The Experts below are selected from a list of 14253 Experts worldwide ranked by ideXlab platform
Soussan Djamasbi - One of the best experts on this subject based on the ideXlab platform.
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do ads matter an exploration of web search behavior Visual Hierarchy and search engine results pages
Hawaii International Conference on System Sciences, 2013Co-Authors: A H Phillips, Ruijiao Yang, Soussan DjamasbiAbstract:Users tend to ignore advertisements when viewing a web page, however, when searching for a specific product or service, advertisements can be very useful. This exploratory study examines the impact of online advertisements within search results. The findings provide support for the competition for attention theory in that users are looking at advertisements and entries when evaluation SERPs. We also examine web page search behavior and how it can affect user experience. The results show that eye tracking data is valuable for designers, marketers, and usability experts to develop and evaluate web page design.
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HICSS - Do ads matter? An exploration of web search behavior, Visual Hierarchy, and search engine results pages
2013 46th Hawaii International Conference on System Sciences, 2013Co-Authors: A H Phillips, Ruijiao Yang, Soussan DjamasbiAbstract:Users tend to ignore advertisements when viewing a web page, however, when searching for a specific product or service, advertisements can be very useful. This exploratory study examines the impact of online advertisements within search results. The findings provide support for the competition for attention theory in that users are looking at advertisements and entries when evaluation SERPs. We also examine web page search behavior and how it can affect user experience. The results show that eye tracking data is valuable for designers, marketers, and usability experts to develop and evaluate web page design.
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HICSS - Designing Noticeable Bricklets by Tracking Users' Eye Movements
2012 45th Hawaii International Conference on System Sciences, 2012Co-Authors: Soussan Djamasbi, Marisa Siegel, Thomas S TullisAbstract:To be successful, websites must not only contain useful information, but provide that information in a quickly and easily accessible manner. One method of delivering this experience is to design websites that effectively guide users' attention to key information on the page. Grounded in the model of Visual Hierarchy, this study examines several attributes that can affect users' attention to key information. Using an eye tracking device, users' eye movements were recorded while completing tasks on web pages. The results provide partial support for the model of Visual Hierarchy and indicate that tracking users' eye movement is an effective method for informing design.
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Visual Hierarchy and viewing behavior an eye tracking study
International Conference on Human-Computer Interaction, 2011Co-Authors: Soussan Djamasbi, Marisa Siegel, Thomas S TullisAbstract:Empirical evidence suggests that users often exhibit a viewing pattern that favors the top and left sides of web pages. This viewing pattern may cause users to miss a great deal of information. Grounded in the model of Visual Hierarchy, this study examines the impact of Visual complexity on how users view a page. The results show that users' viewing pattern in our study was more scattered than those reported in previous studies, which used pages with a relatively less complex Visual Hierarchy. We also examined the impact of browsing and information retrieval on viewing pattern. Such an investigation can provide insight for the design of homepages that can effectively serve both those who browse and those who retrieve information. The results also show that eye tracker can serve as a valuable tool for designers to develop and test new designs.
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HCI (1) - Visual Hierarchy and viewing behavior: an eye tracking study
Human-Computer Interaction. Design and Development Approaches, 2011Co-Authors: Soussan Djamasbi, Marisa Siegel, Thomas S TullisAbstract:Empirical evidence suggests that users often exhibit a viewing pattern that favors the top and left sides of web pages. This viewing pattern may cause users to miss a great deal of information. Grounded in the model of Visual Hierarchy, this study examines the impact of Visual complexity on how users view a page. The results show that users' viewing pattern in our study was more scattered than those reported in previous studies, which used pages with a relatively less complex Visual Hierarchy. We also examined the impact of browsing and information retrieval on viewing pattern. Such an investigation can provide insight for the design of homepages that can effectively serve both those who browse and those who retrieve information. The results also show that eye tracker can serve as a valuable tool for designers to develop and test new designs.
Stephen L. Macknik - One of the best experts on this subject based on the ideXlab platform.
