What visual information is used for stereoscopic depth displacement discrimination?

There are two ways to detect a displacement in stereoscopic depth, namely by monitoring the change in disparity over time (CDOT) or by monitoring the inter-ocular velocity difference (IOVD). Though previous studies have attempted to understand which cue is most significant for the visual system, none have designed stimuli that provide a comparison in terms of relative efficiency between them. Here we used two-frame motion and random dot noise to deliver equivalent strengths of CDOT and IOVD information to the visual system. Using three kinds of random dot stimuli, we were able to isolate CDOT or IOVD or deliver both simultaneously. The proportion of dots delivering CDOT or IOVD signals could be varied, and we defined discrimination threshold as the proportion needed to detect the direction of displacement (towards or away)1. Thresholds were similar for stimuli containing CDOT only, and containing both CDOT and IOVD, but only one participant was able to consistently perceive the displacement for stimuli containing only IOVD. We also investigated the effect of disparity pedestals on discrimination. Performance was best when the displacement crossed the reference plane, but was not significantly different for stimuli containing CDOT only, or containing both CDOT and IOVD. When stimuli are specifically designed to provide equivalent two-frame motion or disparity-change, few participants can reliably detect displacement when IOVD is the only cue. This challenges the notion that IOVD is involved in the discrimination of direction of displacement in two-frame motion displays.PreprintPeer reviewe

Two independent mechanisms for motion-in-depth perception : evidence from individual differences

Our forward-facing eyes allow us the advantage of binocular visual information: using the tiny differences between right and left eye views to learn about depth and location in three dimensions. Our visual systems also contain specialized mechanisms to detect motion-in-depth from binocular vision, but the nature of these mechanisms remains controversial. Binocular motion-in-depth perception could theoretically be based on first detecting binocular disparity and then monitoring how it changes over time. The alternative is to monitor the motion in the right and left eye separately and then compare these motion signals. Here we used an individual differences approach to test whether the two sources of information are processed via dissociated mechanisms, and to measure the relative importance of those mechanisms. Our results suggest the existence of two distinct mechanisms, each contributing to the perception of motion-in-depth in most observers. Additionally, for the first time, we demonstrate the relative prevalence of the two mechanisms within a normal population. In general, visual systems appear to rely mostly on the mechanism sensitive to changing binocular disparity, but perception of motion-in-depth is augmented by the presence of a less sensitive mechanism that uses interocular velocity differences. Occasionally, we find observers with the opposite pattern of sensitivity. More generally this work showcases the power of the individual differences approach in studying the functional organization of cognitive systems.Publisher PDFPeer reviewe

Technical Needs Assessment of North Dakota Manufacturers

The problem of this study was to identify, document, and prioritize technical assistance needs of North Dakota manufacturers. The primary objective was to determine the technical assistance needs of North Dakota manufacturers as they relate to: a) education; b) consulting; c) research and development. A secondary objective was to prioritize the ten most pertinent technical areas of need as determined by the North Dakota manufacturers. This study used a descriptive survey research method. The researcher devised a survey instrument and was validated by a panel of experts. The instrument included fifty-three technical areas, most of which are emerging technologies. The questionnaire asked the manufacturers to assess their degree of technical need as it related to education, consulting and research and development. The questionnaire was sent to six hundred seventy North Dakota manufacturers. The study was divided into six sections: (a) devise a survey questionnaire, (b) perform a pilot study, (c) identify the population, (d) collect the data, (e) organize the data, and (f) statistical analysis of the data. Central tendency, standard deviation, rank order, and correlation were the four statistical tests used for analyzing the data The following conclusions were made after the completion of the study: 1) The type of technical assistance most evident was for education. 2) The top ten technical areas correlate closely with technical concepts that are on the cutting edge of technology 3) North Dakota manufacturers are interested in acquiring the information needed to make an informative decision on whether or not to implement these pertinent technologies The following recommendations are offered for further study: 1 . A follow-up study be performed in three years to determine if the technical assistance needs of North Dakota manufacturers have changed. 2. Set-up a program that would allow the manufacturers and the higher education community to accumulate and disseminate information pertinent to their wants and needs. 3. A study that encompasses more of the business and administrative end of manufacturing. 4. Design a study that would continue to acquire information for a manufacturers\u27 database for North Dakota. 5. Conduct a feasibility study to determine the need for a manufacturing extension service in North Dakot

„Вогнехреще” або неологізми як відображення військового протистояння

(uk) У статті здійснено дослідження неологізмів та оказіоналізмів, утворених на фоні суспільно-політичної ситуації в Україні кінця 2013 –початку 2015 року. Увага зосереджена на їхніх семантичних та словотвірних особливостях. Розглянуто вплив екстра- та інтралінгвальних чинників на творення таких лексичних одиниць.(en) The paper studies neologisms and occasionalisms formed on the background of socio-political situation in Ukraine in late 2013 – early 2015. The focus is on their semantic and word-building peculiarities. The influence of extra-and intralinguistic factors on the formation of lexical units is considered

