL MEMORY STRATEGIES IN SQUIRREL MONKEYS (COGNITIVE MAP)." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184043.
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When different development rates for psychological processes such as those in spatial memory exist, they can be linked to relevant brain areas via their different developmental rates. The hippocampus and caudate nucleus have been implicated in allocentric and egocentric spatial behavior changes found in youth and old age. Variation in allocentric and egocentric behavior in squirrel monkeys due to age was examined using a quadruple T-maze and animals in three age groups: 0.3 - 4 year olds, (n = 12), 5 - 10 year olds (n=12) and 11 - 17 year olds (n = 12). Subjects were trained to go to one of three goals in the maze from one of two training release locations. When they reached criterion for consistent responding, they were given probe trials pseudorandomly interspersed with the training trials in which they were released from one of the three other locations. The 12 test sessions were divided into three phases consisting of four sessions each. A 3 (age groups) x 3 (probe sites) x 3 (phases) mixed design ANOVA with repeated measures on the second and third factors revealed only a significant effect for probe site (F(1,33) = 14.55, p < .01) sing the Geisser-Greenhouse correction for heterogeneity of variance. The pattern of responding most clearly resembled route and was stable over testing. Age was not significant although there was a trend toward random behavior in young and more route-like behavior in older animals. Intrinsic maze cues effects on responding were examined. These data were analyzed using a 3 (age groups) x 2 (training groups) x 3 (probe sites) mixed design ANOVA with repeated measures on the last factor, and again revealed only a significant probe site effect (F(1,33) = 14.55, p < .01). Thus cues intrinsic to the maze did not affect response pattern. Only 13 subjects clearly used one of the three spatial strategies: 6 route, 3 direction, and 4 place. Of the remaining 23 animals 11 were young, 5 were adult and 7 were mature. Two used a variation of place, three used a combination of strategies, four were idiosyncratic, 10 used proto-route (route-like, but not systematic enough to be route) and three were random. The use of place strategy by animals as young as 4 and as old as approximately 17 implicates hippocampal changes occurring outside this age range.
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Harrison, Kathryn. "Skills used in food processing by vervet monkeys, Cecropithecus aethiops." Thesis, University of St Andrews, 1997. http://hdl.handle.net/10023/2636.
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The principle objective of this study was to describe and record all the gathering and processing skills of vervet monkeys for a variety of different foods. The study was conducted on two troops of vervet monkeys living in the Palmiet Valley, Natal, South Africa. There was sufficient data to analyze the processing of four foods of differing complexity; termites, leaf shoots, sugarcane and fruit. Milton (1988) proposed that the intellectual difficulties of finding and processing food led to the evolution of intelligence. In the only study of food processing skill, Byrne and Byrne (1993) showed that gorillas use a hierarchical organization perhaps reflecting imitation at the program-level. The question to be asked in this study was, would vervets also organize their processing into a few techniques for specific foods and would it then be possible to identify learning mechanisms used by the monkeys? The current literature suggests that monkeys use simple solutions to their foraging problems, there is no evidence for imitation of feeding skills in monkeys. At the most detailed level of analysis, grip types used in the processing of foods were described. Existing definitions in the literature were not adequate to explain the monkeys' hand use, and new definitions were added. High individual idiosyncrasy was a feature of grip usage across all four foods, although firm conclusions are not possible because of the known effects of sample size. Cluster analysis was considered the most appropriate method to look at individual variation in grip usage. There was an age effect for leaf shoots and sugarcane, with juveniles restricting their usage to the necessary core grips. The hand preferences for individuals across tasks gave no support for the theory of the evolution of laterality presented by MacNeilage et al. (1987). There was a low degree of individual preference for five out of six tasks, with only termite feeding showing a hand preference. There was some evidence for a right hand reaching, left hand manipulation preference, opposite to MacNeilage's prediction. There was an age effect in direction and strength for two tasks, adults having a stronger left hand preference in contrast to a weaker right hand preference in juveniles for leaf shoots and large fruit. Matrices of the transitional probabilities between two elements, were used to construct the common pathways of processing skill for each individual. Flow diagrams were then created to represent the minimal decision processes used by the monkeys. The diagrams were used to compare individuals' choice of pathways. Cluster analysis was used to analyze pathway choice in detail; none of a variety of independent variables could explain the high individual variation. Whether whole foods or just parts of foods were eaten did explain some of the variance for sugarcane and fruit. The most parsimonious explanation is that social enhancement resulting in trial and error learning best described individuals' acquisition of processing skill, although a number of other factors may explain the observed results.
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LANDAU, VIRGINIA ILENE. "THE ADAPTATION OF NEW WORLD MONKEYS TO NEW ENVIRONMENTAL SITUATIONS: FOOD ACQUISITION AND FOOD PROCESSING BEHAVIORS." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184076.
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Food cleaning behavior has been observed among laboratory squirrel monkeys. A Wilcoxon signed-ranks test showed that significantly more cleaning behavior occurred when hard monkey chow pellets and soft fruit were coated with edible debris. Monkeys removed fewer pieces of fruit from a food crock containing fruit coated with edible debris in a timed test. A principal component analysis of the food cleaning behaviors showed two underlying correlated factors. The first factor was the use of the body to clean food. The second factor was the use of the environment to clean food. Two groups of squirrel monkeys, one without previous learners and one with previous learners, were subjects in a fishing study. The presence of previous learners in the social group was not significant for monkeys fishing in water filled crocks. But there was a significant difference in the number of fishing attempts made by the No Previous Learners Group when fishing in wading pools. The Previous Learners group did not make significantly more fishing attempts fishing in wading pools than in crocks. A significant difference was observed in fishing attempts during Phase 1 and Phase 2 of the wading pool experiment for both groups. All monkeys in the group fishing experiments ate fish when it could be obtained. Monkeys who did not learn to fish successfully learned alternative behaviors to obtain fish. The Previous Learners group in the wading pool experiment were subjects in a more difficult fishing test. Significantly fewer fishing attempts were made but the number of monkeys that caught fish was larger. Caged squirrel monkeys scored a lower percentage of fishing attempts than squirrel monkeys living in a social group. While Cebus monkeys caught fish, unlike squirrel monkeys, they did not attempt to eat them.