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Chapter 11 Visual masking approaches to Visual awareness
Progress in Brain Research, 2006Co-Authors: Stephen L. MacknikAbstract:In Visual masking, visible targets are rendered invisible by modifying the context in which they are presented, but not by modifying the targets themselves. Here I summarize a decade of experimentation using Visual masking illusions in which my colleagues and I have begun to establish the minimal set of conditions necessary to maintain the awareness of the visibility of simple unattended stimuli. We have established that spatiotemporal edges must be present for targets to be visible. These spatiotemporal edges must be encoded by transient bursts of spikes in the early Visual system. If these bursts are inhibited, visibility fails. Target-correlated activity must rise within the Visual Hierarchy at least to the level of V3, and be processed within the occipital lobe, to achieve visibility. The specific circuits that maintain visibility are not yet known, but we have deduced that lateral inhibition plays a critical role in sculpting our perception of visibility, both by causing interactions between stimuli positioned across space, and also by shaping the responses to stimuli across time. Further, the studies have served to narrow the number of possible theories to explain visibility and Visual masking. Finally, we have discovered that lateral inhibition builds iteratively in strength throughout the Visual Hierarchy, for both monoptic and dichoptic stimuli. Since binocular information is not integrated until inputs from the two eyes reach the primary Visual cortex, it follows that the early Visual areas contain differential levels of monoptic and dichoptic lateral inhibitions. We exploited this fact to discover that excitatory integration of binocular inputs occurs at an earlier level than interocular suppression. These findings are potentially fundamental to our understanding of all forms of binocular vision and to determining the role of binocular rivalry in Visual awareness.
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Visibility, Visual awareness, and Visual masking of simple unattended targets are confined to areas in the occipital cortex beyond human V1/V2
Proceedings of the National Academy of Sciences, 2005Co-Authors: Peter U. Tse, Susana Martinez-conde, Alexander Schlegel, Stephen L. MacknikAbstract:In Visual masking, visible targets are rendered invisible by modifying the context in which they are presented, but not by modifying the targets themselves. Here, we localize the neuronal correlates of Visual awareness in the human brain by using Visual masking illusions. We compare monoptic Visual masking activation, which we find within all retinotopic Visual areas, with dichoptic masking activation, which we find only in those retinotopic areas downstream of V2. Because monoptic and dichoptic masking are equivalent in magnitude perceptually, the present results establish a lower bound for maintenance of Visual awareness of simple unattended targets. Moreover, we find that awareness-correlated circuits for simple targets are restricted to the occipital lobe. This finding provides evidence of an upper boundary in the Visual Hierarchy for Visual awareness of simple unattended targets, thus constraining the location of circuits that maintain the visibility of simple targets to occipital areas beyond V1/V2.
Serge O. Dumoulin - One of the best experts on this subject based on the ideXlab platform.
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Intracranial Recordings Reveal Unique Shape and Timing of Responses in Human Visual Cortex during Illusory Visual Events
Current biology : CB, 2020Co-Authors: Maartje C. De Jong, Serge O. Dumoulin, Frans Ss Leijten, Mariska J. Vansteensel, Raymond Van Ee, Nick F. Ramsey, H. Chris Dijkerman, Tomas KnapenAbstract:During binocular rivalry, perception spontaneously changes without any alteration to the Visual stimulus. What neural events bring about this illusion that a constant stimulus is changing? We recorded from intracranial electrodes placed on the occipital and posterior temporal cortex of two patients with epilepsy while they experienced illusory changes of a face-house binocular-rivalry stimulus or observed a control stimulus that physically changed. We performed within-patient comparisons of broadband high-frequency responses, focusing on single epochs recorded along the ventral processing stream. We found transient face- and house-selective responses localized to the same electrodes for illusory and physical changes, but the temporal characteristics of these responses markedly differed. In comparison with physical changes, responses to illusory changes were longer lasting, in particular exhibiting a characteristic slow rise. Furthermore, the temporal order of responses across the Visual Hierarchy was reversed for illusory as compared to physical changes: for illusory changes, higher order fusiform and parahippocampal regions responded before lower order occipital regions. Our tentative interpretation of these findings is that two stages underlie the initiation of illusory changes: a destabilization stage in which activity associated with the impending change gradually accumulates across the Visual Hierarchy, ultimately graduating in a top-down cascade of activity that may stabilize the new perceptual interpretation of the stimulus.
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Predicting bias in perceived position using attention field models
Journal of vision, 2016Co-Authors: Barrie P. Klein, Chris L. E. Paffen, Susan F. Te Pas, Serge O. DumoulinAbstract:Attention is the mechanism through which we select relevant information from our Visual environment. We have recently demonstrated that attention attracts receptive fields across the Visual Hierarchy (Klein, Harvey, & Dumoulin, 2014). We captured this receptive field attraction using an attention field model. Here, we apply this model to human perception: We predict that receptive field attraction results in a bias in perceived position, which depends on the size of the underlying receptive fields. We instructed participants to compare the relative position of Gabor stimuli, while we manipulated the focus of attention using exogenous cueing. We varied the eccentric position and spatial frequency of the Gabor stimuli to vary underlying receptive field size. The positional biases as a function of eccentricity matched the predictions by an attention field model, whereas the bias as a function of spatial frequency did not. As spatial frequency and eccentricity are encoded differently across the Visual Hierarchy, we speculate that they might interact differently with the attention field that is spatially defined.
