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1
Ross-Sheehy, Shannon. "Attentional Modulation Of Infant Visual Short Term Memory." Diss., University of Iowa, 2005. https://ir.uiowa.edu/etd/107.
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Previous work has demonstrated that infant visual short-term memory (VSTM) capacity increases dramatically between 6 and 10 months of life (Ross-Sheehy, S., Oakes, L. M., & Luck, S. J. (2003). The development of visual short-term memory capacity in infants. Child Development, 74, 1807-1822). However, it is unclear if this increase is a function of improving memory abilities, or alternatively, if it is a function of improving attentional abilities. Moreover, it is currently unknown if infants, like adults, can use attention to form stable VSTM representations in situations where they would otherwise fail. Four experiments explored the relationship between visual attention and VSTM in 5.5- and 10-month-old infants. Results indicated that 1) 10-month-old infants are able to use attention to selectively encode items into VSTM, 2) this ability does not appear to be present in younger infants, 3) this ability does not appear to interact with the complexity of the test array, and 4) attentional facilitation requires a relatively salient cue. Taken together, these results are the first to demonstrate that infant VSTM representations can be mediated by visual attention, and that this mediation relies on relatively well-developed visual attention mechanisms.
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Perez, Veronica Beth. "Identifying visual working memory capacity and symptom correlates in the schizophrenia-spectrum : relating visual working memory and attentional control /." Connect to title online (ProQuest), 2008. http://proquest.umi.com/pqdweb?did=1594960321&sid=1&Fmt=2&clientId=11238&RQT=309&VName=PQD.
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Thesis (Ph. D.)--University of Oregon, 2008.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 135-150). Also available online in ProQuest, free to University of Oregon users.
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Fukuda, Keisuke, and Keisuke Fukuda. "The Capacity of Visual Short Term Memory Determines the Bandwidth of Information Transfer into Visual Long Term Memory." Thesis, University of Oregon, 2012. http://hdl.handle.net/1794/12391.
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Visual long term memory (VLTM) research has shown that we are capable of learning a virtually infinite amount of visual information. At the same time, visual short term memory (VSTM) research has shown that there is a severe limitation in the amount of information we can simultaneously apprehend at a given time. How does the severe capacity limitation in the initial uptake of information influence the encoding of information into VLTM? To this date, there has been no direct test of such influence, and the effect of such limitation has been unclear. Here, we demonstrate that, across wide varieties of conditions, the severe-capacity limitation in VSTM dictates the encoding of information into VLTM by determining the "bandwidth" of information transfer. This finding has a substantial implication for the understanding of the role of severely-capacity limited VSTM in forming many types of VLTM representations.10000-01-01
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Derbyshire, Noreen. "Micro-affordances in visual mental imagery and visual short-term memory." Thesis, University of Plymouth, 2002. http://hdl.handle.net/10026.1/345.
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Micro-affordance effects have been reported for several different components of the reachto- grasp action during on-line visual processing (Tucker and Ellis, 1998; Ellis and Tucker, 2000; and Tucker and Ellis, 2001). One property of these effects is that they have been shown to terminate once an object is removed from view (Tucker and Ellis, 2001). This thesis describes eight experiments that examine the presence of micro-affordance effects during off-line visual processing. All eight experiments employ a stimulus-response compatibility paradigm. Three different experimental designs were employed to examine the presence of micro-affordance effects arising from the relationship between: (a) the power and precision component of the reach-to-grasp action and the compatibility of an object for grasping with either a power or precision grasp, and (b) the orientation of an object for grasping and hand of response. The results of the experimentss uggestt hat: (a) the representationsu tilised during off-line visual processing can potentiate actions arising from the two components of the reach-tograsp action investigated;( b) the representationsu tilised during off-line visual processing can also inhibit micro-affordance effects; (c) main effects of object orientation (faster response times to either left or right-oriented objects) in those experiments examining the relationship between the orientation of an object for grasping and hand of response can be used to support a theory for the existenceo f prototype object representationsh, eld in long term memory, for the process of object recognition, and (d) due to differences in the object properties thought to give rise to micro-affordance effects, and the existence of different off-line visual processes,d ifferent experimentald esignsa re required to elicit microaffordance effects arising from the two types of micro-affordance effects investigated in this thesis.
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Dent, Kevin. "Representation and capacity in visual-spatial short-term memory." Thesis, Lancaster University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418879.
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Murray, Alexandra. "The capacity and precision of visual short-term memory." Thesis, University of Oxford, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.558547.
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Despite continued interest in the capacity limitations of Visual Short-Term Memory (VSTM), there is uncertainty as to how these limited resources are distributed: among a limited number of high resolution slots or flexibly according to task demands. This thesis extends current knowledge by exploring how top-down and perceptual mechanisms affect VSTM capacity. The General Introduction describes the current understanding and investigation of capacity limits. This appraisal extends into Chapter 2, which focuses on the specific behavioural, psychometric, and electrophysiological approaches taken in this thesis to estimate effects on the precision and probability of recall of VSTM representations. Most experiments used a change-detection task that parametrically varied the precision of the VSTM representations required for accurate responses. Chapter 3 presents an event- related potential (ERP) study involving a pre-cue, which enabled a shift of spatial attention in anticipation of an upcoming memory array. ERP signatures of anticipatory spatial attention predicted behavioural cueing benefits. As a complement, the study in Chapter 4 involved orienting attention to items already in VSTM. Results from both chapters suggest that attention affects the probability of recall rather than the precision of representations. Chapter 5 describes four experiments exploring the ability to trade the number versus precision of representations in VSTM according to task goals. No flexibility was found in setting this trade-off, suggesting that the balance between number and precision is mainly determined by stimulus driven factors. Experiments in Chapter 6 investigate whether and how competitive dynamics that characterise perceptual processing continue to influence VSTM representations. Competition among item features that were orthogonal to the task relevant features continued to influence performance. Perceptual differences between the conditions cannot account for this effect. Competitive effects were consistent across spatial and non-spatial dimensions. The General Discussion synthesises all results and highlights opportunities for future research.
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Konstantinou, N. "The role of visual short term memory load in visual sensory detection." Thesis, University College London (University of London), 2011. http://discovery.ucl.ac.uk/1335839/.
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In this thesis I established the role of Visual Short-Term Memory (VSTM) load in visual detection while comparing to the roles of perceptual load and Working Memory (WM) cognitive control load. Participants performed a short-term memory task combined with a visual detection task (as well as attention task, Chapter 2) during the memory delay. The level and type of load was varied (perceptual load, VSTM load or WM cognitive control load). Measures of detection sensitivity demonstrated that increased VSTM load and perceptual load have both resulted in impaired detection sensitivity that was of equivalent magnitude. In contrast, increased WM cognitive control load had either no effect on detection or under some conditions (when the detection task was combined with an attention task of higher priority) resulted in enhanced detection sensitivity, the opposite effect to VSTM load. The contrasting effects of different types of memory load rule out alternative accounts in terms of general task difficulty. Other interpretations in terms of changes in attention deployment, response bias, task priorities, verbal strategies, were also ruled out. These VSTM load effects lasted over delays of 4 seconds, were generalized to foveal, parafoveal and peripheral stimuli, and were shown to be predicted from estimates of the effects of load on VSTM capacity. fMRI results (Chapter 4) showed that high VSTM load reduces retinotopic V1 responses to the detection stimulus and psychophysics experiments (Chapter 5) showed that high VSTM load resulted in reduced effective contrast of the detection stimulus. These results in this thesis clarify the distinct roles of WM maintenance processes from those of WM cognitive control process in visual detection. These findings provide further support to the sensory recruitment hypothesis of VSTM, clarify previous discrepancies in WM research and extend load theory to account for the effects of VSTM load on visual detection.
