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Steady-state visually evoked potential correlates of object recognition memoryPipingas, Andrew, apipingas@bsi.swin.edu.au January 2003 (has links)
Object recognition memory (ORM) refers to both recognition of an object and the memory of having seen it before. In humans, ORM has been investigated using functional neuroimaging and electrophysiological techniques with tests of episodic memory retrieval involving recollection of previously studied items. Processes involved in the maintenance of a mental state adopted for the performance of a retrieval task (retrieval mode) appear to involve right frontal neural regions. More transient processes occurring at the time of item recollection (retrieval success) have shown scalp activity over parietal and right frontal regions. This activity is thought to originate in the medial temporal lobes and the underlying right frontal cortex respectively. The aforementioned findings have been derived mainly from studies using verbal stimuli. It is uncertain whether the same neural regions are involved in object recollection. It is also uncertain whether sustained modal and transient item-related activity involve the same or different right frontal regions. In this study, steady-state probe topography (SSPT) was used to investigate both sustained and transient processes involved in the retrieval of abstract pictorial objects from memory. The ability to vary the evaluation period of the steady-state visually evoked potential (SSVEP) allows investigation of cognitive processes occurring over different time scales. Neural regions involved in sustained modal processes were identified by examining the SSVEP values averaged over the duration of a memory retrieval task. Sustained SSVEP effects were observed over right fronto-temporal regions. Neural regions involved in transient retrieval success processes were identified by comparing the transient SSVEP responses to tasks with different memory loads. Comparison of a higher with a lower memory load condition showed SSVEP effects over parieto-temporal and right inferior frontal regions. Larger differences between memory loads gave effects that were larger and more right lateralized. Retrieval mode and retrieval success processes showed SSVEP effects over different right frontal regions. It was also found that, in contrast to the left lateralized parietal ERP response to recollected verbal stimuli, the SSVEP effects produced with abstract pictorial shapes showed a more bilateral pattern. This was considered to reflect the relatively non-verbalizable pictorial nature of the stimuli.
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"Did I say that ?" using videotapes to aid young children�s event recallAnderson, Leigh Michelle, n/a January 2005 (has links)
The introduction of the Evidence Amendment Act (1989) in New Zealand allowed for children�s evidence to be videotaped and to be presented in court at a later time as evidence-in-chief. Typically, children see these tapes for the first time in court when they are required to be present for cross-examination, frequently months, or even years, after the evidence was recorded. From a theoretical perspective, allowing children to view a pre-recorded interview may be potentially beneficial, serving to remind the child of what was said at an earlier interview, and reactivating or �refreshing� the child�s memory of the event. It is also possible that viewing the videotape will have detrimental effects on children�s reports. For example, errors may be compounded when children see themselves make an error or complying with a suggestion on videotape.
In a series of five studies, the current thesis examined what effect, if any, viewing an earlier interview had on children�s subsequent reports about an event. In all studies presented, children took part in an event, and then were interviewed about that event 1-2 weeks later. That interview contained misinformation, which was introduced in questions. In Study 1, children watched their own videotaped interview 24 hours prior to being re-interviewed about an event in which they had participated seven months earlier. At Interview 2, the reports from these children were not very different from those of children who had no reminder, but they did report more information in free recall.
In Study 2, children viewed their pre-recorded interview immediately prior to Interview 2, rather than 24 hours prior, as in the first study. In addition, the delay between the event and Interview 2 was extended to 12 months. These changes were made to maximize any possible effects of the videotape as a reminder. In this study, there were greater differences between the reports of children who had, and who had not, viewed the earlier interview. These relative gains in information were not at the expense of accuracy.
Study 3 aimed to replicate the results of Study 2, using a larger sample. Due to circumstances beyond the Experimenter�s control, the participant number included in this study was reduced. The pattern of results in the present study was generally similar to the results observed in Study 2.
One group of participants participated in an additional event shortly before the end of the delay period between the interviews. This provided a unique opportunity to assess whether viewing a pre-recorded interview would assist with source monitoring, as the additional event was very similar to the first event. Study 4 examined this data. Results of this study indicated that the intervening visit interfered with the effectiveness of the pre-recorded interview as a memory aid. In addition, viewing the videotaped interview did not assist the children with source monitoring.