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Scott, Anne G. (Anne Grete) 1949. "Effects of response bias on learning and memory tasks in squirrel monkeys." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276647.
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Six squirrel monkeys were tested on short-term memory tasks assessing ability to suppress perseverative responses that had been previously reinforced. Each trial was divided into three parts: Initial Preference Assay (IPA), Bias-Conditioning (BC), and Reversal Conditioning (RC), and alternated between two conditions: experimental and control. Strength of response bias (based on choices of response during IPA) exceeded chance levels for each monkey. Eighty-four percent of responses to BC of the experimental trials were made to the response loci chosen in IPA even though that response was not rewarded. Monkeys made 38% correct responses during RC but shifted from making most errors during control trials in the beginning of the experiment to making most errors during experimental trials by the end of the experiment. Monkeys had developed a strategy of persevering from IPA to BC and then shifting to the other, not previously chosen window on RC, which led to correct responses in the experimental trials. (Abstract shortened with permission of author.)
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Brand, Arie Nicolaas. "Memory, information processing and depression." Maastricht : Maastricht : Rijksuniversiteit Limburg ; University Library, Maastricht University [Host], 1987. http://arno.unimaas.nl/show.cgi?fid=5363.
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Nyhus, Erika Marie. "Perceptual processing in recognition memory." Diss., Connect to online resource, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1439459.
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Howells, Glen. "Emotional processing and episodic memory." Thesis, Bournemouth University, 2013. http://eprints.bournemouth.ac.uk/20965/.
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The research reported within this dissertation investigates how individuals’ capacity to assimilate emotionally disruptive events is associated with particular features of episodic and autobiographical memory formation. It is inspired by Rachman’s (1980, 2001) formulation of emotional processing, and his subsequent proposals to explore the general mechanisms by which emotional disruptions are overcome. The specific rationale is informed by multilevel emotion theories, theories of post-traumatic stress disorder, and models of emotional processing. The research considered whether individuals who exhibit signs of a poor emotional processing style tend to encode events generally in a sensory-perceptual manner, with comparative deficits in their capacity to conceptually process data. Methodologically, the studies identify poor and effective emotional processors by using Baker et al.’s (2009) emotional processing scale as a grouping measure. The studies explore differences between groups of poor and effective emotional processors’ performance over a range of memory tasks drawn from episodic and autobiographical memory studies to detect evidence for a sensory- perceptual style of event and stimulus processing which is presumed to be indicated by a surfeit of perceptual details, heightened reported vividness, and a relative lack in conceptual ordering, narrative coherence and verbal indexing. Three general categories of memory are explored: memory for experimentally presented item lists, memory for extended narrative presentations and memory for naturally occurring events retained in long-term autobiographical memory representations. The evidence suggests a tendency to process in a sensory-perceptual manner amongst poor emotional processors for both experimental item lists, as well as in long term autobiographical memory investigations, whereas few differences between groups emerged for the study of narrative recollection. There was little evidence, by contrast, that effective emotional processors were superior at the conceptual processing of events or data. These results are discussed in terms of providing confirmation for information processing accounts of emotional disruptions and disorders which stress the aetiological significance in psychopathological conditions of how events are encoded, rendering such events accessible to broader autobiographical memory bases and conceptual elaboration. Furthermore, the importance of establishing more robust and testable definitions of conceptual processing is stressed.
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Benda, Brian J. "Neural correlates of motor learning/memory in primary motor cortex of macaque monkeys." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9920.
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Threadgold, Emma. "The relationship between processing and memory in working memory development." Thesis, Lancaster University, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.656860.
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Working memory is the ability to simultaneously process and store information (Baddeley, 1986). Complex span tasks, such as reading span, are a widely used paradigm to investigate working memory recall (Daneman & Carpenter, 1980). This thesis presents six experiments that investigate processing and memory relationships in children and adults complex span performance. Experiments 1 to 3 found processing speed significantly influences children's recall in a reading, operation and listening; span task. Evidence is provided for a developmental shift in the importance of processing speed in reading span performance between aged 8- to 14-years-old. However, processing speed is shown to be less important for adults 11' retention in complex span tasks. Furthermore, profiles in the relationship between processing speed and memory are demonstrated to differ according to the type of complex span task, and the relationship between the content of processing and memory. The relationship between the content of processing and memory, influences both children's and adults recall in a complex span task. Memoranda items integrated to the processed element (for example retention of the final word of the processed sentence) are subject to enhanced recall over items independent to the processing. This is demonstrated to be superior in a lexical based span task (reading span) over a non-lexical based span task (operation span). However, mixed evidence is provided in Experiments 2 and 3 for enhanced recall under circumstances in which the memoranda items are semantically associated to the processing. Experiments 4, 5 and 6 investigate the role of pro active interference in complex span task performance. A build up and release of PI is demonstrated in an operation span task, highlighting that inhibition of interference is likely to be a further important factor in complex span task performance.
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Howland, Brian G. "Episodic memory, integrative processing, and memory-contingent brain activity during encoding." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0011629.
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Rangan, Krishna Kumar. "A M-SIMD Intelligent Memory." University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin988225432.
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Kurilla, Brian P. "Processing fluency affects subjective claims of recollection." Diss., Online access via UMI:, 2007.
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Palumbo, Milena. "A comparative analysis of global-local processing in capuchin monkeys (Sapajus Apella) and humans." Thesis, University of Leicester, 2018. http://hdl.handle.net/2381/42816.