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Visual motion transforms Visual space representations similarly throughout the human Visual Hierarchy.
NeuroImage, 2015Co-Authors: Ben M. Harvey, Serge O. DumoulinAbstract:Several studies demonstrate that Visual stimulus motion affects neural receptive fields and fMRI response amplitudes. Here we unite results of these two approaches and extend them by examining the effects of Visual motion on neural position preferences throughout the Hierarchy of human Visual field maps. We measured population receptive field (pRF) properties using high-field fMRI (7T), characterizing position preferences simultaneously over large regions of the Visual cortex. We measured pRFs properties using sine wave gratings in stationary apertures, moving at various speeds in either the direction of pRF measurement or the orthogonal direction. We find direction- and speed-dependent changes in pRF preferred position and size in all Visual field maps examined, including V1, V3A, and the MT+ map TO1. These effects on pRF properties increase up the Hierarchy of Visual field maps. However, both within and between Visual field maps the extent of pRF changes was approximately proportional to pRF size. This suggests that Visual motion transforms the representation of Visual space similarly throughout the Visual Hierarchy. Visual motion can also produce an illusory displacement of perceived stimulus position. We demonstrate perceptual displacements using the same stimulus configuration. In contrast to effects on pRF properties, perceptual displacements show only weak effects of motion speed, with far larger speed-independent effects. We describe a model where low-level mechanisms could underlie the observed effects on neural position preferences. We conclude that Visual motion induces similar transformations of visuo-spatial representations throughout the Visual Hierarchy, which may arise through low-level mechanisms.
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Attraction of Position Preference by Spatial Attention throughout Human Visual Cortex
Neuron, 2014Co-Authors: Barrie P. Klein, Ben M. Harvey, Serge O. DumoulinAbstract:Voluntary spatial attention concentrates neural resources at the attended location. Here, we examined the effects of spatial attention on spatial position selectivity in humans. We measured population receptive fields (pRFs) using high-field functional MRI (fMRI) (7T) while subjects performed an attention-demanding task at different locations. We show that spatial attention attracts pRF preferred positions across the entire Visual field, not just at the attended location. This global change in pRF preferred positions systematically increases up the Visual Hierarchy. We model these pRF preferred position changes as an interaction between two components: an attention field and a pRF without the influence of attention. This computational model suggests that increasing effects of attention up the Hierarchy result primarily from differences in pRF size and that the attention field is similar across the Visual Hierarchy. A similar attention field suggests that spatial attention transforms different neural response selectivities throughout the Visual Hierarchy in a similar manner.
Thomas S Tullis - One of the best experts on this subject based on the ideXlab platform.
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HICSS - Designing Noticeable Bricklets by Tracking Users' Eye Movements
2012 45th Hawaii International Conference on System Sciences, 2012Co-Authors: Soussan Djamasbi, Marisa Siegel, Thomas S TullisAbstract:To be successful, websites must not only contain useful information, but provide that information in a quickly and easily accessible manner. One method of delivering this experience is to design websites that effectively guide users' attention to key information on the page. Grounded in the model of Visual Hierarchy, this study examines several attributes that can affect users' attention to key information. Using an eye tracking device, users' eye movements were recorded while completing tasks on web pages. The results provide partial support for the model of Visual Hierarchy and indicate that tracking users' eye movement is an effective method for informing design.
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Visual Hierarchy and viewing behavior an eye tracking study
International Conference on Human-Computer Interaction, 2011Co-Authors: Soussan Djamasbi, Marisa Siegel, Thomas S TullisAbstract:Empirical evidence suggests that users often exhibit a viewing pattern that favors the top and left sides of web pages. This viewing pattern may cause users to miss a great deal of information. Grounded in the model of Visual Hierarchy, this study examines the impact of Visual complexity on how users view a page. The results show that users' viewing pattern in our study was more scattered than those reported in previous studies, which used pages with a relatively less complex Visual Hierarchy. We also examined the impact of browsing and information retrieval on viewing pattern. Such an investigation can provide insight for the design of homepages that can effectively serve both those who browse and those who retrieve information. The results also show that eye tracker can serve as a valuable tool for designers to develop and test new designs.
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HCI (1) - Visual Hierarchy and viewing behavior: an eye tracking study
Human-Computer Interaction. Design and Development Approaches, 2011Co-Authors: Soussan Djamasbi, Marisa Siegel, Thomas S TullisAbstract:Empirical evidence suggests that users often exhibit a viewing pattern that favors the top and left sides of web pages. This viewing pattern may cause users to miss a great deal of information. Grounded in the model of Visual Hierarchy, this study examines the impact of Visual complexity on how users view a page. The results show that users' viewing pattern in our study was more scattered than those reported in previous studies, which used pages with a relatively less complex Visual Hierarchy. We also examined the impact of browsing and information retrieval on viewing pattern. Such an investigation can provide insight for the design of homepages that can effectively serve both those who browse and those who retrieve information. The results also show that eye tracker can serve as a valuable tool for designers to develop and test new designs.