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Holt, Jessica Louise. "Investigating visual short-term memory capacity within and between hemifields." Thesis, University of Leeds, 2014. http://etheses.whiterose.ac.uk/7626/.
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A number of non-mnemonic tasks have revealed the existence of a bilateral field advantage (BFA; i.e. the increase in processing capacity when information is distributed across the two visual fields relative to within a single hemifield) in visual processing. Recent research suggests that the BFA may also extend to visual short-term memory (VSTM). However to date, studies have produced inconsistent findings, demonstrating a BFA in VSTM for spatial locations and orientations but not for colours (Delvenne, 2005; Umemoto, Drew, Ester, & Awh, 2010). Two possible hypotheses may account for those findings. The first suggests that the BFA is a feature of processing spatial information but not identity information (the stimulus domain hypothesis) whilst the second claims that the BFA is a feature of attentional selective processing (the attentional selection hypothesis). With the primary aim to uncover the conditions which promote a BFA in VSTM, the present thesis tested those hypotheses. Since the stimulus domain hypothesis predicts no possibility of a BFA for colour VSTM, Part One investigated whether colour VSTM may exhibit a BFA when the task demands on selective attention are increased. The findings revealed this to be the case, highlighting that the requirement to attentionally filter spatially distinct target stimuli from distracter stimuli promoted the BFA. In Part Two, selective attention was also found to promote a BFA in colour VSTM during maintenance. Specifically, the findings suggest that bilaterally encoded items can better survive decay in VSTM when spatial selective attention is oriented to stimuli locations at the encoding stage. Overall, the findings strongly suggest that the BFA in VSTM is a signature of attentional selective processing during VSTM encoding and VSTM maintenance. Those findings have important implications for our understanding of the capacity limits of VSTM and attention, and interhemispheric communication more generally.
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Ng, Chun-hung Alexander, and 吳鎮雄. "The role of working memory in visual attention." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B46600309.
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Kornisch, Myriam. "Visual and Verbal Short-Term Memory Correlates of Variability in Vocabulary Size." Thesis, University of Canterbury. Communication Disorders, 2012. http://hdl.handle.net/10092/6737.
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This study investigated the relationship between working memory and language in typically developing young children. The aim was to gain a better understanding of language development, in particular, the involvement of visual and verbal short-term memory in language acquisition and its influence on vocabulary size. It explored possible underlying causes of why some children have problems in the process of learning to talk, whereas other children acquire language easily. A total of 51 New Zealand English speaking children aged two to five completed a battery of assessments measuring receptive and expressive vocabulary and visual and verbal short-term memory. The standardized tests administered included the Receptive One Word Picture Vocabulary Test (Brownell, 2000b), the Expressive One Word Picture Vocabulary Test (Brownell, 2000a), the Visual Patterns Test (Stokes, Klee, Cruickshank, & Pleass, 2009), and the Test of Early Nonword Repetition (Stokes & Klee, 2009a). Receptive vocabulary knowledge was strongly associated with visual (r = .75) and verbal (r = .60) short-term memory performance and age (r = .72). The relationship of expressive vocabulary to visual short-term memory (r = .80) was stronger than to verbal short-term memory (r = .62) but significant for both and also for age (r= .83). Significant unique predictors for expressive vocabulary were age (R2 change = .60) as well as visual (R2 change = .04) and verbal (R2 change = .04) short-term memory. However, age appeared to be the only unique predictor for receptive vocabulary (R2 change = .54). In addition, the findings suggested that visual and verbal short-term memory increases as children get older. Hence, the Visual Patterns Test and Test of Early Nonword Repetition seem to be good predictors, over and above age, of expressive vocabulary knowledge.
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Lejeune, Marc. "Life-span changes in visuo-spatial short term memory." Thesis, University of Stirling, 1997. http://hdl.handle.net/1893/22862.
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Several experiments are presented to evaluate the development of visuo-spatial short term memory from childhood to old age (from five-year-olds to about 70-year-olds). Visuospatial short term memory was assessed through transformational imagery tasks. The first set of experiments (chapters 3, 4 and 5) concerned the development of mental rotation abilities. A review of the literature suggested that young children (specifically so-called preoperational children) and elderly people are poor at rotating a mental image of a visual pattern. However, as some mental rotation abilities have been reported while using Shepard's paradigm, attention was focussed on the role of the first steps necessarily taken while performing a mental rotation task, specifically the maintenance of a visual pattern in STM. The second set of experiments (chapter 6) considered another imagery subsystem, namely "mental scanning". Like mental rotation, it requires the maintenance of a visual pattern in short term memory. Image maintenance ability has been assessed in reference to Kosslyn's (1994) model although Baddeley's (1986) working memory model- specifically, Logie's (1995) revision of the VSSP - has been sometimes considered while interpreting the data. These two different theoretical models suggest the existence of two related but different subsystems for sorting visual and spatial information. Most of the data presented in this thesis suggest that young children and the elderly have some difficulties maintaining spatial characteristics of a visual pattern in short term memory, i.e. the orientation of the stimulus in the mental rotation tasks and the location of targets in the mental scanning tasks. These results tend to provide some developmental evidence for a dissociation between the dorsal and ventral subsystems. It seems that the two subsystems develop at different speeds. The ventral subsystem might be better developed earlier than the dorsal subsystem. Similarly, some data suggest that the same ventral system is not yet affected by ageing when the dorsal subsystem has already begun to deteriorate.
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Chen, Zhijian 1972 Cowan Nelson. "Boundary conditions for a visual working memory capacity model." Diss., Columbia, Mo. : University of Missouri--Columbia, 2009. http://hdl.handle.net/10355/7013.
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Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 26, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dissertation advisor: Dr. Nelson Cowan. Vita. Includes bibliographical references.
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Horne, Mark James. "Differential visual short term memory performance between young and healthy older adults." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/17279.
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The research reported was inspired by the Perfect and Maylor (2000) chapter ‘Rejecting the Dull Hypothesis’. This suggested that cognitive ageing research should not focus purely on whether younger adults outperform older adults on a given task. Hartley, Speer, Jonides, Reuter-Lorez and Smith (2001) showed that older adults do not maintain the dissociability of naming identity, visual identity, and spatial location abilities that is seen in younger adults. Away from the ageing literature, Brown, Forbes and McConnell (2006) demonstrated improvement in visual task performance when the availability of verbal coding was increased. The hypothesis that older adults are less likely to use task specific cognitive mechanisms during short-term visual memory tasks was explored. This was carried out by means of a series of 8 experiments (outlined below), which broadly looked at differences in verbal interference effects on visual task performance, differences in Visual Patterns Task performance based on the availability of verbal encoding, and assessed for age-related differences in interference from an executive task in Visual Patterns Task performance. Data was interpreted through the prism of the Scaffolding Theory of Aging (Park & Reuter-Lorenz, 2009), which suggests that compensatory recruitment is employed both young and older adults in response to extrinsic challenges such as task difficulty, and intrinsic challenges, such as declining performance with age. Experiments 1-3 focused on differential effects of articulatory suppression on visual task performance between young (18-25) and older (60-75) adults. Older adults showed negative effects of suppression in short-term maintenance tasks that were not present in younger adults. Both age groups showed negative effects in a mental image rotation task. This suggested a level of verbal activation in visual tasks for both age groups, but that this activation was more common in older adults. Experiments 4-5 assessed differences in Visual Patterns Task performance between both age-groups depending on the availability of verbal encoding. Younger adults displayed the benefit of available verbal encoding with simultaneous but not sequential presentation of information. Older adults showed a benefit of verbal coding in the simultaneous task if the sequential task featured ordered, not randomised presentation pathways. This suggested that older adult task performance may be affected by all conditions within an experiment, not just the current manipulation condition. Experiments 6-7 demonstrated that older adults’ performance in the simultaneous presentation version of the Visual Patterns Task is affected by the availability of verbal encoding in the first task presented to them. Mean performance on subsequent conditions was higher when ‘high verbal coding’ patterns were seen in the first instance. This was not the case for younger adults. The demonstration of a benefit to performance from the ‘high-verbal coding’ pattern set compared to the ‘low-verbal coding’ set was a marker of higher overall performance across all task conditions for younger adults, but not for the older group. This suggested that even if verbal activation during visual task performance was an occurrence for older adults, it was not necessarily a marker for improved performance. Experiment 8 demonstrated that there were no age-related differences in the level of interference from an executive task (Random Month Generation) on Visual Patterns Task performance. This suggested that older adults do not try to actively recruit executive processes during Visual Patterns Task performance to any greater extent than younger adults do. It is suggested that older adults do use specialised task mechanisms to a lesser extent than younger adults in visual memory task performance. It is likely that this is a passive outcome of a decreased inhibition of verbal coding mechanisms, rather than an active attempt to maintain performance through the recruitment of executive cognitive resources. This is seen by the lack of age-group effects from executive interference tasks.