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Humans display a global advantage when presented with hierarchical visual patterns. Conversely, capuchin monkeys show a strong local advantage. In the present work, three studies have been carried out using a Matching-to-Sample procedure in order to clarify the conditions under which global or local advantage occurs in capuchin monkeys and humans. The first study was addressed to understand the role played by stimulus redundancy on global-local processing. This study proved that both species can benefit from stimulus redundancy in processing hierarchical stimuli. Furthermore, it revealed that capuchins’ local advantage persists when the grouping requirements occur also at local level. The second study was addressed to understand whether or not inducing an attention bias towards either level of stimulus structure can affect global-local processing. Attentional bias was manipulated using tasks where the proportion of trials requiring global or local processing varied between conditions. Monkeys displayed a local advantage in the local-bias condition but a global advantage in the global-bias condition. Humans exhibited an effect of attentional bias on the processing speed of global-local trials across conditions. The third study was addressed to understand the effect of spatial frequencies processing on global-local processing. The first experiment was addressed to clarify which spatial frequencies could be adopted. The second experiment was designed to assess whether attention allocation to different spatial frequencies (high or low) can affect global-local processing. Both species displayed an effect of spatial frequencies processing on global-local processing. However, this effect was confined to local trials only and occurred under different conditions in the two species. Overall, the results of the present work indicate that attention plays a particularly important role in capuchin monkeys’ visual cognition and are discussed in relation to the extent to which they can explain the observed differences between monkeys and humans in their global-local processing.
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Hoffman, Megan L. "Memory for "what", "where", and "when" information by rhesus monkeys (Macaca mulatta) and adult humans." unrestricted, 2007. http://etd.gsu.edu/theses/available/etd-11212007-001917/.
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Thesis (M.A.)--Georgia State University, 2007.Title from file title page. David A. Washburn, committee chair; Eric Vanman, Michael J. Beran, Heather Kleider, committee members. Electronic text (76 p. : col. ill.) : digital, PDF file. Description based on contents viewed Mar. 25, 2008. Includes bibliographical references (p. 71-76).
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Scrbak, Marko. "Methodical Evaluation of Processing-in-Memory Alternatives." Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1505199/.
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In this work, I characterized a series of potential application kernels using a set of architectural and non-architectural metrics, and performed a comparison of four different alternatives for processing-in-memory cores (PIMs): ARM cores, GPGPUs, coarse-grained reconfigurable dataflow (DF-PIM), and a domain specific architecture using SIMD PIM engine consisting of a series of multiply-accumulate circuits (MACs). For each PIM alternative I investigated how performance and energy efficiency changes with respect to a series of system parameters, such as memory bandwidth and latency, number of PIM cores, DVFS states, cache architecture, etc. In addition, I compared the PIM core choices for a subset of applications and discussed how the application characteristics correlate to the achieved performance and energy efficiency. Furthermore, I compared the PIM alternatives to a host-centric solution that uses a traditional server-class CPU core or PIM-like cores acting as host-side accelerators instead of being part of 3D-stacked memories. Such insights can expose the achievable performance limits and shortcomings of certain PIM designs and show sensitivity to a series of system parameters (available memory bandwidth, application latency and bandwidth sensitivity, etc.). In addition, identifying the common application characteristics for PIM kernels provides opportunity to identify similar types of computation patterns in other applications and allows us to create a set of applications which can then be used as benchmarks for evaluating future PIM design alternatives.
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Paradies, Marcus. "Graph Processing in Main-Memory Column Stores." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-224103.
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Evermore, novel and traditional business applications leverage the advantages of a graph data model, such as the offered schema flexibility and an explicit representation of relationships between entities. As a consequence, companies are confronted with the challenge of storing, manipulating, and querying terabytes of graph data for enterprise-critical applications. Although these business applications operate on graph-structured data, they still require direct access to the relational data and typically rely on an RDBMS to keep a single source of truth and access.
Existing solutions performing graph operations on business-critical data either use a combination of SQL and application logic or employ a graph data management system. For the first approach, relying solely on SQL results in poor execution performance caused by the functional mismatch between typical graph operations and the relational algebra. To the worse, graph algorithms expose a tremendous variety in structure and functionality caused by their often domain-specific implementations and therefore can be hardly integrated into a database management system other than with custom coding. Since the majority of these enterprise-critical applications exclusively run on relational DBMSs, employing a specialized system for storing and processing graph data is typically not sensible. Besides the maintenance overhead for keeping the systems in sync, combining graph and relational operations is hard to realize as it requires data transfer across system boundaries.
A basic ingredient of graph queries and algorithms are traversal operations and are a fundamental component of any database management system that aims at storing, manipulating, and querying graph data. Well-established graph traversal algorithms are standalone implementations relying on optimized data structures. The integration of graph traversals as an operator into a database management system requires a tight integration into the existing database environment and a development of new components, such as a graph topology-aware optimizer and accompanying graph statistics, graph-specific secondary index structures to speedup traversals, and an accompanying graph query language.
In this thesis, we introduce and describe GRAPHITE, a hybrid graph-relational data management system. GRAPHITE is a performance-oriented graph data management system as part of an RDBMS allowing to seamlessly combine processing of graph data with relational data in the same system. We propose a columnar storage representation for graph data to leverage the already existing and mature data management and query processing infrastructure of relational database management systems. At the core of GRAPHITE we propose an execution engine solely based on set operations and graph traversals.
Our design is driven by the observation that different graph topologies expose different algorithmic requirements to the design of a graph traversal operator. We derive two graph traversal implementations targeting the most common graph topologies and demonstrate how graph-specific statistics can be leveraged to select the optimal physical traversal operator. To accelerate graph traversals, we devise a set of graph-specific, updateable secondary index structures to improve the performance of vertex neighborhood expansion. Finally, we introduce a domain-specific language with an intuitive programming model to extend graph traversals with custom application logic at runtime. We use the LLVM compiler framework to generate efficient code that tightly integrates the user-specified application logic with our highly optimized built-in graph traversal operators.
Our experimental evaluation shows that GRAPHITE can outperform native graph management systems by several orders of magnitude while providing all the features of an RDBMS, such as transaction support, backup and recovery, security and user management, effectively providing a promising alternative to specialized graph management systems that lack many of these features and require expensive data replication and maintenance processes.
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Truong, Thanh. "Main-Memory Query Processing Utilizing External Indexes." Doctoral thesis, Uppsala universitet, Avdelningen för datalogi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-280374.
