Syfte: Studiens syfte var att undersöka om BKC-tavlans ackommodativa stimulus ändras av att tillsätta optotyper av olika form, storlek och placering till den klassiska BKCtavlan. Metod: Fem olika tavlor tillverkades och jämfördes dels subjektivt med ett högneutralt BKC-test och dels objektivt med en vågfrontssensor av märket Complete Ophtalmic Analysis System (COAS HD VR™). En av tavlorna var den traditionella BKC-tavlan, de andra hade optotyper med varierande storlek, form och placering. Mätningarna utfördes på 40 cm. Mätningarna gjordes på 30 personer mellan 18 och 40 år. Resultat: De fem tavlorna visade ingen statistiskt signifikant skillnad i ackommodativ respons, vare sig med BKC eller COAS™. En tavla med små och runda centralt placerade optotyper visade en ackommodativ respons närmst det ackommodativa stimulit, mätt med COAS™ (2,31 D). Samma tavla visade en ackommodativ respons längst ifrån stimulit med BKC (2,17 D). Ingen korrelaton fanns mellan resultaten av samma tavla med de två mätmetoderna. Slutsats: Det klassiska BKC-korset ger ett lika bra ackommodativt stimulus som tavlor med tillsatta optotyper. Resultatet av en BKC-mätning med en tavla med optotyper blir inte närmre det ackommodativa stimulit, än vad ett test med den vanliga BKC-tavlan blir. Metoderna BKC och COAS™ kan inte användas ombytligen eftersom de inte var korrelerade med varandra.

Den här uppsatsen handlar om korttidsminnet (arbetsminnet) och dess kapacitet att lagra och processa information. Ett perceptionsexperiment som utfördes ger en inblick i hur korttidsminnet fungerar i praktiken och innefattar randmönster och ovaler som stimuli. Responstid och precision mäts och jämförs med avseende på betingelser som position och orientering. Uppsatsens hypotes är att samma respektive olika position på stimuli har betydelse för både snabbhet och precision. Resultatet bekräftade denna hypotes. Det visade sig också att även orientering på våra stimuli har en signifikant effekt på precision. Dock finns det ingen signifikant skillnad i snabbhet eller precision med avseende på om det är ovaler eller spatial frekvens.

Social skill deficits remain a defining feature of autism. One method to explain social behavior in autism is to explore specific antecedent-response relations. People with autism do not attend to social cues as readily as their typically developing peers thereby missing important cues that guide behavior during social interactions. The current study explored how children with autism learn antecedent-response relations using social and nonsocial stimuli as cues for reinforcement. A computerized task comprised pictures of social and non-social stimuli were presented on a computer screen. Participants were asked to respond to each picture by pressing a button if they thought pressing the button in the presence of the picture would earn them a reinforcer or to withhold pressing if they thought the picture would not earn them a reinforcer. Neither typically-developing children nor children diagnosed with ASD were able to reliably discriminate pictures. Developmental implications of these findings are discussed. / October 2015

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Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / Visual movement is important to most animals that move quickly, and even some that do not. What neural computations do animals use to see visual motion in their natural environment? The visual stimulus used to perform experiments on such questions is critical, and has historically limited the ability to perform experiments asking critical questions about responses to naturalistic moving scenes. The ability to display, at high frame rates, moving natural panoramas and other stimuli distorted to compensate for projection onto a flat screen was important to the experiments described here. I therefore created a software library called the 'Vision Egg' that allows creation of motion stimuli with recent, inexpensive computer hardware, and was used for the experiments described here. Additionally, I developed a mathematical model to determine the quality of motion simulation possible with computer displays. This model was applied to reach an understanding of the 'ghosting' artifact sometimes perceived on such apparent motion displays. Psychophysical experiments on human observers confirmed model predictions and allowed testing of synthetic motion blur for simulation of smooth motion and elimination of the ghosting artifact. I show this synthetic motion blur is optimal in the sense of creating the closest perception possible to that of smooth motion experienced in natural settings. Experiments on humans and flies show that such synthetic 'motion blur' has no effect on motion detection per se. However, ghosting in sampled displays results in information not present in smooth motion at high velocities, permitting inappropriate discrimination of rapidly moving features. I performed experiments measuring the responses of hoverfly wide-field motion detecting neurons (HS cells) in adapted and unadapted states to the velocity of natural scenes. Responses to natural images of varied intrinsic contrast depend little on the choice of image. Artificially reducing contrast, however, does reduce response magnitudes. Finally, the greatest component of response variation to natural scenes is directly related to local structure in the scenes, and could thus be called 'pattern noise.' The large receptive field of HS cells arises from a (non-linear) spatial summation of numerous elementary motion detectors. I measured spatial and temporal contrast sensitivity of small patches in the large receptive field. As predicted from the presence of a frontal optical acute zone, spatial tuning is highest frontally. A sexually dimorphic 'bright zone' in the frontodorsal eye is correlated with enhanced contrast sensitivity and faster temporal tuning in HS cells with receptive fields in this region of male flies. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1125182 / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2004

Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / Visual movement is important to most animals that move quickly, and even some that do not. What neural computations do animals use to see visual motion in their natural environment? The visual stimulus used to perform experiments on such questions is critical, and has historically limited the ability to perform experiments asking critical questions about responses to naturalistic moving scenes. The ability to display, at high frame rates, moving natural panoramas and other stimuli distorted to compensate for projection onto a flat screen was important to the experiments described here. I therefore created a software library called the 'Vision Egg' that allows creation of motion stimuli with recent, inexpensive computer hardware, and was used for the experiments described here. Additionally, I developed a mathematical model to determine the quality of motion simulation possible with computer displays. This model was applied to reach an understanding of the 'ghosting' artifact sometimes perceived on such apparent motion displays. Psychophysical experiments on human observers confirmed model predictions and allowed testing of synthetic motion blur for simulation of smooth motion and elimination of the ghosting artifact. I show this synthetic motion blur is optimal in the sense of creating the closest perception possible to that of smooth motion experienced in natural settings. Experiments on humans and flies show that such synthetic 'motion blur' has no effect on motion detection per se. However, ghosting in sampled displays results in information not present in smooth motion at high velocities, permitting inappropriate discrimination of rapidly moving features. I performed experiments measuring the responses of hoverfly wide-field motion detecting neurons (HS cells) in adapted and unadapted states to the velocity of natural scenes. Responses to natural images of varied intrinsic contrast depend little on the choice of image. Artificially reducing contrast, however, does reduce response magnitudes. Finally, the greatest component of response variation to natural scenes is directly related to local structure in the scenes, and could thus be called 'pattern noise.' The large receptive field of HS cells arises from a (non-linear) spatial summation of numerous elementary motion detectors. I measured spatial and temporal contrast sensitivity of small patches in the large receptive field. As predicted from the presence of a frontal optical acute zone, spatial tuning is highest frontally. A sexually dimorphic 'bright zone' in the frontodorsal eye is correlated with enhanced contrast sensitivity and faster temporal tuning in HS cells with receptive fields in this region of male flies. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1125182 / Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, 2004

Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains v, [37] p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 22-24).

Thesis (M.S.)--West Virginia University, 2010. / Title from document title page. Document formatted into pages; contains vi, 24 p. : ill. Includes abstract. Includes bibliographical references (p. 23-24).

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains vii, 68 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 63-65).

A series of well-defined stimuli responsive water soluble [60]fullerene (C₆₀) containing polymers such as polyelectrolytes (polyacids and polybases), polyampholyte and polyzwitterionic polymers were synthesized using atom transfer radical polymerization. The aqueous solution properties of these polymers with respective external stimuli such as pH, temperature and salt were studied using potentiometric and conductivity titration, light transmittance, laser light scattering and transmission electron microscopic techniques. The influence of polymer concentration, temperature, pH and electrolyte on the hydrodynamic radius (Rh), radius of gyration (Rg) and aggregation number (Nagg) of the particles were investigated in detail to elucidate the morphology of the particles. The morphology of the aggregates was further confirmed by the TEM micrographs. The cytotoxicity of the pH responsive C₆₀ containing well-defined polymers (PAA-b-C₆₀, C₆₀-b-PAA-b-C₆₀ and PEO-b-PAA-b-C₆₀) was studied to confirm the suitability of these particles as potential drug delivery vehicles. The binding interaction between the anti-cancer drug (doxorubicin) and C₆₀ containing pH responsive polymers was studied using isothermal titration calorimetry, and the implication of the results will be discussed. / Singapore-MIT Alliance (SMA)