Previous investigations have suggested that visual memory may involve short-term (STVM) and long-term (LTVM) components. Evidence for this comes from the functional differences between visual memory tested after short, unfilled retention intervals (STVM conditions), and performance measured after any interpolated task with a high mental load (LTVM conditions). The suggestion is that stimulus information is maintained over short, unfilled intervals by visualization, an active, voluntary control process utilizing central resources. Under LTVM conditions interference prevents active maintenance, and the item must be memorized. The aim of this thesis was to provide further evidence on the functional distinction, and the nature of the underlying processes. A number of experiments were conducted using novel matrix patterns as stimulus materials, and on-line control to allow precise manipulation of timing and other display parameters. The dissociation of STVM and LTVM was reflected in several results: STVM and LTVM (a) have different requirements for display time (b) differ in the consistency of performance over trials (c) they involve different coding processes at acquisition and (d) they show quite different relations between accuracy of performance and mean response time. In contrast to this, varying the exposure of a recognition test probe did not dissociate STVM and LTVM performance, and the provision of feedback and retrieval cues durin recall had no clearly interpretable effect. Visualization is a limited capacity process, insofar as it is restricted to one item or presentation at a time, and can maintain information up to a certain level of complexity. Visualized descriptions are constructed rapidly from short display times, and have general application to this class of novel visual patterns. With other evidence, this suggests that visualization is based on low-level 'figural' descriptions, specifying stimuli as a spatial arrangement of shapes formed by groupings of the pattern elements. LTVM performance increases slowly and irregularly with display time and there is a wide variation in performance over trials. Higher-level, 'semantic' descriptions contribute to memorization, and these cannot be applied rapidly and consistently to randomly generated abstract patterns. The results have widespread implications for theories of visual memory. Single-process theories which deny any distinction between short- and long-term memory are ruled out by the data. Other models which (a) consider STVM as an 'activated' part of LTVM or (b) claim the dichotomy arises from simple distinctions in coding or storage or retrieval do not give a complete account of the results. The 'modal' model is also rejected since prolonged visualization of an item after stimulus offset does not lead to an increase in LTVM. To account for this latter finding, it is proposed that visualization and: the elaborate encoding processes required for memorization compete for-central processing resources.

Thesis (Ph.D.)--Texas Christian University, 2006. / Title from dissertation title page (viewed Sept. 11, 2006). Includes abstract. Includes bibliographical references.

Thesis (M.M.) Florida State University, 2007. / Advisor: Jayne Standley, Florida State University College of Music. Title and description form dissertation home page (viewed 4-6-2009). Document formatted into pages; contains 53 pages.

Thesis (M.A.)--Georgia State University, 2007. / Title from file title page. David A. Washburn, committee chair; Heather M. Kleider, Eric J. Vanman, committee members. Electronic text (65 p. : ill. (some col.)) : digital, PDF file. Description based on contents viewed May 23, 2008. Includes bibliographical references (p. 58-64).

Thesis (Ph. D.)--University of California, San Diego, 1998. / Vita. Includes bibliographical references.

No description available.

Thesis (M.S.)--Rutgers University, 2009. / "Graduate Program in Psychology." Includes bibliographical references (p. 32-34).

Thesis (Ph. D.)--Ohio State University, 1984. / Includes vita. Includes bibliographical references (leaves 87-98). Available online via OhioLINK's ETD Center.

This study set out to investigate the visuo-spatial component of Baddeley and Hitch's (1974) Working Memory framework. The development of our understanding of this component has been less dramatic than that of its verbal counterpart, the Articulatory Loop. The primary reason for this can be said to be the lack of techniques for investigation (Logie, 1986). This thesis presents one attempt to try to explore the nature of this code and to reveal possible new techniques of investigation. The following are three possible areas of investigation : 1. Is the system spatially or visually based? 2. Does movement have a role in the system? 3. How is information stored? The latter two issues are investigated here. Experiments 1-4 set out to explore the possibility that movement may be involved in the code. These experiments supported the idea that movement has a role to play in spatial coding and more specifically demonstrated that arm movements which are not compatible with the presentation of spatial material can cause disruption. In addition it was shown that when movement identical to that involved in presentation is encouraged at recall subjects show marked improvement in performance. Together these results very strongly suggest that movement should be given prominent reference in the definition of spatial coding and in the description of the visuo-spatial slave system. Another development that came out of these experiments relates to the lack of investigative techniques in the field of visuo-spatial short term memory. The fact that movement has been shown to be important suggests that techniques employed to investigate kinaesthetic memory will aid us in exploring visuo-spatial coding. The second issue in this thesis explored further the nature of the internal code. Research into the nature of coding in visuo-spatial memory had previously argued for the presence of a sequential component. Experiments 1-4 in this thesis had shown that movement had an important role to play in coding. The fact that movement by its very nature would appear to be sequential suggested that there was a strong sequential element in coding within visuo-spatial memory. However, concern was expressed that the materials and presentation format used may have led to sequential coding. This was first explored in experiments 5-8. The results supported the view that the material and presentation format used had led to sequential coding. This was further explored by Experiments 9 and 10 which illustrated that while it may be important under certain conditions, sequentiality is not always a dominant element in coding within the Visuo-Spatial Sketch Pad. This thesis has explored two of the central issues currently interesting theorists of Working Memory and has put forward suggestions for techniques which may in the future help us to advance our knowledge of the visuo-spatial component of the Working Memory framework.

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 64-71).