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Many applications require storage and indexing of new kinds of data in main-memory, e.g. color histograms, textures, shape features, gene sequences, sensor readings, or financial time series. Even though, many domain index structures were developed, very a few of them are implemented in any database management system (DBMS), usually only B-trees and hash indexes. A major reason is that the manual effort to include a new index implementation in a regular DBMS is very costly and time-consuming because it requires integration with all components of the DBMS kernel. To alleviate this, there are some extensible indexing frameworks. However, they all require re-engineering the index implementations, which is a problem when the index has third-party ownership, when only binary code is available, or simply when the index implementation is complex to re-engineer. Therefore, the DBMS should allow including new index implementations without code changes and performance degradation. Furthermore, for high performance the query processor needs knowledge of how to process queries to utilize plugged-in index. Moreover, it is important that all functionalities of a plugged-in index implementation are correct. The extensible main memory database system (MMDB) Mexima (Main-memory External Index Manager) addresses these challenges. It enables transparent plugging in main-memory index implementations without code changes. Index specific rewrite rules transform complex queries to utilize the indexes. Automatic test procedures validate the correctness of them based on user provided index meta-data. Moreover, the same optimization framework can also optimize complex queries sent to a back-end DBMS by exposing hidden indexes for its query optimizer. Altogether, Mexima is a complete and extensible platform for transparently index integration, utilization, and evaluation.
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Bloomstrand, Mollie Anne. "An analysis of learning and memory in two aged chimpanzees." Thesis, Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/28573.
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Choi, David Suho. "Integration of non-volatile memory with volatile memory for embedded memory architectures and signal processing applications." Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1692120591&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
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Stutts, William A. (William Anderson). "The Role of Neuronal Histamine in Memory Processing." Thesis, University of North Texas, 1995. https://digital.library.unt.edu/ark:/67531/metadc278349/.
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Neuronal histamine(HA) may play a role in memory processing. This hypothesis is based upon evidence that the action of histamine at central H1 and H2 histamine receptor sites has been shown to modulate memory of rats and mice in adversely-motivated tasks. The purpose of this study was to test this hypothesis more thoroughly in mice using two distinct approaches to neuronal HA manipulation. One approach involved the use of new pharmacological agents which act at the histamine H3 receptor. It has been demonstrated that the selective H3 antagonist thioperamide increases HA release in the brain of mice whereas the H3 agonist imetit decreases HA release via modulation of presynaptic H3 autoreceptors. It was expected that an increase in neuronal HA via the autoreceptor mechanism would result in facilitation of memory processing whereas a decrease in HA release would disrupt memory processing. The second approach involved the manipulation of cerebral HA levels via the specific enzyme inhibiting compounds alpha-flouromethylhistidine (alpha-FMH), a potent neuronal HA depleter and metoprine, a histamine-methyl transferase inhibitor which results in accumulation of neuronal HA. Again, effects of increased HA due to metoprine and decreased HA levels due to alpha-FMH were expected to facilitate and disrupt memory processing respectively. One trial inhibitory (passive) avoidance training was employed in each experiment in order to evaluate the effect of each drug on memory. Each compound was tested for effects on memory consolidation and memory retrieval as well as for the presence of state dependent effects. The pattern of effects obtained with thioperamide suggested facilitation of acquisition or memory storage (consolidation) processes, with no effect on the retrieval phase of memory processing. In accordance with those findings, significant disruption of memory occurred when imetit was present during the consolidation phase of memory processing, but not when presented prior to the retrieval phase. These findings suggest that H3 receptor sites play a significant role in the modulation of memory processes via some mechanism which exclusively affects the acquisition or memory consolidation process, while the retrieval of previously laid down memory traces is unaffected.
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Oliveira, Junior Geraldo Francisco de. "A generic processing in memory cycle accurate simulator under hybrid memory cube architecture." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/170019.
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PIM - uma técnica onde elementos computacionais são adicionados perto, ou idealmente, dentro de dispositivos de memória - foi uma das tentativas criadas durante os anos 1990 visando mitigar o notório memory wall problem. Hoje em dia, com o amadurecimento do processo de integração 3D, um novo horizonte para novas arquiteturas PIM pode ser explorado. Para investigar este novo cenário, pesquisadores dependem de simuladores em software para navegar pelo espaço de exploração de projeto. Hoje, a maioria dos trabalhos que focam em PIM, implementam simuladores locais para realizar seus experimentos. Porém, esta metodologia pode reduzir a produtividade e reprodutibilidade. Neste trabalho, nós mostramos o desenvolvimento de um simulador de PIM preciso, modular e parametrizável. Nosso simulador, chamado CLAPPS, visa a arquitetura de memória HMC, uma memória 3D popular, que é amplamente utilizada em aceleradores PIM do estado da arte. Nós desenvolvemos nosso mecanismo utilizando a linguagem de programação SystemC, o que permite uma simulação paralela nativamente. A principal contribuição do nosso trabalho se baseia em desenvolver a interface amigável que permite a fácil exploração de arquiteturas PIM. Para avaliar o nosso sistema, nós implementamos um modulo de PIM que pode executar operações vetoriais com diferente tamanhos de operandos utilizando o proposto conjunto de ferramentas.PIM - a technique which computational elements are added close, or ideally, inside memory devices - was one of the attempts created during the 1990s to try to mitigate the memory wall problem. Nowadays, with the maturation of 3D integration technologies, a new landscape for novel PIM architectures can be investigated. To exploit this new scenario, researchers rely on software simulators to navigate throughout the design evaluation space. Today, most of the works targeting PIM implement in-house simulators to perform their experiments. However, this methodology might hurt overall productivity, while it might also preclude replicability. In this work, we showed the development of a precise, modular and parametrized PIM simulation environment. Our simulator, named CLAPPS, targets the HMC architecture, a popular 3D-stacked memory widely employed in state-of-the-art PIM accelerators. We have designed our mechanism using the SystemC programming language, which allows native parallel simulation. The primary contribution of our work lies in developing a user-friendly interface to allow easy PIM architectures exploitation. To evaluate our system, we have implemented a PIM module that can perform vector operations with different operand sizes using the proposed set of tools.
