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Errors of recognition and reproduction of a perceived object.Clavert, Margaret Nelson. January 1949 (has links)
Changes in memory and the nature of the mnemonic trace are a source of never-ending interest, as well as of physiological importance, to the investigator. To date, no satisfactory solution has been provided as to exactly what occurs within the trace itself when increasing errors of memory are manifested with the passage of time. Traditionally there have been two opposing theories - one, supported by G. E. Müller, which maintains that forgetting consists principally of an increasing indefiniteness of the trace, and the other, originated by Wulf, who concluded, from studies pursued under Koffka’s direction, that the trace tends, not towards vagueness, but towards “better figures”. That is, in certain instances, such as in the perception of an irregular figure, the unstable organization of forces within the trace itself will tend towards equilibrium overriding the influence of external events upon it. (Wulf himself distinguished three sources of error, “normalizing”, “emphasizing” and “autonomous changes”, but Koffka later reduced these to two, namely “external influence” and “spontaneous change”). Not only this, the tendency towards stability which is manifested in increased symmetry, tendency to close a gap, sharpening, etc., will be progressive in time. [...]
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Language as a potential means of increasing the preceptual art ability of elementary school childrenBullock, Ray E. January 1978 (has links)
The purpose of this investigation was to develop instructional methods to affect the visual perceptual abilities of young children.Eleanor Gibson has described visual perception as the process by which we obtain firsthand information about the world around us. According to Gibson visual perception is a complex process of handling a multitude of visual bits of information or cues, so that a response to the information can be made. With these ideas in mind a series of language tasks were developed to encourage children to attend and respond to visual stimuli in order to investigate the extent to which language may modify or enhance visual perceptual ability.The sample for this study was comprised of ninety-four fourth grade students in four intact classes in the Eastbrook Community School Corporation, Marion, Indiana. Three groups were randomly assigned to the experimental treatments and one to the control condition. One group received in-process language training while viewing and discussing color slides of paintings; a second group received language training by exposure to semantic differential scales while viewing the same paintings; a third group received a condensed and integrated version of the treatment received by the other two experimental treatment groups;while a fourth group served as a control section and received traditional art instruction, primarily working with common art materials without specific language instruction and without viewing color slides of paintings. The subjects in all four groups were pre and post tested using the Children's Embedded Figures Test (CEFT), the MotorFree Visual Perception Test (IrwPT) and the vocabulary subtest of the Stanford Diagnostic Reading Test (SDRT).Data collected during this investigation was subjected to analysis of covariance techniques and, when significant ratios were obtained, follow-up t-tests were conducted. In addition, correlation coefficients were obtained to evaluate possible relationships between the three sets of measures. The confidence level for testing the null hypotheses was set at an alpha of .05. Review of the data led to the following conclusions:(A) Subjects receiving a condensed and integrated version of the language treatment including in-process verbalization and exposure to semantic differential scales while viewing color slides of paintings achieved significantly higher Children's Embedded Figures Test scores than subjects in the Control Group. The resulting data indicated that treatment incorporating language training tasks was more successful in affecting perceptual performance than traditional art activities.(B) Data analysis of treatment effects on subject performance as measured by the Motor-Free Visual Perception Test was found to be inconclusive. The statistical evidence indicates that although scores achieved by the three experimental groups on the WPT did increase they were not significantly improved.(C) Group performance on the vocabulary subtest of the Stanford Diagnostic Reading Test remained virtually unchanged. The abundance of verbal stimulation had no apparent effect upon language skills as measured by this instrument.This investigation made no attempt to prescribe how subjects should respond to visual stimuli, nor did it infer that these responses were either desirable or inalterable. At the same time this investigation made no attempt to assess the aesthetic effects of languagethat the inclusion of language tasks may stimulate and increase perceptual activity and ability thereby aiding children in developing perceptual skills.The most important general finding in this investigation is the facilitating effect of the combination of semantic differential scales and auditory verbal in-process response as a mode of instruction to increase visual perceptual ability. This combination of language factors evidently influenced the subjects to process pictorial information more effectively, perhaps by directing their attention to the distinctive features of the paintings.
