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dc.contributor.advisorMcKeefry, Declan J.
dc.contributor.advisorBloj, Marina
dc.contributor.authorNemes, Vanda A.*
dc.date.accessioned2013-11-21T15:45:52Z
dc.date.available2013-11-21T15:45:52Z
dc.date.issued2013-11-21
dc.identifier.urihttp://hdl.handle.net/10454/5695
dc.description.abstractThe 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.en_US
dc.description.sponsorshipFederation of Ophthalmic and Dispensing Opticiansen_US
dc.language.isoenen_US
dc.rights<a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>.eng
dc.subjectVisual short term memoryen_US
dc.subject; Colouren_US
dc.subject; Spatial frequencyen_US
dc.subject; Motionen_US
dc.subject; Perceptual memoryen_US
dc.subject; Visual informationen_US
dc.titleA 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.en_US
dc.type.qualificationleveldoctoralen_US
dc.publisher.institutionUniversity of Bradfordeng
dc.publisher.departmentSchool of Optometry and Vision Scienceen_US
dc.typeThesiseng
dc.type.qualificationnamePhDen_US
dc.date.awarded2011
refterms.dateFOA2018-07-19T10:34:05Z


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