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Kester, Jill Darcy. "Reduced processing resources, organization, elaboration and memory performance." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0028/MQ40685.pdf.
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Lam, Wai-yan Sabena, and 林緯欣. "Cantonese relative clause processing: a working memory study." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B50534142.
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The processing of relative clauses has been a subject of recurrent interest in psycholinguistics. While a consistent processing preference for subject relative clauses has been found in English (e.g. Just & Carpenter, 1992; King & Just, 1991; King & Kutas, 1995; Traxler, Morris, & Seely, 2002), studies in Mandarin Chinese have not yielded consistent results in the processing asymmetry between subject and object relative clauses (e.g. Hsiao & Gibson, 2003; Lin, 2006). On the other hand, human cognitive preferences have been found to play a role in parsing (Gibson & Pearlmutter, 1998; Tanenhaus & Trueswell, 1995). This dissertation is interested in relating memory with syntactic structures in the course of syntactic parsing, in the hope that it could resolve the conflicting findings in Chinese. We address this by studying Cantonese relative clauses from a processing and working memory perspective. Two experiments were carried out. Experiment 1 involved a self-paced reading task together with an n-back memory task. We found some evidence, although not very conclusive, that object relative clauses were more difficult to comprehend, as reflected in poor comprehension accuracy and response latency. There was significant memory intervention in reading times, though its role in syntactic processing was not clear. Experiment 2 reported a maze task together with an n-back memory task. A processing disadvantage for object relative clauses was evident from a significantly longer reading time on a whole and in the post-relative clause region. A memory effect was found only at the post-relative clause region, possibly indicating that memory capacity as measure by n-back was not influencing the syntactic processing of relative clauses. This dissertation addresses a heavy task effect between Experiment 1 and 2, and the possible discrepancy between processing performance and production preferences. Processing models emphasizing the role of memory and syntactic structures as well as the “cooperation” of the two models were also discussed.published_or_final_version
Linguistics
Master
Master of Philosophy
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Koutmeridou, Kyriaki. "Memory as discrimination : strategic processing of retrieval cues." Thesis, City University London, 2013. http://openaccess.city.ac.uk/2982/.
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This thesis investigates the validity of a memory retrieval view that insists on the diagnostic relationship between retrieval cues and target memories and examines how the diagnostic value of a cue can influence the processing it receives. As a concept, the encoding-retrieval match is a widely accepted explanation of retrieval performance. According to this view, performance relates to the overlap between the retrieval information and the to-be-recalled information [see Tulving (1979, 1983) for a discussion]. The cue overload effect is another well-established phenomenon. It stipulates that retrieval performance will decrease as the number of potential targets in memory subsumed under a retrieval cue increases (Watkins & Watkins, 1975). Assuming these two factors can interact, a variety of outcomes are possible. The memory-as-discrimination view, investigated as part of this thesis, suggests that factors such as cue overload, distinctiveness, and potentially others contribute to a process of memory retrieval where diagnosticity is central (Nairne, 2002). Under such a system, retrieval is most likely to be successful when a cue specifies a target in memory to the exclusion of other potential candidates. In the second chapter, this idea is tested via three studies that use a cued-recognition paradigm. Results support the memory-as-discrimination view. However, this set of experiments brought to light another interesting phenomenon: participants appeared to prioritise the processing of the more diagnostic cues, perhaps in an effort to maximise the discrimination power of the available cue constellations. Support for this hypothesis is provided in the third chapter through a set of three experiments calling upon eye-tracking and other measures. Results from all three studies suggest that people preferentially process the more discriminative cues. How well a cue specifies a retrieval target appears to have two related effects: diagnosticity has a causal relationship with retrieval performance and it determines which cues are prioritised / processed with more emphasis.
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St, Aubyn Michael. "Connectionist rule processing using recursive auto-associative memory." Thesis, University of Hertfordshire, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269445.
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McLean, Jennifer E. "Processing capacity of visual perception and memory encoding /." Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/9019.
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Sprenger, Stefan. "Efficient Processing of Range Queries in Main Memory." Doctoral thesis, Humboldt-Universität zu Berlin, 2019. http://dx.doi.org/10.18452/19786.
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Datenbanksysteme verwenden Indexstrukturen, um Suchanfragen zu beschleunigen. Im Laufe der letzten Jahre haben Forscher verschiedene Ansätze zur Indexierung von Datenbanktabellen im Hauptspeicher entworfen. Hauptspeicherindexstrukturen versuchen möglichst häufig Daten zu verwenden, die bereits im Zwischenspeicher der CPU vorrätig sind, anstatt, wie bei traditionellen Datenbanksystemen, die Zugriffe auf den externen Speicher zu optimieren. Die meisten vorgeschlagenen Indexstrukturen für den Hauptspeicher beschränken sich jedoch auf Punktabfragen und vernachlässigen die ebenso wichtigen Bereichsabfragen, die in zahlreichen Anwendungen, wie in der Analyse von Genomdaten, Sensornetzwerken, oder analytischen Datenbanksystemen, zum Einsatz kommen.
