Thesis (doctoral)--Universität Hamburg.

Thesis (doctoral)--Unviersität Hamburg.

Thesis (M.A.)--University of Missouri-Columbia, 2008. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 19, 2009) Includes bibliographical references.

Research into the nature and content of visual long-term memory has investigated what aspects of its representation may account for the remarkable ability we have to remember large amounts of detailed visual information. One theory proposed is that visual memories are supported by an underlying structure of conceptual knowledge around which visual information is organized. However, findings in memory for visual information learned in a visual search task were not explained by this theory of conceptual support, and a new theory is proposed that incorporates the importance of episodic, task-relevant visual information into the organizational structure of visual memory. The current study examined visual long-term memory organization as evidenced by retroactive interference effects in memory for objects learned in a visual search. Four experiments were conducted to examine the amount of retroactive interference induced based on aspects in which interfering objects were related to learned objects. Specifically, episodically task-relevant information about objects was manipulated between conditions based on search instructions. Aspects of conceptual category, perceptual information (color), and context (object role in search) were examined for their contribution to retroactive interference for learned objects. Findings indicated that when made episodically task-relevant, perceptual, as well as conceptual, information contributed to the organization of visual long-term memory. However, when made episodically non-relevant, perceptual information did not contribute to memory organization, and memory defaulted to conceptual category organization. This finding supports the theory of an episodically defined organizational structure in visual long-term memory that is overlaid upon an underlying conceptual structure.

Fornecer dicas durante o período de manutenção de estímulos em tarefas de memória de trabalho melhora o desempenho dos participantes tanto para a acurácia quanto para o tempo de resposta (TR). Esse fenômeno é chamado de efeito de dicas retroativas. Nós realizamos três experimentos usando uma tarefa de reconhecimento de itens para testar a suposição de que o efeito das dicas retroativas é dependente de uma representação imagética disponível à inspeção consciente no momento da apresentação da dica. No Experimento 1, nós manipulamos o tamanho do conjunto (2 e 3 itens) a ser memorizado e inserimos uma tarefa de busca visual no intervalo de retenção para evitar a recitação visual dos estímulos. Nós aplicamos o método dos fatores aditivos de Sternberg para medir o tempo gasto pelos participantes para reativar os itens memorizados na forma de imagens mentais. O intercepto da função linear entre TR e tamanho do conjunto sofreu um incremento de 400 ms na presença da busca visual. No Experimento 2, nós inserimos 500 ms de tela em branco após a tarefa de busca visual e imediatamente antes do aparecimento da dica, para que os participantes usassem esse intervalo para reativar os itens na forma de imagens mentais. O efeito da dica retroativa ocorreu tanto para o TR quanto para o índice de discriminação (d). No Experimento 3, nós manipulamos a natureza da tarefa concorrente durante o intervalo de retenção: busca visual, monitoramento de tons e discriminação de cores. A busca visual foi a mais prejudicial ao desempenho dos participantes e ao efeito da dica retroativa, seguida pela discriminação de cores. A combinação de demanda atencional e necessidade de processamento visual presente na busca visual é especialmente prejudicial ao desempenho. Concluímos que o funcionamento das dicas retroativas é modulado por esses dois fatores, e não só por recursos atencionais centrais. Os resultados apoiam um modelo de memória de trabalho que considera o fenômeno da imaginação mental em sua arquitetura / Providing cues during the maintenance period of working memory tasks improves participants\' performance in terms of accuracy and response times (RT). This phenomenon is known as the retro-cue effect. We performed three experiments to test the assumption that the retro-cue effect relies on an imagetic representation of the stimuli, available to conscious inspection at the moment of the cue\'s onset. In Experiment 1, we manipulated the number of stimuli (set size 2 and 3) and inserted a visual search task during the retention interval to prevent visual rehearsal. We applied the Sternberg\'s additive factors method to measure the time participants spent to reactivate the items under the form of mental images. The intercept of the linear function between RT and set size increased 400 ms in the presence of the visual search. In Experiment 2, we added 500 ms of blank screen after the visual search task and immediately before the cue\'s onset, so that participants could use this interval to reactivate the items as mental images. The retro-cue effect occurred both for the RT and the discrimination index (d\'). In Experiment 3, we manipulated the type of the concurrent task during the retention interval: visual search, tone monitoring, and color discrimination. The visual search was the most deleterious task for the participants\' performance and for the retro-cue effect, followed by the color discrimination. The combination of attentional demand and visual processing in the visual search was particularly deleterious to performance. We concluded that the functioning of retro-cues is modulated by those two factors, and not only by central attentional resources. The results support a working memory model that considers the phenomenon of mental imagery in its architecture

Research has examined how encoding or retrieval factors affect metamemory. Few studies have manipulated both an encoding and a retrieval factor in the same paradigm. The current experiments examined which factor had a greater impact on metamemory when both were manipulated. Attention was manipulated during encoding and Retroactive Interference was manipulated at retrieval.Two lists of word pairs were studied, with the second list including both new pairs and cues from the first list re-paired with a new target. The attention manipulation occurred when studying the first list in which participants denoted when one tone sequence changed to another. Participants gave predictions about the likelihood of future recall of the original targets either immediately following study (JOL) or in a separate phase after studying all pairs (DJOL). The Modified Opposition Test (MOT) was used in which a hint was used to direct participants to the correct list for recall. After all pairs were studied and predicted, participants completed a cued-recall test. In Experiment 1, DJOLs were used because they are collected between encoding and retrieval. Both factors impacted memory, but DJOLs were only impacted by the retrieval factor. A dissociation between memory and metamemory under retroactive interference was expected and replicates prior research (Eakin, 2005). In Experiment 2, JOLs were added; JOLs are measured during the encoding phase, allowing the impact of the encoding factor to be observed. Replicating Experiment 1, memory was affected by both the encoding and retrieval factor, but JOLs were impacted by the retrieval factor. Another comparison using a standard cued-recall test instead of the MOT, showed that JOLs were no longer influenced by the retrieval factor, but they still did not vary with attention. The results conclusively suggest that metamemory was not based on encoding factors, even when the retrieval factor is not influencing the predictions. Koriat’s (1993, 1994) accessibility heuristic can explain these results. Predictions were based on how much information came to mind when the prediction is made, regardless of whether that information is correct. Furthermore, metamemory predictions are based on heuristics that do not always follow memory outcomes.

Recent literature suggests that typical forms of encoding (i.e., elaboration) are obsolete as compared to rating words based on survival relevance (Nairne, Thompson, and Pandeirada, 2007). Information encoded using survival ratings have produced superior recall despite manipulations to quell its effect. The current study examined whether survival processing is protected against forgetting. Our results suggest that targets studied under survival processing are not immune from retrieval blocking and RI effects. No effects of survival processing were obtained.

No description available.

Event sourcing has caught the interest of many developers due to desirable features such as an implicit audit log and a simplified database design. This thesis presents a case study with a focus on managing the challenges of versioning and correcting incorrect states. The techniques upcasting and support multiple versions are investigated for handling versioning within event sourcing. Partial and full reversal techniques are applied to investigate the correction of incorrect states. The techniques will be implemented within an event sourcing prototype written in F# to demonstrate how the techniques behave in practice, which can be of use for developers that want to endeavor into event sourcing projects. The results of the study show that all investigated techniques can handle the associated challenges. The comparison of techniques shows the advantages and disadvantages associated with the techniques when implemented in the prototype.

Univ., Diss--Köln, 2004. / Literaturverz. S. 215 - 276.