A dual-task paradigm was used to infer the processes critical for episodic memory retrieval by measuring susceptibility to memory interference from different distracting tasks. Research suggests that retrieval interference occurs due to material-specific overlap between concurrent tasks. I tested whether interference could instead arise from processing-specific overlap. In Experiment 1, I took advantage of individual differences in how verbal materials could be represented in those with different language backgrounds. I compared recognition of studied information in English and Chinese speakers under full attention (FA) or under one of two different divided attention (DA) conditions. Participants viewed simplified Chinese characters or English words, and later completed recognition while simultaneously performing distracting tasks requiring phonological (DAP) or visuospatial (DAV) processing of auditorily presented letters. I found an interaction such that Chinese speakers were more susceptible to interference from the visuospatial than phonological distracting task, whereas the reverse pattern was shown in English speakers. These results suggest that interference with memory retrieval is processing-, not material-, specific, as both distracting tasks used the same materials. Next I sought to determine whether processing-specific interference could be observed within the visuo-spatial domain. Accordingly, in Experiments 2 and 3, I examined whether face recognition would be disrupted more by a distracting task requiring configural than featural processing. In Experiment 2, participants studied faces under FA and subsequently performed a recognition task under either FA or each of two different DA conditions in which a distracting face was presented alongside, requiring either a featural (DAF) or configural (DAC) decision. In line with a material-specific account of interference, face memory accuracy was disrupted in both DA conditions relative to the FA condition, although no processing-specific differences in interference were found between the DA conditions, likely because both distracting tasks engaged configural processing. To better isolate the different processing streams in Experiment 3, some faces were inverted to offset configural processing and to engage featural processing. I compared patterns of memory interference when target faces were presented upright (configural) or inverted (featural). I found a crossover interaction: memory for upright faces was worse in the DAC than in the DAF condition, whereas the reverse was true for inverted target faces, supporting a processing-specific account of memory interference. In Experiment 4, I sought to rule out task difficulty as an alternative explanation for the pattern of interference effects. I measured whether each distracting task produced similar slowing, which provides an indirect assessment of resource requirements of a task, on a simultaneously performed auditory tone discrimination task. Results showed that my distracting tasks were not differentially attention demanding, as indexed by similar accuracy rates for tone classification and response times on the tone discrimination task when performed concurrently with each distracting task. Findings suggest that the magnitude of memory interference under DA conditions at retrieval is influenced by material-specificity but that, critically, it also depends on the extent to which the processing demands of the distracting and retrieval tasks overlap. I have shown here that retrieval is not automatic or obligatory as others have suggested, but instead is subject to disruption. This thesis specifies that retrieval interference can occur due to competition for a limited pool of common processing resources across target and distracting tasks. Thus, when trying to recall studied information, one should avoid distracting conditions, especially those that overlap significantly not only with the type of materials tested but also with the mental processes required to retrieve that target information.

No description available.

No description available.

No description available.

No description available.

In memory, encoding and retrieval are often conceived of as two separate processes. However, there is substantial evidence to suggest that this view is wrong—that they are instead highly interdependent processes. One recent example is from Jacoby, Shimizu, Daniels, and Rhodes (2005a), who showed that new words presented as foils among a list of old words that had been deeply encoded were themselves subsequently better recognized than were new words presented as foils among a list of old words that had been shallowly encoded. This paradigm, referred to as memory-for-foils, not only demonstrates a link between encoding and retrieval, but also has led to a proposal about what form this interaction is taking in this task. Jacoby et al. (2005a) proposed that people put in place a retrieval mode that leads to a reprocessing of the original encoding state, which is incidentally applied across both old and new items within the context of a recognition memory test. Such a constrained-retrieval account suggests an intimate relation between encoding and retrieval processes that allows for memories to be highly integrated. The goal of this thesis is to provide a better understanding of the generalizability and limitations of this memory-for-foils phenomenon and, ultimately, to provide more direct evidence for the interaction of these processes. Experiments 1 and 2 began by replicating the memory-for-foils phenomenon as well as an experiment by Marsh et al. (2009b) which confirmed that the phenomenon does not result simply from strength of encoding differences. Experiment 3 then substituted a deep vs shallow imagery manipulation for the levels-of-processing manipulation, demonstrating that the effect is robust and that it generalizes, also occurring with a different type of encoding. Experiment 4 extended the generalizability of the task to factual phrases. Experiment 5 then moved on to testing the encoding/retrieval interactions by once again employing the imagery encoding manipulation with an additional quality judgment in the final recognition memory test. Using the remember/know paradigm (Gardiner, 1988; Tulving, 1985) demonstrated that more highly-detailed memories were associated with foils from the test of deep items than with foils from the test of shallow items. From there, response time was used to infer processing speed in Experiment 6a, in a test of whether foils tested among deep items incur an advantage independent of the manipulation undergone by those items. When a lexical decision test replaced the final recognition test, there was no evidence of a memory advantage for “deep” foils over “shallow” foils. Finally, Experiment 6b provided compelling evidence for context-related encoding during tests of deeply encoded words, showing enhanced priming for foils presented among deeply encoded targets when participants made the same deep encoding judgments on those items as were made on the targets during study. Taken together, these findings provide support for the source-constrained retrieval hypothesis and for the idea of a retrieval mode. New information—information that we may not even be intending to remember— is influenced by how surrounding items are encoded and retrieved, as long as the surrounding items recruit a coherent mode of processing. This demonstrates a clear need to consider encoding and retrieval as highly interactive processes and to avoid conceptualizing them as entirely separate entities. This is a crucial part of increasing our understanding of the fundamental processes in memory.

With the increasing usage of storing textual data into relational databases, there is a demand for the databases to support keyword queries over textual data. Due to the normalization and the inherent connections among tuples in different tables, traditional IR-style ranking and query evaluation methods do not apply. A number of systems have been proposed to deal with this issue. In this thesis, I will give a detailed demonstration and description to our SPARK project. In the project, we study both the effectiveness and the efficiency issues of answering top-k keyword query on a relational database system. We propose a new ranking formula by adapting existing IR techniques on a natural notion of ???virtual document???. Compared with previous approaches, our new ranking method is simple yet effective, and agrees with human being???s perception better. We also study efficient query processing methods based on the new ranking method, and propose algorithms that have minimal accesses to the database. We have conducted extensive experiments on large-scale real databases using two popular RDBMSs. The experimental results demonstrate significant improvement to the alternative approaches in terms of both retrieval effectiveness and efficiency. We build a prototype of SPARK system on top of popular RDBMS based on these new techniques to satisfy different kinds of users and to support various query modes.

151 [47] leaves : ill. ; 26 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.1972) from the Dept. of Electrical Engineering, University of Adelaide

[Abstract]: This work involves the development of a lightweight, high efficiency, integrated Neonatal Retrieval System consistent with the requirements of medical personnel, with the capability to be loaded into ambulance vehicles without lifting.By studying the current systems in use and surveying the potential end users a basic specification is established. From this specification concepts are cultivated and, withregular input from end users, developed into a working prototype. This prototype is tested to the required standards and assessed by the end users. Following positivefeedback, a clinical trial is undertaken by medical personnel who confirm that the new system addresses many of the operational problems encountered with currentequipment.It is concluded that with further refinement and sufficient commercial backing, this new Neonatal Retrieval System would improve the process of neonatal retrieval inthis country and possibly internationally. This has the potential to improve outcomes for both patients and the medical personnel who conduct these retrievals.

Zugl.: Saarbrücken, Univ., Diplomarbeit, 2003 u.d.T.: Wirschum, Nadine: Erleichterung der Informationssuche im Internet