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Davies, Simon J. "Perceptual completion and object-based representations in visual short-term memory." Thesis, Lancaster University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.429960.
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Killin, Lewis Oliver Jack. "Investigating the short term memory visual binding impairment in Alzheimer's Disease." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/25963.
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Patients with Alzheimer’s Disease (AD) demonstrate a sensitive and specific short-term memory impairment for visual bindings (e.g. the combination of shapes and colours) that is absent in healthy ageing (Parra et al., 2009) and other dementias (Della Sala et al., 2012). This impairment is also seen in cases of asymptomatic, familial AD (Parra et al., 2010). The visual short term memory binding (VSTMB) impairment in AD has clear clinical and neuropsychological implications which are investigated in this thesis. Firstly, the utility of the VSTMB paradigm was contrasted with the Free and Cued Selective Reminding Task with Immediate Recall (FCSRT-IR) – which has recently been posited as a useful diagnostic marker of AD pathology (Dubois et al., 2014). The results indicated that the former is not affected by age, where the latter is, suggesting that the VSTMB paradigm provides a suitable baseline to measure cognitive decline associated with AD. The development of a parallel version of the FCSRT-IR is also reported. Secondly, a 24-week longitudinal study of patients receiving treatment for AD (donepezil hydrochloride) revealed that patients who respond to this treatment on cognitive scales also experience change in VSTMB performance. These responders, however, did not significantly improve on the FCSRT-IR during the study. This suggests that anticholinergic treatment may have an effect on VSTMB performance. Additionally, a meta-analysis that investigates the effect of a study’s funding on donepezil RCT outcome showed that industry-funded studies report larger changes in cognition than independent studies. Lastly, an auditory binding experimental paradigm was developed, with a view to reveal a non-visual binding impairment in AD, investigating whether the binding impairment reflects a general or modality-specific memory impairment. The overall conclusions of this thesis confirm that the VSTMB impairment has significant promise as an index of AD. The auditory binding paradigm, by contrast, shares conceptual similarity with the VSTMB paradigm, but may have restricted clinical use within the AD patient population.
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Heitz, Richard P. "Individual differences in working memory capacity and visual attention." Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/28635.
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Ralston, George Eastop. "Visuo-spatial working memory." Thesis, University of St Andrews, 1988. http://hdl.handle.net/10023/9595.
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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.
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Veldsman, Michele. "Individual differences in the capacity and precision of visual short-term memory for complex objects." Thesis, University of Cambridge, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708294.
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Blacker, Kara J. "The Effects of Action Video Game Training on Visual Short-term Memory." Diss., Temple University Libraries, 2013. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/225466.
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PsychologyPh.D.
The ability to hold visual information in mind over a brief delay is critical for acquiring information and navigating a complex visual world. Despite the ubiquitous nature of visual short-term memory (VSTM) in our everyday lives, this system is fundamentally limited in capacity. Therefore, the potential to improve VSTM through training is a growing area of research. An emerging body of literature suggests that extensive experience playing action video games yields a myriad of perceptual and attentional benefits. Several lines of converging work provide evidence that action video game play influences VSTM as well. The current study utilized a training paradigm to examine whether action video games cause improvements to the quantity and/or the quality of information stored in VSTM and whether these VSTM advantages extend visual working memory (VWM). The results suggest that VSTM capacity is increased after action video game training, as compared to training on a control game, and that some limited improvement to VSTM precision occurs with action game training as well. The VSTM improvements seen in individuals trained on an action video game are not better accounted for by differences in motivation or engagement, differential expectations, or baseline differences in demographics as compared to the control group used. However, these findings do not appear to extend to measures of VWM, nor to verbal working memory. In sum, action video game training represents a potentially unique and engaging platform by which this severely capacity-limited VSTM system might be enhanced.
Temple University--Theses
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Gonzalez, Celene. "THE EFFECTS OF WORKING MEMORY CAPACITY AND TRAIT ANXIETY ON VISUAL SHORT-TERM MEMORY PERFORMANCE." CSUSB ScholarWorks, 2019. https://scholarworks.lib.csusb.edu/etd/859.
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Anxiety is of importance within the field of cognition because it is often associated with adverse effects on attention, information processing, learning and memory (Eysenck, 1992, 2007). In existing literature, it has been reported that trait anxiety hinders cognitive performance (i.e., working memory capacity WMC). However, the relationship between trait anxiety and cognitive performance might be moderated by working memory capacity (WMC). For example, Owens (2014) reported that trait anxiety was negatively correlated with cognitive performance in the low WMC group and positively correlated to cognitive performance in the high WMC group. Although, past research on the working memory system has focused on the impairments that are triggered by trait anxiety, there may be an exception to these existing findings. Recently, Moriya & Sugiura (2012, 2018) reported that high trait anxiety paradoxically enhances visual-short term memory capacity (VSTMC). In this present study, we sought to identify if WMC modulates the relationship between trait anxiety and VSTM performance. Our first hypothesis stated that there would be a positive correlation between trait anxiety and VSTM capacity. Our second hypothesis stated that the correlation between trait anxiety and VSTM capacity would be modulated by WMC. In this current study, working memory, visual-short term memory and self‐report levels of trait anxiety, were evaluated. The results of the current study did not provide strong support for neither of our hypotheses. For hypothesis 1, we were not able to replicate Moriya and Sugiura’s findings; trait anxiety did not enhance VSTM performance. For hypothesis 2, VSTM performance was not influenced by the interaction term of WMC x trait anxiety; in such WMC and trait anxiety combined were unrelated to VSTM performance. Despite this work, we are still somewhat unclear whether trait anxiety enhances VSTM performance. Although, our data did not provide definitive support for enhanced VSTMC in high trait anxious individuals it did provide three unique findings. First, our results suggest that the level of WMC does in fact modulate the relationship between trait anxiety and VSTMC. Second, only the somatic component of trait anxiety was negatively correlated to VSTM performance for LWMC individuals. Third, WMC and VSTMC were significantly associated with one another. In closing, our three core findings may provide important insights towards improving future research when assessing the relationship between trait anxiety and VSTM performance.
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Kornblith, Simon (Simon John). "Spiking and oscillatory correlates of visual short-term memory for multiple items." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/113953.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Brain and Cognitive Sciences, 2017.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 119-132).