Diese Dissertation verfolgt als Hauptziel die Fähigkeiten von modernen Hauptspeicherdatenbanksystemen im Ausführen von Bereichsabfragen zu verbessern. Dazu schlagen wir zunächst die Cache-Sensitive Skip List, eine neue aktualisierbare Hauptspeicherindexstruktur, vor, die für die Zwischenspeicher moderner Prozessoren optimiert ist und das Ausführen von Bereichsabfragen auf einzelnen Datenbankspalten ermöglicht. Im zweiten Abschnitt analysieren wir die Performanz von multidimensionalen Bereichsabfragen auf modernen Serverarchitekturen, bei denen Daten im Hauptspeicher hinterlegt sind und Prozessoren über SIMD-Instruktionen und Multithreading verfügen. Um die Relevanz unserer Experimente für praktische Anwendungen zu erhöhen, schlagen wir zudem einen realistischen Benchmark für multidimensionale Bereichsabfragen vor, der auf echten Genomdaten ausgeführt wird. Im letzten Abschnitt der Dissertation präsentieren wir den BB-Tree als neue, hochperformante und speichereffziente Hauptspeicherindexstruktur. Der BB-Tree ermöglicht das Ausführen von multidimensionalen Bereichs- und Punktabfragen und verfügt über einen parallelen Suchoperator, der mehrere Threads verwenden kann, um die Performanz von Suchanfragen zu erhöhen.Database systems employ index structures as means to accelerate search queries. Over the last years, the research community has proposed many different in-memory approaches that optimize cache misses instead of disk I/O, as opposed to disk-based systems, and make use of the grown parallel capabilities of modern CPUs. However, these techniques mainly focus on single-key lookups, but neglect equally important range queries. Range queries are an ubiquitous operator in data management commonly used in numerous domains, such as genomic analysis, sensor networks, or online analytical processing. The main goal of this dissertation is thus to improve the capabilities of main-memory database systems with regard to executing range queries. To this end, we first propose a cache-optimized, updateable main-memory index structure, the cache-sensitive skip list, which targets the execution of range queries on single database columns. Second, we study the performance of multidimensional range queries on modern hardware, where data are stored in main memory and processors support SIMD instructions and multi-threading. We re-evaluate a previous rule of thumb suggesting that, on disk-based systems, scans outperform index structures for selectivities of approximately 15-20% or more. To increase the practical relevance of our analysis, we also contribute a novel benchmark consisting of several realistic multidimensional range queries applied to real- world genomic data. Third, based on the outcomes of our experimental analysis, we devise a novel, fast and space-effcient, main-memory based index structure, the BB- Tree, which supports multidimensional range and point queries and provides a parallel search operator that leverages the multi-threading capabilities of modern CPUs.
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Cahn, Janet E. (Janet Elizabeth). "A computational memory and processing model for prosody." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/29142.
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Thesis (Ph.D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts & Sciences, 1999.Includes bibliographical references (p. 209-226).
This thesis links processing in working memory to prosody in speech, and links different working memory capacities to different prosodic styles. It provides a causal account of prosodic differences and an architecture for reproducing them in synthesized speech. The implemented system mediates text-based information through a model of attention and working memory. The main simulation parameter of the memory model quantifies recall. Changing its value changes what counts as given and new information in a text, and therefore determines the intonation with which the text is uttered. Other aspects of search and storage in the memory model are mapped to the remainder of the continuous and categorical features of pitch and timing, producing prosody in three different styles: for small recall values, the exaggerated and sing-song melodies of children's speech; for mid-range values, an adult expressive style; for the largest values, the prosody of a speaker who is familiar with the text, and at times sounds bored or irritated. In addition, because the storage procedure is stochastic, the prosody from simulation to simulation varies, even for identical control parameters. As with with human speech, no two renditions are alike. Informal feedback indicates that the stylistic differences are recognizable and that the prosody is improved over current offerings. A comparison with natural data shows clear and predictable trends although not at significance. However, a comparison within the natural data also did not produce results at significance. One practical contribution of this work is a text mark-up schema consisting of relational annotations to grammatical structures. Another is the product - varied and plausible prosody in synthesized speech. The main theoretical contribution is to show that resource-bound cognitive activity has prosodic correlates, thus providing a rationale for the individual and stylistic differences in melody and rhythm that are ubiquitous in human speech.
by Janet Elizabeth Cahn.
Ph.D.
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Shelor, Charles F. "Dataflow Processing in Memory Achieves Significant Energy Efficiency." Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1248478/.
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The large difference between processor CPU cycle time and memory access time, often referred to as the memory wall, severely limits the performance of streaming applications. Some data centers have shown servers being idle three out of four clocks. High performance instruction sequenced systems are not energy efficient. The execute stage of even simple pipeline processors only use 9% of the pipeline's total energy. A hybrid dataflow system within a memory module is shown to have 7.2 times the performance with 368 times better energy efficiency than an Intel Xeon server processor on the analyzed benchmarks.
The dataflow implementation exploits the inherent parallelism and pipelining of the application to improve performance without the overhead functions of caching, instruction fetch, instruction decode, instruction scheduling, reorder buffers, and speculative execution used by high performance out-of-order processors. Coarse grain reconfigurable logic in an energy efficient silicon process provides flexibility to implement multiple algorithms in a low energy solution. Integrating the logic within a 3D stacked memory module provides lower latency and higher bandwidth access to memory while operating independently from the host system processor.
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Chan, Xinni. "Survival Processing Effect on Memory for Social Information." University of Toledo / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1490710246565186.
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Grilli, Matthew Dennis. "Self-Imagining, Recognition Memory, and Prospective Memory in Memory-Impaired Individuals with Neurological Damage." Thesis, The University of Arizona, 2009. http://hdl.handle.net/10150/193396.
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The present study investigated the reliability and robustness of a new mnemonic strategy - self-imagination - in a group of memory-impaired individuals with neurological damage. Despite severe memory deficits, almost all of the participants demonstrated a self-imagination effect (SIE) for recognition memory in study 1. Moreover, the ability to benefit from self-imagination was not affected by the severity of the memory deficit. In study 3, more than half of the participants showed a SIE on a task of event-based prospective memory. The data from study 2 suggest the SIE is not attributable to semantic processing or emotional processing and indicate that self-imagination is distinct from other mnemonic strategies. Overall the findings from the present study implicate self-imagination as a new and effective mnemonic strategy. The data also indicate that when it comes to memory there is something special about processing information in relation to the self.
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Ikei, Mitsuru. "Automatic program restructuring for distributed memory multicomputers." Full text open access at:, 1992. http://content.ohsu.edu/u?/etd,191.
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He, Bingsheng. "Cache-oblivious query processing /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?CSED%202008%20HE.
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Brock, Jonathan Peter. "Language and memory in Williams sydrome." Thesis, University of Warwick, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250086.
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Bellew, Margaret. "Information processing biases and depression." Thesis, Keele University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292746.
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Akande, Rachel Sarah. "Autobiographical memory and depression : an investigation of over general memory processing on recall tasks." Thesis, University of Hertfordshire, 2004. http://hdl.handle.net/2299/14250.