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Object perception: separating the contributions of high and low level visual processes with event related brain potentialsPiatt, Carley Graceanna 17 December 2009 (has links)
Object recognition was studied by combining a continuous presentation paradigm and event related potentials (ERPs). Using the Random Image Structure Evolution program (RISE), the phase spectrum of object images was parametrically altered to produce a set of continuous noise-to-object sequences. The RISE technique controlled for the low level visual properties of the object image (i.e., luminance, contrast, spatial frequency). Although the stimulus transformation proceeded continuously and smoothly, perceptually, participants reported the abrupt onset of object recognition, distinct from noise, at a critical frame in the sequence. During electrophysiological recording, the critical onset frame was marked by increased activity in posterior-occipital and central-parietal components between 152 and 324 ms post stimulus onset of the critical frame. More broadly, this study also highlights the strength of the continuous presentation paradigm for investigating object adaptation effects with ERPs.
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Looking and perception in nineteenth century poetryMaxwell, Catherine January 1990 (has links)
The thesis examines a series of nineteenth century poets whose poems are concerned with complex relations of looking and perception, and concentrates on Shelley and the poets he influenced: Browning, Rossetti, Swinburne, and Hardy. It focusses on poems dealing with the visual arts and aesthetic modes of perception, and concludes with a study of Walter Pater - an unrecognised follower of Shelley - and his notions of artistic character. An emphasis on the way face and bodily form are scrutinised, in poems concerning painting, sculpture and portraiture, leads to the hypothesis that the way the poet pictures essence or character through corporeal form is correlative to the essence or character of his own poetry. The particular spatial relations and visual representations of the poetry provide an index to specific patterns of reading. At the heart of this examination is a Shelleyan conception of the "unsculptured image", the characterising force and pre-given perspective of a poet's poem, which has a primary shaping effect on his language and representations, and continues to exert itself in the poem's reading. As this "image" is an imaginative rather than purely linguistic force, the analyses of selected poems avoid reduction to considerations of language and rhetoric alone, seeking rather to engage with the question of what constitutes a writer's own essence or particularity and what gives a strong poem its compulsive power. The thesis draws on the work of the French literary critic Maurice Blanchot to inform its ideas of poetic space and depth, and to produce an understanding of the poetic text very different from that given by a classical reading; and so alter the way one perceives the poem as literary object. In addition to this, certain nineteenth century and earlier aesthetic writings, and the prose works of the poets themselves, establish the critical basis of the arguments advanced. The thesis also endeavours to follow through the arguments of traditional scholarship in order to provide critique on distinctions or departures made. Chapter I examines Shelley's 'On the Medusa of Leonardo da Vinci in the Florentine Gallery'; Chapter II deals with portraiture in Browning's 'My Last Duchess' and Rossetti's The Portrait'; Chapter III turns to the sculpture of the hermaphrodite in Swinburne's early lyric 'Hermaphroditus'; Chapter IV looks at Thomas Hardy's poems about sketches and shades; Chapter V is an epilogue in which the work of Walter Pater draws together the ideas developed in the rest of the thesis.