The richness of visual experience far exceeds our ability to remember what we have seen. However, it is unclear what neural mechanisms give rise to these limits to visual short-term memory capacity. Here, we measured neural activity in a change localization task, in which monkeys viewed two displays of multiple colored squares separated by a brief delay, and made a saccade to the square that changed color between displays. In chapter 2, we examine local field potentials in the lateral intraparietal area (LIP), frontal eye field, and lateral prefrontal cortex (PFC). At stimulus encoding, lower frequency oscillations decreased in power in proportion to the total number of stimuli presented, while higher frequency oscillations increased in power in proportion to the number of stimuli contralateral to the recording site. During the delay, lower frequency power instead increased with the number of contralateral stimuli, while higher frequency power was not modulated. We interpret these findings in terms of roles for low- and high-frequency oscillations in changing and maintaining cognitive state. In chapter 3, we compare spiking activity between LIP, PFC, and inferotemporal cortex (IT). Although the task required that the animal remember stimulus colors, activity in LIP and PFC primarily reflected the stimulus positions, while activity in IT primarily reflected color. In PFC, color information increased with the number of stimuli presented, while in IT, color information remained constant or decreased. Thus, IT was more strongly capacity-limited than PFC. Color selectivity during the delay was weak in all regions. However, in IT, activity at test stimulus presentation reflected the difference in square colors between the sample and test displays, while in PFC, activity primarily reflected the location of the changed square. Selectivity to these attributes was stronger on correct trials than incorrect trials. Our findings suggest a possible role for passive processes in IT in visual short-term memory.
by Simon Kornblith.
Ph. D.
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Tan, Wah Pheow. "The role of visual short-term memory in object-based attentional selection." [Ames, Iowa : Iowa State University], 2009. 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:3355537.
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Miller, Claire Elizabeth. "The effect of inter-stimulus competition on visual short-term memory capacity." Thesis, Bangor University, 2016. https://research.bangor.ac.uk/portal/en/theses/the-effect-of-interstimulus-competition-on-visual-shortterm-memory-capacity(ed2a4604-89e5-43c1-b273-19f8e3ff2b30).html.
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A study by Ihssen, Linden and Shapiro (2010) increased visual short-term memory (VSTM) performance by either repeating an 8-item array, or presenting it across two 4-item sequential displays. These increases were suggested to occur due to decreases in overall inter-stimulus competition, enabled in a top-down and bottom-up manner respectively (Ihssen, Linden, Miller & Shapiro, 2015). These studies add to growing evidence that reducing competition in visual cortex may improve VSTM performance (see Shapiro & Miller, 2011). This thesis sought to further investigate the effects of competition on VSTM, through manipulation of both bottom-up and top-down elements of inter-stimulus competition. Bottom-up competition was manipulated by varying properties of to-be-remembered sequential stimulus displays; more specifically by presenting either a similar number of items in each display or several more items in one display than the other. Reducing overall inter-stimulus competition using this manipulation elicited increased VSTM performance. Further experiments considered the ability of participants to use top-down cues to manipulate VSTM contents. The novel cueing paradigm used in Chapter 5 revealed specific impairments in inhibiting the encoding of new stimuli at short notice, whilst holding items in VSTM. In contrast, VSTM could be easily updated when participants were required to remove old items and encode new ones in their place. The effect of ageing on the top-down and bottom-up aspects of Ihssen et al.’s findings was also investigated, to determine whether the multiple stimulus display presentation may help to compensate for VSTM decreases seen in older adults (e.g., Jost, Bryck, Vogel & Mayr, 2011). In addition, the ERP experiments reported in Chapter 3 manipulated low-level competition by varying inter-stimulus proximity. Significantly, evidence of competition was found in the initial feedforward V1 response, using a novel method developed to assess competition throughout visual cortex by measuring early visual ERP components. This method has future potential for assessing competition present in visual cortex, and the contribution of feedforward and feedback processes at different time points to perceptual and cognitive processes.
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Bleckley, M. Kathryn. "Working memory capacity as controlled attention : implications for visual selective attention." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/28885.
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Liu, Tong Tina, and 刘彤. "High and low: the resolution of representations in visual working memory." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hub.hku.hk/bib/B50900109.
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Visual working memory (VWM) has long been considered to be limited in capacity, but the way in which it is limited remains unclear. One of the theoretical debates in visual working memory concerns whether the number of objects that can be stored is fixed (discrete slot models) or variable (flexible resource models). Recent research on the resolution of VWM has helped elucidate this debate by acknowledging an important trade-off between number and resolution: as the number of items stored increases, the resolution of representation declines. Yet, a different conception suggests that the number and resolution may represent distinct aspects of visual working memory, evidenced by both behavioral and neuroimaging data. In this thesis, I examined three theoretical questions regarding the relationship between the number and the resolution of items in VWM. First, how does set size affect high- & low-resolution representations (differentially)? If an item limit can be evidenced in the high-resolution measure, but not in the low-resolution measure, my second research question emerges. That is, how much resolution do we have for the remaining objects when the item limit is exceeded? Third, if both high- & low-resolution representations of an item exist in VWM, are they stored together or independently?
In a series of five experiments, I addressed these questions using an adapted continuous report paradigm, in which participants were asked to remember a mixture of objects from two categories and respond firstly to the category of the item-to-report (low-resolution measure), followed by a second within-category response (high-resolution measure) which was contingent on the first. In Experiments 1-2, only performance in the low-resolution, but not in the high-resolution, measure was largely indifferent to set size, which was not compatible with either discrete slot or flexible resource models, but was largely consistent with predictions from the two-factor model and the neural object-file theory. In Experiments 3-4, precision of high-resolution representations declined monotonically until the set size reached around four items, fitting to the predictions from discrete slot models. The overall accuracy in low-resolution measure, however, remained relatively high, suggesting differential set size influence on high- and low-resolution representations. In Experiment 5, capacity comparison revealed no significant difference when the low-resolution task was absent. Taken together, I demonstrate that 1) both low-resolution ensemble representations and high-resolution individual item representations exist in VWM, and 2) high-resolution representations (i.e. object identity) and low-resolution representations (i.e. objects’ categories, configural information and perhaps some coarse feature information) of an object might be stored independently.published_or_final_version
Psychology
Master
Master of Philosophy
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Possin, Katherine L. "Visuospatial and visual object cognition in early Parkinson's disease." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2007. http://wwwlib.umi.com/cr/ucsd/fullcit?p3250074.
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Thesis (Ph. D.)--University of California, San Diego and San Diego State University, 2007.Title from first page of PDF file (viewed April 4, 2007). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 128-166).
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Barrett, Natasha Ann. "Estimating the Capacity of Visual Short-Term Memory: A Transcranial Doppler Sonography Study." Digital Archive @ GSU, 2007. http://digitalarchive.gsu.edu/psych_theses/44.
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Estimates of the capacity of visuospatial short-term memory (VSTM) have ranged from less than 1 item to 4 +/- 1 items. The purpose of the present study was to find the capacity of VSTM by looking at the contribution of the other working memory systems (phonological loop and central executive) and determine the factor that limits VSTM capacity (either number of objects or object complexity). In this study, the psychophysiological measure of cerebral blood flow velocity also was incorporated to determine whether changes in cerebral blood flow velocity were indicative of VSTM performance and capacity. Both performance measures and cerebral blood flow velocity indicate that capacity for random polygons is approximately one object. Complexity of the objects affected capacity, such that simple objects had higher capacities and lower cerebral blood flow velocity than complex objects. Other working memory systems were not found to have an effect on performance.
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Schwarb, Hillary. "Optimized cognitive training: investigating the limits of brain training on generalized cognitive function." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/47599.