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Depression is a prevalent diagnosis within psychiatric populations. People with depression have been shown to recall over general autobiographical memories. The current study uses a cognitive stage model of memory to explain the retrieval processes involved in autobiographical memory. Two memory tasks were used: a standard cued recall task and a free recall cued task. Thirty individuals participated in the study: 15 clinically depressed individuals and 15 non-depressed controls. Analysis showed that the depressed group were significantly more over general than the comparison group. The free recall task provided data on the processes involved in retrieving a specific memory. The depressed group were observed to experience an aberration in this process. Further, they were less able to navigate around the autobiographical memory network. Large effect sizes were found between the groups. The implications of these findings in terms of self concept and difficulties problem solving are discussed. In addition, the consequences for assessment, diagnosis, treatment and relapse are explored. Recommendations for future research are made.
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Morris, Frank William. "Parallax (memory as a torn page)." Virtual Press, 1985. http://liblink.bsu.edu/uhtbin/catkey/491451.
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The purpose of this creative project was to explore the possibilities of words and photographic images in expressing mood. The particular mood that was to be expressed came from the observation of small rituals. These small rituals are an avenue that humans tend to derive meaning and continuity. Beyond this, the use of the Platinum/ Palladium photographic process as an expressive tool was examined.
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Argile, Andrew Duncan Stuart. "Distributed processing in decision support systems." Thesis, Nottingham Trent University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259647.
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Leung, Wing-in, and 梁穎妍. "The relationship between specific memory recall and future event processing." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/209549.
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The present study aims at examining the relationship between specific memory recall and future event processing. Previous research suggested that the ability in generating specific future events was closely linked with recalling specific past memories. A total of 73 participants (40 in depressed group and 33 healthy control group) completed a specific memory recall and a future event generation task with emotional cues (positive and negative) and a neutral cue. The number of specific responses generated and the mean specific memory latency were recorded for analysis. Result not only replicated previous findings that the depressed group demonstrated more difficulties in generating specific responses, it also provided new insight in exploring the relationship between specific memory recall and future events processing. Firstly, the result indicated that the number of specific responses was fewer and the mean latency of specific responses was longer in generating future events than recalling specific memories. Secondly, the number and the mean latency of specific responses depended on different emotional loaded cues. Further discussion was focused on the valence effect on specific responses. Lastly, it was revealed that depressed patients had a particular difficulty in generating positive future events. Discussion was emphasized on the emotional loaded effect and hopelessness. Both theoretical and clinical implicated were suggested based on the new findings.published_or_final_version
Clinical Psychology
Master
Master of Social Sciences
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Nakabayashi, Kazuyo. "The role of verbal processing in face recognition memory." Thesis, University of Glasgow, 2005. http://theses.gla.ac.uk/1268/.
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This dissertation attempts to provide a comprehensive view of the role of verbal processing in face recognition memory by examining some of the neglected issues in two streams of cognitive research, face recognition and verbal overshadowing. Traditionally, research in face recognition focuses on visual and semantic aspects of familiar and unfamiliar face processing, with little acknowledgement of any verbal aspect. By contrast, the verbal overshadowing literature examines the effect of verbal retrieval of unfamiliar face memory on subsequent recognition, with little attention to actual mechanisms underlying processing of these faces. Although both are concerned with our ability to recognise faces, they have proceeded independently as their research focus is diverse. It therefore remains uncertain whether or not face encoding entails verbal processing, and whether or not verbal processing is always detrimental to face recognition. To address these issues, some experimental techniques used in face recognition research were combined with methods from verbal overshadowing research. The first strand of experiments examined configural-visual and featural-verbal processing associations in change recognition tasks. The second strand systematically examined the role of verbal processing in recognition memory by manipulating the degree of verbal involvement during and after encoding. The third strand examined the ‘perceptual expertise’ account of verbal overshadowing in picture recognition memory tasks, involving pictures of familiar and unfamiliar people. The fourth strand directly tested a tentative hypothesis ‘verbal code interference’ to explain verbal overshadowing by manipulating the frequency and time of face verbalisation in line-up identification tasks. The concluding experiment looked at the relation between intentional learning and verbal overshadowing in a recognition memory task using more naturalistic stimuli. The main findings indicate first, that mechanisms underlying face processing appear to be complex, and simple processing associations (configural-visual and featural-verbal processing) cannot be made. Second, face encoding seems to involve some sort of verbal processing which may actually be necessary for successful recognition. Third, post-encoding verbalisation per se does not seem to be the key determiner for recognition impairment. Rather, the interference between verbal representations formed under different contexts seems to harm recognition. Fourth, verbal overshadowing was found only for unfamiliar face picture recognition, but not for familiar face picture recognition, casting a doubt on ‘perceptual expertise account’. Finally, although no clear evidence linking intentional learning and verbal overshadowing was found, intentional learning and verbalisation in combination affected a response pattern. These results were discussed in relation to ongoing debate over causes of the verbal overshadowing effect, which raises an important ecological question as to whether the phenomenon might reflect natural human memory interference.
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Vasishth, Shravan. "Working Memory in Sentence Comprehension: Processing Hindi Center Embeddings." Connect to this title online, 2002. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1023402958.
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Thesis (Ph. D.)--Ohio State University, 2002.Title from first page of PDF file. Document formatted into pages; contains xxiii, 252 p.; also includes graphics. Includes abstract and vita. Advisor: Shari Speer, Dept. of Linguistics; Richard Lewis, Dept. of Psychology, University of Michigan. Includes bibliographical references (p. 240-252).
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Heithecker, Sven. "Communication and memory scheduling in reconfigurable image processing systems." Berlin Dissertation.de, 2008. http://d-nb.info/994809271/04.
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Conlin, Juliet Ann. "The relationship between storage and processing in working memory." Thesis, Durham University, 2005. http://etheses.dur.ac.uk/1787/.
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Mance, Irida. "The Contribution of Alpha Oscillations to Working Memory Processing." Thesis, University of Oregon, 2015. http://hdl.handle.net/1794/19226.