Visual discomfort and depth-of-field

Visual discomfort has been reported for certain visual stimuli and under particular viewing conditions, such as stereoscopic viewing. In stereoscopic viewing, visual discomfort can be caused by a conflict between accommodation and convergence cues that may specify different distances in depth. Earlier research has shown that depth-of-field, which is the distance range in depth in the scene that is perceived to be sharp, influences both the perception of egocentric distance to the focal plane, and the distance range in depth between objects in the scene. Because depth-of-field may also be in conflict with convergence and the accommodative state of the eyes, we raised the question of whether depth-of-field affects discomfort when viewing stereoscopic photographs. The first experiment assessed whether discomfort increases when depth-of-field is in conflict with coherent accommodation-convergence cues to distance in depth. The second experiment assessed whether depth-of-field influences discomfort from a pre-existing accommodation-convergence conflict. Results showed no effect of depth-of-field on visual discomfort. These results suggest therefore that depth-of-field can be used as a cue to depth without inducing discomfort in the viewer, even when cue conflicts are large. © 2013 L O'Hare, T Zhang, H T Nefs, P B Hibbard

The hunt for red dwarf binaries and hot planets in the WFCAM transit survey

Red Dwarfs are at the heart of Astronomy because they are the most abundant type of star that we know of in our Galaxy. Yet, surprisingly little is known about their formation, evolution and the nature of their companions. In this thesis I present the first results of the WFCAM Transit Survey, a unique long-time monitoring program of many thousands of red dwarfs in the infrared, where they are the brightest. By studying their properties in eclipsing binary systems it is shown that red dwarfs are of great value to simulations of low-mass star formation, binary dynamics, stellar structure and ultimately the fundamental properties of Earth-like planets.Interstellar matter and star formatio

Psychological risk factors of micro- and macrovascular outcomes in primary care patients with type 2 diabetes:Rationale and design of the DiaDDZoB Study

BACKGROUND: Depression is a common psychiatric complication of diabetes, but little is known about the natural course and the consequences of depressive symptoms in primary care patients with type 2 diabetes. While depression has been related to poor glycemic control and increased risk for macrovascular disease, its association with microvascular complications remains understudied. The predictive role of other psychological risk factors such as Type D (distressed) personality and the mechanisms that possibly link depression and Type D personality with poor vascular outcomes are also still unclear. METHODS/DESIGN: This prospective cohort study will examine: (1) the course of depressive symptoms in primary care patients with type 2 diabetes; (2) whether depressive symptoms and Type D personality are associated with the development of microvascular and/or macrovascular complications and with the risk of all-cause or vascular mortality; and (3) the behavioral and physiological mechanisms that may mediate these associations. The DiaDDZoB Study is embedded within the larger DIAZOB Primary Care Diabetes study, which covers a comprehensive cohort of type 2 diabetes patients treated by over 200 primary care physicians in South-East Brabant, The Netherlands. These patients will be followed during their lifetime and are assessed annually for demographic, clinical, lifestyle and psychosocial factors. Measurements include an interviewer-administered and self-report questionnaire, regular care laboratory tests and physical examinations, and pharmacy medication records. The DiaDDZoB Study uses data that have been collected during the original baseline assessment in 2005 (M(0); N = 2,460) and the 2007 (M(1); N = 2,225) and 2008 (M(2); N = 2,032) follow-up assessments. DISCUSSION: The DiaDDZoB Study is expected to contribute to the current understanding of the course of depression in primary care patients with type 2 diabetes and will also test whether depressed patients or those with Type D personality are at increased risk for (further) development of micro- and cardiovascular disease. More knowledge about the mechanisms behind this association is needed to guide new intervention studies

The effect of motion on the perception of material appearance

We analyze the effect of motion in the perception of material appearance. First, we create a set of stimuli containing 72 realistic materials, rendered with varying degrees of linear motion blur. Then we launch a large-scale study on Mechanical Turk to rate a given set of perceptual attributes, such as brightness, roughness, or the perceived strength of reflections. Our statistical analysis shows that certain attributes undergo a significant change, varying appearance perception under motion. In addition, we further investigate the perception of brightness, for the particular cases of rubber and plastic materials. We create new stimuli, with ten different luminance levels and seven motion degrees. We launch a new user study to retrieve their perceived brightness. From the users'' judgements, we build two-dimensional maps showing how perceived brightness varies as a function of the luminance and motion of the material