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Since antiquity, philosophers, theologians, and scientists have been interested in human memory; however, researchers today are still working to understand the capabilities, boundaries, and architecture. While the storage capabilities of long-term memory are seemingly unlimited (Bahrick, 1984), working memory, or the ability to maintain and manipulate information held in memory, seems to have stringent capacity limits (e.g., Cowan, 2001). Individual differences, however, do exist and these differences can often predict performance on a wide variety of tasks (cf. Engle, 2001). Recently, researchers have promoted the enticing possibility that simple behavioral training can expand the limits of working memory which indeed may also lead to improvements on other cognitive processes as well (cf. Morrison&Chein, 2011). The current study investigated this possibility. Recommendations from the skill training literature (cf. Schneider, 1985) were incorporated to create optimized verbal and spatial working memory training tasks. Significant performance improvements were evident across eight days of cognitive training using verbal and spatial adaptive n-back procedures. Training-related improvements were also evident for some untrained measures of visual short-term memory, attentional control, and working memory. These training effects, however, were not universal. Other measures of visual short-term memory and attentional control, as well as measures of fluid intelligence were unaffected by training.
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Barrett, Natasha. "Estimating the capacity of visual short-term memory a transcranial doppler sonography study /." unrestricted, 2007. http://etd.gsu.edu/theses/available/etd-11272007-104111/.
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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).
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Johnson, Andrew J. "Modularity in short-term memory : a comparison between olfactory, visual and auditory stimuli." Thesis, Cardiff University, 2007. http://orca.cf.ac.uk/54673/.
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This thesis is concerned with memory modularity. Recognition and serial position recall for sequences of odours, unfamiliar-faces and pure-tones is examined and compared. In the first set of experiments, 2-alternative-forced-choice (2AFC) recognition produced qualitatively equivalent serial position functions across the three stimulus types. Recency in the absence of primacy was apparent for the backward testing procedure, in contrast, the forward testing procedure produced an absence of serial position effects. This item-based task, therefore, provides some evidence for amodal processing. A second set of experiments employed a single-probe serial position recall paradigm and produced qualitatively different functions for the three stimulus types. Unfamiliar-faces showed both primacy and recency, pure-tones showed recency only and, in contrast, odours showed neither recency nor primacy. These functions were consistent across sequence length, i.e. 4-6 items. Primacy for unfamiliar-faces was immune to articulator suppression suggesting a non-verbally based representation. A third set of Experiments employed a modified serial order reconstruction paradigm in which test-items were presented sequentially rather than simultaneously. Unfamiliar-face and pure-tone stimuli demonstrated both primacy and recency, in contrast, odours demonstrated recency only. The absence of cross-stimuli functional equivalence for both order-based tasks contrasts with that for the item-based task, suggesting that item- and order-based memorial processes impact differentially upon arguments for modularity (see Guerard and Tremblay, in press). A fourth set of experiments investigated the role of verbal coding in modified-reconstruction. The functions produced for both odour and unfamiliar-face stimuli were shown not to be characteristic of verbal memory. A final study in this set employed nonwords presented both visually and aurally. Results showed that, regardless of modality of input, the functions replicated those reported above for nonverbal visual and auditory stimuli. The findings demonstrate that the functions for modified-reconstruction are not underpinned by the processes of verbalisation. In summary, the order-based tasks are consistent with modularity, where the item-based tasks support amodal processing. The findings suggest that for order memory at least, olfactory memory is qualitatively different to that of visual and auditory memory.
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Vincente, Grabovetsky Alejandro. "Exploring shared and distinct neural underpinnings in attention and visual short-term memory (using a combined univariate and multivariate approach)." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609824.
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Zoccoli, Sandra L. "Object features and object recognition Semantic memory abilities during the normal aging process /." Ann Arbor, Mich. : ProQuest, 2007. 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:3288933.
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Thesis (Ph.D. in Psychology)--S.M.U., 2007.Title from PDF title page (viewed Nov. 19, 2009). Source: Dissertation Abstracts International, Volume: 68-11, Section: B, page: 7695. Adviser: Alan S. Brown. Includes bibliographical references.
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Nemes, Vanda A. "A psychophysical investigation of human visual perceptual memory. A study of the retention of colour, spatial frequency and motion visual information by human visual short term memory mechanisms." Thesis, University of Bradford, 2011. http://hdl.handle.net/10454/5695.
Full textAbstract:
The aim of this thesis was to investigate how visual information is organised in
perceptual short term memory, with special interest in colour, spatial frequency
and velocity. Previous studies of VSTM have indicated the existence of specific
memory mechanisms for visual attributes such as orientation, spatial frequency,
velocity, contrast and colour. The retention of information in visual short term
memory for these basic visual attributes can be disrupted by the presentation of
masking stimuli during inter-stimulus intervals (ISIs), which are outside the
range of traditional sensory masking. We exploited this memory masking effect
in order to examine the organisation of visual information in VSTM. Four groups
of experiments were conducted in which participants carried out a delayed
discrimination paradigm that employed a two-alternative forced choice (2-AFC)
procedure in conjunction with a method of constant stimuli. The fidelity of VSTM
was measured by performance markers such as discrimination thresholds and
point of subjective equalities. We have found selective memory masking effects,
which serve as further evidence in favour of the modular organisation in VSTM,
namely, that human visual perceptual memory is based upon multiple, tuned
channels in case of colour, spatial frequency and speed, similar to those found
in the earliest stages of visual processing for spatial frequency. Moreover, each
of these storage mechanisms are tuned to a relatively narrow range of stimulus
parameters that are closely linked to visual discrimination mechanisms. These
findings add further support to the view that low-level sensory processing
mechanisms form the basis for the retention of colour, spatial frequency and
velocity information in perceptual memory. We also found evidence for the
broad range of transfer of memory masking effects across spatial location,
which indicates more long range, long duration interactions between channels
that are likely to rely upon contributions from neural processes located in higher
visual areas. In conclusion, the experiments presented in this thesis provide
significant insight into the organization of visual information in perceptual short
term memory.Federation of Ophthalmic and Dispensing Opticians
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Ngiam, William Xiang Quan. "Contributions of Familiarity and Chunking to Visual Working Memory Capacity." Thesis, The University of Sydney, 2019. http://hdl.handle.net/2123/20408.
Full textAbstract:
Visual working memory (VWM) is responsible for the temporary storage of visual information required for perception and cognition. The capacity of VWM is surprisingly limited to three or four items. Despite decades of research, the nature of the capacity limit is still unclear, in part due to uncertainty about the main factors contributing to this limit. We approached this issue by exploring two instances in which memory performance is enhanced. Firstly, while controlling stimulus complexity and similarity, familiarity produced significant increases in both encoding rate and capacity. However, familiarity gained from training observers to simply recognise the stimuli did not produce any benefits for change detection. Secondly, the inclusion of statistical regularities in the displays produced significantly improved recall. However, only subjects with explicit awareness of the statistical regularities showed improvement, whereas unaware subjects showed no change in their recall performance. We extended this result by observing whether contralateral delay activity (CDA), a neural marker of the number of item-based representations held in VWM, reduces with explicit chunking. Although recall performance was significantly better, the CDA did not appear to index equivalent number of chunks, suggesting that online representations do not change with the use of explicit chunking. Instead, the behavioural benefit appears to rely on retrieval of a long-term memory representation (LTM) when recall is tested. These results indicate a major influence of LTM in guiding VWM performance. Behavioural data collected at the end of the trial, such as change detection or probed recall, appear inadequate for fully examining the nature of VWM. An embedded-process framework, in which activated LTM representations can fluidly shift into the focus of attention, is useful in interpreting these results and understanding the cognitive processes involved in memory.
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Van, Horn Nicholas M. "Perceptual Learning And Visual Short-Term Memory: The Limitations And Mechanisms Of Interacting Processes." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1408731180.