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Own- versus other-race face perception : social contact and the human brainWalker, Pamela M. January 2006 (has links)
The experiments in this thesis used behavioural measures and event-related potentials (ERPs) to investigate the influence of race on face processing in the brain. Previous behavioural research has highlighted an own-race effect in face processing, whereby individuals are more accurate at recognizing own-race compared to other-race faces. The current Thesis examined the own-race effect at perceptual and neural levels. Social influences on the own-race effect were also investigated, such as other-race experience, anxiety and implicit social bias, as these may account for differential own- versus other-race face processing. The main aim of the experiments contained in this thesis was to delve deeper into the examination of own and other-race face perception through a series of original experiments. Participants performed a variety of perceptual discrimination and identification tasks, and completed measures of explicit other-race experience and implicit racial bias to record their perceptions of other-race individuals. Chapters 2-4 saw the development of a new paradigm that tested the own-race effect in perception, in contrast to traditional recognition memory investigations. In Chapter 2 the own-race effect was investigated developmentally and found across three age-groups, and was larger in the two older age-groups. Chapters 3 and 4 found that the own-race effect differed across racial groups, and that social variables such as other-race experience influenced the strength of the own-race effect. In the latter experimental chapters, ERPs revealed that the behavioural own-race effect was evident at a neural level. Chapter 7 demonstrated that face-related stages of processing in the brain were sensitive to race of face. In Chapters 8 and 9, the sensitivity of face processing to own and other-race emotional expression processing was also examined. The additional social factor of emotional expression was explored in order to further the investigation of socially relevant information processing from the face. Findings from the last two experimental chapters demonstrated differential emotional face processing for own- versus other-race faces. Confirming the findings of the behavioural experiments, own- versus other-race emotion processing varied across racial groups and was subject to social influences such as other-race experience, intergroup anxiety and implicit racial bias. Overall, behavioural and neural investigations of the own-race effect demonstrated the influence of social variables such as other-race experience, intergroup anxiety and implicit racial bias on the way in which individuals processed own- versus other-race faces in the human brain.
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Sensory gain control at fixationDeVylder, Jordan 19 November 2008 (has links)
One mechanism by which spatial attention affects visual perception is through the alteration of the signal-to-noise ratio for a particular stimulus. This is known as sensory gain control. Sensory gain effects can be measured electrophysiologically through changes in the amplitude of the P1 event related potential (ERP) component. Manipulating perceptual load by increasing or decreasing task difficulty can influence spatial attention and can therefore modulate the P1 component. Sensory gain effects are well characterized with peripheral attention, but have rarely been studied at fixation. The few studies that have been conducted that look at sensory gain for foveal stimuli have yielded conflicting results, and sensory gain with centrally presented extrafoveal stimuli has only been found in emotion studies. The present study manipulated attention allocation towards foveal and extrafoveal stimuli at fixation, using two levels of perceptual load for each stimulus size. ERPs were recorded in response to stimulus onset, and tested for differences in P1 and N1 amplitude across perceptual load conditions. Sensory gain effects, as indexed by an increase in P1 amplitude with an increase in perceptual load, were predicted for extrafoveal but not foveal stimuli. Changes in P1 amplitude were not found for either type of stimuli, suggesting that sensory gain effects either may not be present at fixation or are not susceptible to manipulation by perceptual load. The N1 component was expected to increase in amplitude for high-load stimuli, due to the N1 attention effect. However, the opposite result was found, suggesting that there is an additional effect of perceptual load on early visual processing, distinct from sensory gain control.
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The effects of word potency, frequency, and graphic characteristics on word recognition in the parafoveal fieldGima, Shinye January 1982 (has links)
Thesis (Ph. D.)--University of Hawaii at Manoa, 1982. / Bibliography: leaves 96-113. / Microfiche. / vii, 113 leaves, bound 29 cm
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Lateralised deficits in visual-spatial attention in boys with attention deficit disorder /Cartwright, Stephen A. Unknown Date (has links)
Thesis (MPsych(Clin))--University of South Australia, 1995
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Concurrent processing of visual and auditory information : an assessment of parallel versus sequential processing models / Greg Evans.Evans, Greg, 1948- January 1994 (has links)
Bibliography : leaves 226-237. / xii, 237 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Psychology, 1995
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Neural theory and model of selective visual attention and 2D shape recognition in visual clutter / by Peter Lozo.Lozo, Peter January 1996 (has links)
Bibliography: leaves 328-352. / xxxi, 352 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis proposes a neural theory, Selective Attention Adaptive Resonance Theory, and a neuro-engineered solution to selective visual attention, memory guided processing and illumination invariant recognition of complete (unoccluded), but distorted 2D shapes of 3D objects in cluttered visual images. / Thesis (Ph.D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1997?
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