Study 5 examined whether the results from Studies 2 and 3 would generalise to a different event. The results suggested that a videotaped interview was much less effective with the different event. It is likely that this was because the event was less interactive, potentially less salient, and less familiar to the participants than the event used in the previous studies.
Study 6 combined the data from the previous five studies, in order to increase the statistical power. By doing this, it was anticipated that the consistent aspects of the results would become clearer, and that the inconsistent findings would be eliminated. Indeed, this study summarized the strengths of the earlier studies, and demonstrated that children�s reports at Interview 2 were enhanced when they viewed their videotape of Interview 1. This enhancement did not lead to an increased number of errors for the reminder group.
Taken together, these findings suggest that viewing a videotape of an earlier interview has some advantages and no detrimental effects on children�s subsequent reports. Errors spontaneously generated by the children tended to be minor, did not increase following exposure to the earlier interview, and were not repeated across the interviews. Watching a prior, videotaped interview had most benefit on increasing the information reported in free recall, and did not reduce accuracy. This is important, as free recall in interviews with children is typically accurate, but brief. Further, when asked direct questions, in some cases children who had seen a prior interview tended to be more likely to provide the correct answer. These findings are considered in the context of current legal reforms.
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Shared factors in autobiographical memory and theory of mind developmentPinder, Kirsty, n/a January 2006 (has links)
When humans use the mental states (e.g., beliefs, intentions) and the emotional states of others to predict or explain another person�s behaviour, they have demonstrated their theory of mind understanding. Theory of mind is "one of the quintessential abilities that makes us human" (Baron-Cohen, 2000, p. 3). Emotion understanding has been considered by some to be an aspect of theory of mind understanding. There are several theories proposed to explain the development of theory of mind, from changes in representational abilities (Perner, 1991), to having an innate domain specific module (Fodor, 1992; Leslie, 1994), to social linguistic influences (Nelson et al., 2003). One facet of theory of mind understanding, understanding false belief, has been consistently found to develop at around 3 or 4 years of age (e.g., Wimmer & Perner, 1983). Another cognitive ability that develops at the approximately the same time is that of autobiographical memory. Autobiographical memory has been defined as "memory for information and events pertaining to the self" (Howe & Courage, 1993, p. 306). There are also several theories explaining the onset of autobiographical memory. Two similar theories by Perner (1991) and Welch-Ross (1995) proposed that until a child possesses dual representational abilities (or theory of mind), they cannot form autobiographical memories. Nelson (1993) and Fivush (2001) have both proposed that autobiographical memory is developed through shared narratives with more experienced others (e.g., parents). There are several factors that have been found to contribute to theory of mind, emotion understanding, and autobiographical memory. Language abilities have been related to all three cognitive abilities (e.g., Slade & Ruffman, 2005; Dunn & Cutting, 1999; Harley & Reese, 1999). Factors such as maternal talk, gender of the child, and the number of siblings the child has, have all been related to at least two of these abilities. In the current study, I addressed the relation between theory of mind understanding, emotion understanding, and autobiographical memory in three studies. The first study investigated the relations between language, theory of mind, emotion understanding, and mother-child talk about past events in 61 children at three 6- month intervals from 42- to 54- months of age. The second study also investigated these factors and the children�s pretense in 59 children at 48- months of age. In the second study, the mother�s theory of mind and emotion understanding were also measured. In the third study, I investigated the relations between theory of mind, emotion understanding and early memory recall in 73 adults, with an average age of 20 years. One key finding was that, despite theoretical predictions, there was no clear relation between theory of mind understanding and autobiographical memory in either children or adults. Results showed that theory of mind and emotion understanding are related but distinct abilities. The number of siblings, or the gender of the participants were not strongly related to theory of mind, autobiographical memory, or emotion understanding. Language abilities and maternal talk were the strongest factors related to the development of theory of mind, autobiographical memory and emotion understanding.