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Nemes, Vanda Agnes. "A psychophysical investigation of human visual perceptual memory : a study of the retention of colour, spatial frequency and motion visual information by human visual short term memory mechanisms." Thesis, University of Bradford, 2011. http://hdl.handle.net/10454/5695.
Full textAbstract:
The aim of this thesis was to investigate how visual information is organised in perceptual short term memory, with special interest in colour, spatial frequency and velocity. Previous studies of VSTM have indicated the existence of specific memory mechanisms for visual attributes such as orientation, spatial frequency, velocity, contrast and colour. The retention of information in visual short term memory for these basic visual attributes can be disrupted by the presentation of masking stimuli during inter-stimulus intervals (ISIs), which are outside the range of traditional sensory masking. We exploited this memory masking effect in order to examine the organisation of visual information in VSTM. Four groups of experiments were conducted in which participants carried out a delayed discrimination paradigm that employed a two-alternative forced choice (2-AFC) procedure in conjunction with a method of constant stimuli. The fidelity of VSTM was measured by performance markers such as discrimination thresholds and point of subjective equalities. We have found selective memory masking effects, which serve as further evidence in favour of the modular organisation in VSTM, namely, that human visual perceptual memory is based upon multiple, tuned channels in case of colour, spatial frequency and speed, similar to those found in the earliest stages of visual processing for spatial frequency. Moreover, each of these storage mechanisms are tuned to a relatively narrow range of stimulus parameters that are closely linked to visual discrimination mechanisms. These findings add further support to the view that low-level sensory processing mechanisms form the basis for the retention of colour, spatial frequency and velocity information in perceptual memory. We also found evidence for the broad range of transfer of memory masking effects across spatial location, which indicates more long range, long duration interactions between channels that are likely to rely upon contributions from neural processes located in higher visual areas. In conclusion, the experiments presented in this thesis provide significant insight into the organization of visual information in perceptual short term memory.
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Shimi, Andria. "Attentional contributions to children's limited visual short-term memory capacity : developmental change and its neural mechanisms." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:655c9d9e-e3aa-40c5-bc51-db81a96808e4.
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It is increasingly recognised that, in adulthood, attentional control plays an important role in optimising the ability to encode and maintain items in visual short-term memory (VSTM). Memory capacity limits increase dramatically over childhood, but the mechanisms through which children guide attention to maximise VSTM remain poorly understood. Through a number of experiments manipulating different parameters, the current thesis aimed to explore the developmental trajectories of the neurocognitive mechanisms underlying selective attention within VSTM and to examine whether variations in attentional control are accompanied by individual differences in VSTM capacity. Chapters 2 and 3 investigated the development of attentional orienting in preparation for encoding and during maintenance. Younger children emerged as less able than older children and adults to orient attention to internally held representations. Therefore, Chapter 4 tested whether younger children’s attentional orienting is differentially affected by memory load. While attentional orienting prior to encoding was more beneficial when required to remember a greater number of items, cueing benefits during maintenance were similar across load conditions. Chapter 5 investigated whether temporal parameters influence younger children’s variable ability to orient attention during maintenance. Attentional orienting operated more efficiently on transient iconic traces rather than on VSTM representations due to passive decay of the memory traces as a function of time. Chapter 6 assessed whether the characteristics of the memoranda constrain the efficiency of attentional orienting within VSTM. Attentional orienting supported differentially the maintenance of familiar and meaningless items and pinpointed the quantitative improvement of mnemonic strategies over development. Finally, Chapter 7 examined the temporal dynamics of prospective and retrospective orienting of attention in VSTM. Children deployed neural pathways underpinning attentional orienting less efficiently than adults and differentially across the two orienting conditions suggesting their neural dissociation. Overall, findings from the current thesis define how children develop the ability to deploy attentional control in service of VSTM.
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Johnson, Jeffrey S. "A dynamic neural field model of visual working memory and change detection." Diss., University of Iowa, 2008. http://ir.uiowa.edu/etd/12.
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Geyer, Thomas. "Role of facilitatory and inhibitory short-term memory mechanisms for the guidance of visual search." Diss., lmu, 2005. http://nbn-resolving.de/urn:nbn:de:bvb:19-36711.
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Cuthbert, Lisa Jane. "The effects of perceptual organisation on short-term visual memory : evidence from the unitisation effect." Thesis, Lancaster University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264119.
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Duma, Gian Marco. "The impact of selective attention on information maintenance in visual short term memory: a neurofunctional investigation." Doctoral thesis, Università degli studi di Padova, 2019. http://hdl.handle.net/11577/3422333.
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Two of the most important constructs of cognitive psychology are attention and memory. These are pillars of our cognition, allowing for the selection, encoding and storing of information in order to reach our goals. Attention and memory are nevertheless very broad concepts, both emerging from the interaction of different cognitive mechanisms. In the present work, emphasis has been placed on selective attention and visual short term memory as two main computational stages of information. Furthermore, selective attention both in the temporal and spatial domains was investigated with a special focus on how differently these domains impact the succesful maintenance of visual information in short term memory. Close attention was paid to the neural activity underlying the processes mentioned above. Therefore, high-density electroencephalogram (HD-EEG) was used to provide an optimal compromise between temporal and spatial resolution. The first two chapters of this thesis provide a brief introduction of the concept of visual short term memory (VSTM) and selective attention. Next, the relationship between these two mental processes is examined by discussing some of the most relevant empirical studies on this topic. In the central chapters, it is presented new experimental evidence from two different studies. In the first study, the focus is on the effect of temporal orienting of attention (TO) on memory, targeting the encoding (Experiment 1a) and maintenance (Experiment 1b) of information as two distinct computational steps of VSTM. In the second study, it is further explored the neural patterns underlying the VSTM network identified in the first study, deepening the functional role and the relations of the relative nodes of this circuit with regard to the maintenance of visual information. The final part of the present work is dedicated to discussing the theoretical implication of the empirical findings as well as to identifying new experimental routes to pursue with the aim of extending upon the presented results.Due dei più importanti costrutti della psicologia cognitiva sono l'attenzione e la memoria. Questi sono i pilastri della nostra cognizione, che permettono la selezione, la codifica e lo stoccaggio delle informazioni per raggiungere i nostri obiettivi. Attenzione e memoria sono tuttavia concetti molto ampi, che emergono entrambi dall'interazione di diversi meccanismi cognitivi. Nel presente lavoro, l'enfasi è stata posta sull'attenzione selettiva e sulla memoria visiva a breve termine come due principali stadi computazionali dell'informazione. Inoltre, l'attenzione selettiva sia nel dominio temporale che in quello spaziale è stata indagata con particolare attenzione a come questi domini influenzano in modo diverso l'efficacia del mantenimento dell'informazione visiva nella memoria a breve termine. Particolare attenzione è stata dedicata all'attività neurale alla base dei processi sopra menzionati. Pertanto, l'elettroencefalogramma ad alta densità (HD-EEG) è stato utilizzato per fornire un compromesso ottimale tra risoluzione temporale e spaziale. I primi due capitoli di questa tesi forniscono una breve introduzione al concetto di memoria visiva a breve termine (VSTM) e di attenzione selettiva. Successivamente, la relazione tra questi due processi mentali viene esaminata discutendo alcuni dei più rilevanti studi empirici sull'argomento. Nei capitoli centrali vengono presentate nuove evidenze sperimentali tratte da due diversi studi. Nel primo studio, l'attenzione è focalizzata sull'effetto dell'orientamento temporale dell'attenzione (TO) sulla memoria, puntando alla codifica (Esperimento 1a) e al mantenimento (Esperimento 1b) dell'informazione come due distinti passi computazionali della VSTM. Nel secondo studio vengono ulteriormente esplorati i pattern neurali sottostanti la rete VSTM individuati nel primo studio, approfondendo il ruolo funzionale e le relazioni dei relativi nodi di questo circuito per quanto riguarda il mantenimento dell'informazione visiva. La parte finale del presente lavoro è dedicata alla discussione delle implicazioni teoriche delle scoperte empiriche e all'individuazione di nuovi percorsi sperimentali da perseguire con l'obiettivo di estendersi ai risultati presentati.