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Tracking Users’ Viewing Pattern
2009Co-Authors: Soussan Djamasbi, Marisa Siegel, Thomas S Tullis, Rui DaiAbstract:Empirical evidence suggests that users often exhibit a viewing pattern that favors the top and left sides of web pages (Nielsen, 2006). According to the model of Visual Hierarchy, viewing pattern is guided by two distinct cognitive processes: searching and scanning, both influenced by the attributes of the web components (Faraday, 2000). When used effectively, these attributes create a Visual Hierarchy that can guide users in viewing a page. In addition, a number of studies show that web users often exhibit a viewing pattern that is shaped like the letter “F” (Nielsen, 2006; Shrestha and Lenz, 2007). F-pattern is common to text-based pages, but can be diminished for an image-heavy page and can also be taskdependent (Shrestha and Lenz, 2007). Because images often serve as entry points to web pages (Faraday, 2000), these findings suggest that Visual Hierarchy manipulated by images may have an impact on users’ pattern of viewing. This study investigates two factors that may affect the F shaped viewing pattern: 1) Visual Hierarchy, and 2) task. Two prototypes of a homepage from a financialsrf company were designed to be different in only one section, which was named “Expert Insights”. The location of the section was below the fold of the page, a spot typically missed when users exhibit an F-shaped viewing pattern. One prototype was named Faces as its Expert Insights section included images of faces, while the other, the No Faces prototype, contained no images of faces. Because images tend to attract users’ attention, their inclusion affects the Visual Hierarchy of the homepage (Faraday, 2000). Two tasks were designed in this study: browsing and searching. In the searching task, participants were asked questions such as “You want to know more about a fall in Brazil's stocks” and needed to retrieve information which lay in the Expert Insights section. 34 participants were randomly assigned to one of the four conditions in this two-task (browse or search) X twoprototype (Faces or No Faces prototype) design. Their viewing patterns and eye fixations were collected by the non-intrusive Tobii 1750 and analyzed using heat maps. Results of this study showed that 1) consistent with previous findings, the content above the fold received more fixations overall; 2) more fixations in the center of the page were shown in the browsing task, whereas long fixations on navigations and more scattered pattern were shown in the searching task; 3) Faces prototype received more fixations on the text in Expert Insights, but No Faces prototype showed fixations only on the titles. Compared with a previous study in F-pattern (Shrestha and Lenz, 2007), our homepage had a more complex Visual Hierarchy, which could guide users’ attention to areas outside of the pattern found on less Visually complex pages. This study also shows that Visual complexity may affect the effect of task on viewing pattern, and that task has an effect on viewing a page with a more complex Visual Hierarchy. Images of the faces have served as effective entry points, helping users to retrieve the information with fewer fixations. In addition, including images of faces on a homepage can help guide users in viewing and retrieving information adjacent to those images, even when the images are located below the fold of the webpage. Last, creating Visual appeal in central area may be of great importance in creating a favorable aesthetic experience. These results not only have theoretical importance, but also have practical value.
A H Phillips - One of the best experts on this subject based on the ideXlab platform.
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do ads matter an exploration of web search behavior Visual Hierarchy and search engine results pages
Hawaii International Conference on System Sciences, 2013Co-Authors: A H Phillips, Ruijiao Yang, Soussan DjamasbiAbstract:Users tend to ignore advertisements when viewing a web page, however, when searching for a specific product or service, advertisements can be very useful. This exploratory study examines the impact of online advertisements within search results. The findings provide support for the competition for attention theory in that users are looking at advertisements and entries when evaluation SERPs. We also examine web page search behavior and how it can affect user experience. The results show that eye tracking data is valuable for designers, marketers, and usability experts to develop and evaluate web page design.
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HICSS - Do ads matter? An exploration of web search behavior, Visual Hierarchy, and search engine results pages
2013 46th Hawaii International Conference on System Sciences, 2013Co-Authors: A H Phillips, Ruijiao Yang, Soussan DjamasbiAbstract:Users tend to ignore advertisements when viewing a web page, however, when searching for a specific product or service, advertisements can be very useful. This exploratory study examines the impact of online advertisements within search results. The findings provide support for the competition for attention theory in that users are looking at advertisements and entries when evaluation SERPs. We also examine web page search behavior and how it can affect user experience. The results show that eye tracking data is valuable for designers, marketers, and usability experts to develop and evaluate web page design.