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An item and order processing analysis of word length, generation and perceptual interference effects in human memoryHendry, Liam January 2004 (has links)
When participants are presented with lists of items for immediate serial recall, tradition would suggest that a race begins - between the need to constantly refresh or recycle the memory trace of that list, and a tendency for the memory trace to decay. Standard models in the literature assumed a complex interaction of mental subsystems whereby a controlling attentional process strove to keep the memory of such a list alive for a sufficiently long period of time so it could be remembered and output in order, using a type of recirculating loop rehearsal and storage mechanism to offset the decay process. Evidence supporting such models stemmed from the observation that more short words could be remembered in order than long words (Baddeley, Thomson, & Buchanan, 1975). This word length effect, described in the second chapter, was a crucial piece of evidence for rehearsal and decay models, in the example given, the recirculating loop was seen as being time-based and extremely limited in capacity, such that memory was deemed equivalent to the amount of information which could be cycled through the rehearsal loop in about two seconds. A number of recent challenges to this model of remembering have cast doubt on the nature of the process as described in such models as that of Baddeley (1990; 1996). Chapter 1 began by providing an overview of the development of such models from their earliest form, and also introduced some alternative ideas about the structure and function of human memory. A processing view was described, in which the probability of recalling a list of items depended not upon a race between decay and rehearsal, but on differential processing of items based on their nature. As remembering a list in its original order involves not only remembering the items themselves, but also information about how they relate together in the list, an alternate theory was advanced that in some cases the processing of information about the items, and information about their serial order could dissociate, producing a processing tradeoff. As individual items were better remembered, information about their presentation order diminished. This observation (Nairne, Riegler, & Serra, 1991) was introduced as the item-order hypothesis. The item-order hypothesis suggested that under certain conditions increased item processing could lead to deficits in order processing, and that this produced a dissociation in performance between item and order memory tasks. The generation effect (Slamecka & Graf, 1978) was one such example, as was the perceptual interference effect (Mulligan, 2000), and these were discussed in Chapter 3. The word length effect was seen as another instance where this tradeoff might be observed. A design incorporating elements of item and order tasks based upon Nairne et al. (1991) was detailed in the fourth chapter, leading on to empirical testing of the word length effect (Chapter 5), the generation effect (Chapter 6) and the perceptual interference effect (Chapter 7). This series of experiments compared word length and generation effects under serial recall and single item recognition tasks, using a range of test conditions designed to allow replication and extension of existing data from these separate streams of research. Results did not appear as predicted for some aspects of generation and all aspects of perceptual interference, and further experiments in Chapter 8 attempted to address the current findings. For the experiments involving word length, short words were better recalled than long words on the serial recall task, but long words were better recognised in the recognition task. Following additional manipulations in Chapter 8, the generation effect began to produce a similar pattern, but the results for perceptual interference were inconclusive. Word length data, however, were consistent with the item-order approach and supported a novel explanation for the word length effect. Implications and conclusions were discussed in Chapter 9.
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Informasjons- og kunnskapsrom for systemutviklingsprosjektMichalsen, Nina January 2000 (has links)
<p>Denne avhandlingen studerer hvordan gruppevare, nærmere bestemt Corporate Memories(CM), kan brukes til å støtte informasjons- og kunnskapsdeling i en systemutviklingsorganisasjon.