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Fike, Lauren. "Cross-cultural normative indicators on the Wechsler Memory Scale (WMS) associate learning and visual reproduction subtests." Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1002484.
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A comprehensive battery of commonly used neuropsychological tests, including the WMS Associate Learning and Visual Reproduction subtests, forming the focus of this study, were administered to a southern African sample (n = 33, age range 18-40). This sample composed of black South African, IsiXhosa speakers with an educational level of Grade 11 and 12, derived through DET and former DET schooling. The gender demographics were as follows; females n = 21 and males n = 12. This sample was purposefully selected based on current cross-cultural research which suggests that individuals matching these above-mentioned demographics are significantly disadvantaged when compared to available neuropsychological norms. This is due to the fact that current norms have been created in contexts with socio-cultural influences; including culture, language and quantity and quality of education distinctly dissimilar to individuals like that composed in the sample. Hence the purpose of this study was fourfold namely; 1) Describe and consider socio-cultural factors and the influence on test performance 2) Provide descriptive and preliminary normative data on this neuropsychologically underrepresented population 3) Compare test performance between age and gender through stratification of the sample and finally to 4) Evaluate the current norms of the two WMS subtests and assess their validity for black South Africans with DET and former DET schooling with comparisons to the results found in the study. Information derived from the statistical analyses indicated that a higher performance in favour of the younger group over the older age range was consistently found for both WMS subtests. With regards to gender, some higher means were evident for the male population in the sample than was produced by the female group. Lastly, due to the fact that most scores derived from the sample were considerably lower when compared to the available norms, it is felt that socio-cultural factors prevalent to this population are a significant cause of lower test performance and thus warrant the development of appropriate normative indicators.
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Vaughan, Leslie Hartman Marilyn Dina. "Age differences in the capacity of visual short-term memory effects of stimulus type and information load /." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2007. http://dc.lib.unc.edu/u?/etd,894.
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Thesis (M.A.)--University of North Carolina at Chapel Hill, 2007.Title from electronic title page (viewed Dec. 18, 2007). "... in partial fulfillment of the requirements for the degree of Master of Arts in the Department of Psychology (Cognitive)." Discipline: Psychology; Department/School: Psychology.
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曾凱玲 and Hoi-ling Tsang. "Learning a procedural task with animation: a comparison between the high and low visual spatial learners." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B31227880.
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Nees, Michael A. "Internal representations of auditory frequency behavioral studies of format and malleability by instructions /." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31838.
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Thesis (Ph.D)--Psychology, Georgia Institute of Technology, 2010.Committee Chair: Walker, Bruce; Committee Member: Bonebright, Terri; Committee Member: Catrambone, Richard; Committee Member: Corso, Gregory; Committee Member: Rogers, Wendy. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Garcia, Ricardo Basso. "Visuospatial working memory in young adults and in children with learning difficulties." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/59/59134/tde-08062013-120353/.
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Visuospatial working memory (VSWM) comprises specialised subsystems devoted to storage of visual features and spatial locations. Recently, research has been focused on understanding feature binding in memory and how bound objects are temporarily held in working memory. In the current thesis we have addressed two broad questions: What is the nature of bound visual representations in working memory? Is there a specific deficit in binding in individuals with learning difficulties? In Study 1, young adults were required to recall locations, objects and object-location bindings under visual or spatial concurrent task conditions. A clear double dissociation pattern was observed: movement discrimination mainly disrupted location memory, whereas colour discrimination mainly disrupted object memory. Such selective interference was also observed for object-location memory, suggesting that bound object representations depend on the updating of specific feature information. In Study 2, two groups of children with specific learning disabilities dyslexia and nonverbal learning disability (NLD) were compared to typically developing children in three tasks that required forward and backward recall of locations, colours, and colour-location bindings. Only children with NLD have impairments in memory for locations and colours, especially in backward recall of locations, and there were no group differences for the colour-location binding task. The patterns seen in recall of locations and colours separately were no longer present when these features had to be recalled together, suggesting the specificity of binding processes. Finally, in Study 3, two groups of children at-risk of learning disabilities (verbal and nonverbal) were compared to typically developing children in VSWM for colours, shapes, and shape-colour bindings. It was observed that memory for shape-colour binding is impaired in both groups at risk of learning disabilities, whereas memory for either shapes or colours are spared. This provides further support that problems in memory binding may be widespread across different populations with learning difficulties and atypical development. In summary, taken together, our results are in line with an associative view of binding, i.e., bound object representation results from associative links between different types of features. VSWM seems to operate on both feature- and object-level information.A memória de trabalho visuoespacial possui subsistemas especializados na retenção temporária de características visuais e localizações espaciais. Recentemente, diversas pesquisas procuram elucidar os mecanismos de integração (ou binding) de características na memória e como objetos integrados são temporariamente armazenados. Nesta tese, abordamos duas questões amplas: Qual a natureza de representações integradas na memória de trabalho? Há um déficit específico na integração de informações em indivíduos com dificuldades de aprendizagem? No Estudo 1, adultos jovens (estudantes universitários) realizaram tarefas de recordar localizações, objetos e conjunções objeto-localização em diferentes condições experimentais de interferência, que poderia ser uma tarefa concorrente visual ou espacial. Uma clara dissociação dupla foi observada: a discriminação de movimento dificultou a recordação de localizações e a discriminação de cores interferiu na recordação dos objetos. Tal interferência seletiva também foi observada na memória para conjunção objeto-localização, indicando que representações integradas dependem da atualização de traços de memória específicos. No Estudo 2, crianças com transtornos específicos de aprendizagem dislexia e transtorno de aprendizagem não-verbal (TANV) foram comparadas a crianças com desenvolvimento típico em três tarefas que exigiam a recordação em ordem direta e inversa de sequências de localizações, cores e conjunções cores-localizações. Crianças com TANV apresentaram déficits de memória para localizações e cores, especialmente quando as localizações deveriam ser recordadas em ordem inversa, e não houve diferenças entre grupos na tarefa de cor-localização. Os padrões observados na recordação de cores e localizações em separado não foram observados quando essas informações deveriam ser recordadas de maneira integrada, sugerindo a especificidade de processos de integração de características. Por fim, no Estudo 3, dois grupos de crianças em risco de transtornos de aprendizagem (verbal e não-verbal) foram comparadas a crianças em desenvolvimento típico em tarefas que exigiam memória para cores, formas e conjunções forma-cor. Foi observado que ambos os grupos com dificuldades de aprendizagem apresentaram um déficit de memória para a conjunção forma-cor, com memória preservada para cores e formas separadamente. Isso traz evidências adicionais que problemas de memória para conjunções podem ser generalizados para diversas populações com dificuldades de aprendizagem e desenvolvimento atípico. Resumindo, nosso conjunto de resultados estão de acordo com uma perspectiva associativa da conjunção ou binding, isto é, representações integradas resultam de ligações associativas entre diferentes tipos de traços ativados. A memória de trabalho visuoespacial parece funcionar com informações de ambos os níveis características básicas e objetos integrados.
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Mohamed, Helmy Abdallah May. "The role of convexity in the corner enhancement effect, in visual short-term memory, in perception of symmetry, and in shape interference." Thesis, University of Liverpool, 2012. http://livrepository.liverpool.ac.uk/7893/.