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Working memory, which enables the temporary storage of information in an active “online” state, is an exceptionally capacity limited system. Given this capacity limit, irrelevant information in our environment must be filtered out, while relevant representation is maintained. Research has shown that neural oscillations in the alpha frequency range (8-12Hz) are greatly influenced by the number of items in memory. Most work has argued that alpha oscillations primarily support working memory processing by suppressing information that could interfere with items already in memory, as indexed by an increase in alpha power. However, other work has shown that decreases in alpha power, with little evidence of concurrent increases, support the maintenance of working memory representations.
In this thesis we show that, in the context of visual working memory, the primary role of alpha oscillations is to maintain distinct working memory representations, rather than to suppress irrelevant information. This is shown in a series of three experiments all indicating that as the number of relevant items increases, the power of alpha oscillations systematically decreases. In the first experiment, we use a whole report and change detection task to examine how the number of items in memory influences alpha oscillations. In the second experiment, we use a cuing (Experiment 2A) and filtering (Experiment 2B) paradigm to demonstrate that alpha power tracks the number of remembered items instead of the number of total items on the screen. Lastly, by presenting items sequentially (Experiment 3A) or in overlapping locations (Experiment 3B), we see evidence that decreases in alpha power are related to the maintenance of relevant spatial locations, instead of the number of items in memory. The results of the experiments suggest that alpha power reflects the maintenance of relevant working memory representations, rather than the suppression of irrelevant external distractors or the inhibition of task-irrelevant neural areas. Furthermore, our last experiment indicates that the alpha frequency band is especially sensitive to the maintenance of spatial information.
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Wildegger, Theresa. "Biases in information processing across perception and working memory." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:4efcef9a-46fc-4187-ac96-9708b688a80f.
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Research over the last decades has demonstrated an enormous flexibility of attentional mechanisms in the human brain and has revealed many forms of biases across perception and working memory. In this thesis, I extend our knowledge of the flexible role of attention, and ways in which information processing can be biased to guide perception and working memory (WM). In the General Introduction, I review perceptual, WM and attention literature to describe our current understanding of the many biases across different stages of information processing. In Chapter 2, I present a study that uses functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) to contrast and compare neural mechanisms supporting spatial and feature-based attentional selection. Neural signatures of preparatory attention revealed that comparable neural mechanisms support both kinds of attention. However, brain activity is modulated relatively more globally for feature-based compared to spatial attention, consistent with representational differences between feature and spatial information. In Chapter 3, I describe four Experiments exploring the impact of incoming sensory information, presented supraliminally or subliminally, on performance in a WM task and a visuomotor priming task. While both subliminal and supraliminal information shaped performance in the visuomotor priming task, WM representations appeared to be protected against subliminal influences and performance was only affected by information presented supraliminally. In Chapter 4, I present three Experiments that examine how bottom-up stimulus differences during encoding modulate top-down attentional effects in WM. The results reveal that benefits of retrospective attentional selection in WM persist regardless of the quality of sensory information, but the underlying mechanisms vary along with changes in stimulus properties during encoding. In Chapter 5, the General Discussion, I place the results of this work in their wider context, and discuss limitations and future directions.
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Blankenship, Tashauna L. "Episodic Memory during Middle Childhood: Active vs. Passive Processing." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/78120.
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Episodic memory refers to context based explicit memory and shows vast improvements during middle childhood. In this study, episodic encoding was manipulated using stimuli that were hypothesized to require active or passive processing. Nine to eleven-year-old children were presented with a recall task using lower resolution (active processing) and clear (passive processing) images. It was hypothesized that children would recall more low resolution images than clear images. Executive function ability was also assessed to investigate possible contributions to performance. Furthermore, this study investigated whether frontal and temporal brain electrophysiology predicted unique variance in recall performance. Results suggested that overall there were no performance differences between low resolution and clear images; however, differences may exist within task blocks. Electrophysiology at temporal scalp locations and executive functions predicted unique variance in memory task performance. Specifically, set-shifting and working memory predicted a unique amount of variance in memory task performance. The results suggest that explicit memory may require certain executive processes more than others, and that active and passive processing may enhance this effect.Master of Science
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Fathi, Salmi Meisam. "Processing Big Data in Main Memory and on GPU." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1451992820.
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Kaplan, R. S. M. "Brain oscillations and novelty processing in human spatial memory." Thesis, University College London (University of London), 2013. http://discovery.ucl.ac.uk/1399842/.
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Hippocampal activity in rodent model systems is commonly associated with movement and exploratory behaviour, while human hippocampal research has traditionally focused on mnemonic function. I attempted to bridge this gap with a set of experiments where human participants performed an interactive virtual navigation paradigm that resembled rodent spatial exploration tasks, in conjunction with neuroimaging techniques such as functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG). I then used this interactive paradigm to examine the oscillatory correlates of memory, novelty and the behavioural relevance of the default mode network. The first experiment used MEG and fMRI to examine whether the movement-related theta rhythm (4-8 Hz) recorded from the rodent hippocampus has a measurable human analog. I found that the human hippocampal theta rhythm supports memory, and may coordinate exploratory movements in the service of self-directed learning. In further analyses in Experiment 2, during cued spatial memory retrieval, I observed that medial prefrontal cortex theta phase couples with ongoing theta oscillations in the right anterior medial temporal lobe and with neocortical gamma (65-85 Hz) amplitude. In Experiment 3, with fMRI I investigated the effect of environmental novelty versus object novelty during the navigation task and found that hippocampal activity is modulated only by environmental novelty, while the fusiform gyrus/posterior parahippocampal cortex responded to object novelty. Finally, in Experiment 4 using 3T and high-field 7T fMRI, I investigated endogenous (task-free) periods that flanked different stages of a spatial navigation paradigm to determine how endogenous slow oscillations in the default mode network correlate with subsequent spatial memory performance and found mixed evidence that default mode network activity predicts individual performance. Finally, I discuss my results in the context of recent findings in spatial memory and novelty processing, and consider the relationship between the human hippocampus and rodent model systems.