</p><p>Studiet tar utgangspunkt i Borghoff&Pareschi’s(1998) syn på Corporate Memory som en infrastruktur for kunnskapsforvaltning i organisasjoner. CM består av fire komponenter som alle må støttes av ulike typer teknologi. Sentralt her står CSCW/gruppevare, informasjons og kunnskapsrepositorier, ontologier og bruk av metadata. Relevante sider av disse forskningsområdene er presentert i studiet. </p><p>Et informasjons- og kunnskapsrom er et spesialtilpasset perspektiv inn i organisasjonens Corporate Memory for en avgrenset del av organisasjonen. I dette studiet er det tatt utgangspunkt i systemutvikling, men prinsippene vil være de samme også for andre typer virksomhet. </p><p>Ved hjelp av infrastrukturen, CM, får organisasjonens medarbeidere tilgang til <b>informasjon, kunnskap og tjenester</b> som er tilpasset behovene i de arbeidsprosessene de utfører. Studiet presenterer et sett med krav til innhold, struktur og tjenester som må finnes i organisasjonens Corporate Memory. Hvis disse er oppfylt, vil det også være mulig å etablere de nødvendige Informasjons- og kunnskapsrommene i organisasjonen. </p><p>Informasjons og kunnskapsrommet skal aktivt bidra til at systemutviklerne gjenbruker relevant informasjon, kunnskap og erfaringer. Dette gjelder den eksplisitte informasjonen og kunnskapen som er lagret i repositorier og det gjelder den tause kunnskapen som kun er lagret i hodene på organisasjonens medarbeidere. </p><p>Avhandlingen konkluderer med at det viktigste bidraget for informasjons- og kunnskapsforvaltning i en organisasjon, er at det utvikles konseptuelle modeller for de ulike domenene i organisasjonen. Ved hjelp av metadata som avledes fra de konseptuelle modellene, kan organisasjonens informasjons- og kunnskapsressurser modelleres slik at de tilpasses virksomheten og de konkrete mål og problemstillinger som finnes her. I tillegg kan den konseptuelle modellen brukes som et redskap for bevisstgjøring, kommunikasjon, refleksjon og læring rundt arbeidsprosessene i organisasjonen. </p><p>På grunnlag av intervjuer og diskusjoner med to store prosjekter i den sentrale systemutviklingsenheten i Statoil, blir det utarbeidet en ontologi for utvalgte deler av systemutviklingprosessene i Statoil. Ontologien og metadatasettet som avledes av ontologien, kan benyttes som et rammeverk for beskrivelse og forvaltning av informasjons- og kunnskapsressurer i store systemutviklingsprosjekter. Rammeverket består av flere subsett med metadata. Et av disse subsettene er obligatorisk for alle informasjonsobjekter i systemutvikling. De andre subsettene er tilpasset spesielle typer informasjon eller støtte til spesielle problemstillinger.</p>
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Investigation of special magnetic memory devicesLee, Pedro 30 September 1966 (has links)
Three types of magnetic memory elements with emphasis
placed on low cost and batch fabrication are investigated.
The type I element consists of a wired hole in a strip of
Deltamax tape. The type II element uses a stack of magnetic
tape instead of the Deltamax. The type III element
consists of a pre-wired grid with magnetic material
deposited around the grid to simulate a wired core. The
results obtained from these investigations showed conclusively
that the type I element, referred to as apertured
Deltamax memory cell in this paper, operates
satisfactorily as a memory element. The fabrication
technology is based on etching small holes through a
thin Deltamax tape to form memory cells. The operation
of the uncompensated and compensated memory cell is
investigated. Oscillograms and graphs of the typical
characteristics response of the memory cell are presented,
and a qualitative description given.
The type II and type III elements are found
incapable of operating as a memory device because of the
magnetic properties of the available tape and magnetic
powder. Summaries of type II and III elements are given
in Appendix I and II respectively. / Graduation date: 1967 / Best scan available for figures. Original is a photocopy.
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Des effets de la catégorisation raciale et de genre dans la mémoire des visagesHuart, johanne 22 December 2005 (has links)
Ce travail s'intéresse à l'effet de la catégorisation raciale et de genre dans la mémoire des visages. Les études effectuées montrent que la première induit une polarisation de la seconde. Ainsi, des visages catégorisés dans une catégorie particulière sont rappelés comme plus typiques de leur catégorie et moins typiques de catégories alternatives. Cet effet est observé à la fois dans le cas de visages fortement ambigus catégorisés sur base du contexte et dans le cas de visages modérément ambigus catégorisés sur base de leurs traits. Les implications pratiques et théoriques de ces résultats sont discutées.
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Do actors or observers make better eyewitnesses?Colby, M. Amanda Earl. Weaver, Charles A. January 2005 (has links)
Thesis (M.A.)--Baylor University, 2005. / Includes bibliographical references (p. 57-59).
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Design and analysis of fast low power SRAMsAmrutur, Bharadwaj S. January 1900 (has links)
Thesis (Ph.D)--Stanford University, 1999. / Title from pdf t.p. (viewed April 3, 2002). "August 1999." "Adminitrivia V1/Prg/20000907"--Metadata.
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Does the shape of a view alter memory for that view?Daniels, Karen K. January 2007 (has links)
Thesis (M.A.)--University of Delaware, 2006. / Principal faculty advisor: Helene Intraub, Dept. of Psychology. Includes bibliographical references.
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