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Contour curvature information has been shown to have an impact on the visual perception of shape. We have conducted studies on perception of convexity and concavity in relation to memory and attention. Previous studies (Badcock & Westheirner, 1985; Krose & Julesz, 1989; Nakayama & Mackeben, 1989) have proposed that visual space is influenced by corners. Recent studies by Cole, Burton and Gellatly (2001) found that reaction times were faster for a stimulus located in the region of a corner of a figure. Cole et al (2001) believe that the role of corners is greater than that of straight edges, due to corners receiving a higher distribution of attentional resources relative to straight edges. The first part of this thesis considers the role figure-ground plays in the corner enhancement effect. Results demonstrate that the corner enhancement effect is only found when the probe is presented on the surface that owns the corner. Thus the corner enhancement effect is present for both concave and convex vertices. However, the effect disappears when the probe lay on the surface that does not own the corner. The second series of experiments made use of a shape with multiple concave or convex features as part of a change detection task, in which only a single feature could change. The results provided no evidence to suggest that convexities are special in visual short-term memory. Though coding of convexities as well as concavities provided a small advantage over an isolated contour. This finding is in accordance with the well documented effect of closure on shape processing (Elder & Zucker, 1993). It has been reported that deviations from symmetry were easier to detect when carried by convexities compared to deviations carried by concavities (Hulleman & Olivers, 2007). We extended this investigation to shapes that were repeated instead of reflected, to test whether there is a specific convexity advantage for bilateral symmetry. The results supported a convexity advantage for repetitions but not for reflections. Possible explanations for this are discussed. The final series of experiments involved a shape interference task; observers responded to circles or square in the context of irrelevant circles and squares. The findings suggest that interference between the shapes is much stronger when the contours that define the shapes belong to the same surface. In summary, we conclude that convexity and concavity are important aspects of shape analysis and representation, but there is no basic difference in how convexities and concavities are attended to, both in the corner enhancement effect, and in visual-short term memory. However, convexity plays a role in some perceptual tasks for example, when analyzing complex shapes observers may adopt strategies that focus on the convexities.
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Menegaux, Aurore [Verfasser], and Kathrin [Akademischer Betreuer] Finke. "The relevance of posterior thalamo-cortical connectivity for visual short-term memory capacity : evidence from aging and preterm birth / Aurore Menegaux ; Betreuer: Kathrin Finke." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2019. http://d-nb.info/1199265489/34.
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Patrocinio, Flávia Andréa Prado. "O binding da memória visual de curto-prazo em pacientes com CCL e DA." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/17/17140/tde-12042018-112836/.
Full textAbstract:
O fenômeno de binding consiste na integração de diversas caraterísticas individuais (como formas e cores) para formação de uma representação única (exemplo: formas coloridas). Estudos demonstraram que o binding na memória visual de curto-prazo se mostrou sensível às alterações precoces da doença de Alzheimer (DA). Entretanto, ainda não foi comparado o desempenho de indivíduos com comprometimento cognitivo leve (CCL), que se constitui em uma situação de risco para demência, e DA. O Objetivo desse trabalho foi caracterizar o desempenho de 3 grupos (controles saudáveis, CCL e DA) em diferentes condições da tarefa de binding da memória visual de curto-prazo, além de compará-los visando verificar se a mesma é capaz de discriminar os indivíduos com CCL de idosos saudáveis e com DA. Avaliou-se 21 controles saudáveis, 26 CCL e 19 DA nessa tarefa e numa bateria de testes neuropsicológicos de memória, atenção, funções executivas, linguagem e praxia construtiva. A performance cognitiva dos três grupos foi comparada pela análise de covariância (ANCOVA). Todas as condições da tarefa de binding foram capazes de diferenciar significativamente o grupo controle do CCL, bem como do DA. Entretanto, apenas a evocação livre binding conseguiu discriminar também CCL de DA. Esses resultados corroboram a utilização da tarefa de binding na memória visual de curtoprazo como uma ferramenta de detecção precoce de DA.Binding consists in the integration of individual characteristics (such as color and shapes) to create a single representation (exemple: colored forms). Studies demonstrated that binding in short-term visual memory is sensitive to early changes in Alzheimer\'s disease (AD). However, it has not yet been compared the performance of individuals with mild cognitive impairment (MCI), which constitutes a risk situation for dementia, and AD. The objective of the study was to characterize the performance of three groups (healthy controls, MCI and AD) in different conditions of this short-term visual memory task, in addition to comparing them to verify if it is able to discriminate individuals with MCI from healthy elderly and AD. Were assessment 21 healthy controls, 26 MCI and 19 AD in this task and in a battery of neuropsychological tests of memory, attention, executive functions, language and constructive práxis.The cognitive performance of the three groups was compared by analysis of covariance (ANCOVA). All conditions of the binding task were able to significantly differentiate the control group from CCL as well as from AD. However, only an free recall binding was able to discriminate also CCL from DA. These results corroborate the use of the shortterm visual memory binding task as an early detection tool for AD.
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Laloyaux, Cédric. "Sensitivity to changes with and without awareness: an empirical investigation." Doctoral thesis, Universite Libre de Bruxelles, 2007. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210691.
Full textAbstract:
Ce travail a pour objectif d'investiguer le sort réservé à des changements de nature visuelle qui se produisent dans notre environnement et que nous ne détectons pas consciemment. J'investiguerai en particulier si de tels changements non-perçus consciemment peuvent néanmoins (1) être représentés d'une certaine manière en-dessous du seuil de la conscience, et (2) exercer une influence causale sur des tâches comportementales subséquentes. A cette fin, une première étude cherche à établir si les paradigmes classiques de détection de changement sous-évaluent les capacités réelles de la mémoire visuelle à court terme. Cette étude a effectivement montré qu'il était possible de récupérer de l'information stockée en mémoire visuelle à court terme (MVCT), suggérant donc qu'il existe plus de capacités mnésiques visuelles que ce qui est utilisé dans les tâches classiques de détection de changement. Ensuite, une seconde étude a répliqué un paradigme dit d'identification implicite de changements et qui était controversé dans la littérature en raison de biais potentiels. Après correction de ces biais, nous avons pu démontrer que ce paradigme suggère bel et bien un effet d'identification implicite de changement puisque l'identité d'un changement simple (changement d'orientation d'un rectangle parmi 8 rectangles orientés de différentes manières) peut indicer un jugement d'orientation subséquent. Finalement, dans le dernier groupe d'expériences, un nouveau paradigme dans lequel les changements se produisent très progressivement et très lentement sera décrit. En utilisant ce paradigme, j'ai pu démontrer qu'alors que les observateurs demeurent inconscients du changement, ils restent néanmoins sensibles aux changements puisqu'ils « synchronisent » leur représentation en mémoire visuelle avec le stimulus présenté à l'écran. Enfin, dans la conclusion, je m'attacherai également à développer l'idée selon laquelle nous sommes (1) capables, au minimum, de mettre à jour notre mémoire visuelle d'un changement et probablement d'identifier, un tel changement sans conscience et (2) influençables par ce changement. En effet, à la fin de ce travail, j'arriverai à la conclusion que les représentations visuelles sont ébruitéess et incomplètes. Ceci est dû (1) à la constitution de la rétine, qui n'est pas homogène (la quantité de photorécepteurs n'est pas identique dans la partie centrale et dans la périphérie du champ visuel), (2) aux imperfections des systèmes biologiques (des imperfections et des erreurs dans la planification des saccades et dans leurs exécutions surgissent,) et (3) aux limitations de nos capacités attentionnelles.Doctorat en sciences psychologiques
info:eu-repo/semantics/nonPublished