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In this issue of Neuron, Jordan and Keller (2020) explore subthreshold computations underlying predictive coding using whole-cell recordings in mouse visual cortex. Their findings suggest that layer 2/3, but not layer 5/6, neurons compute prediction errors by subtracting predicted and actual visual flow inputs generated by locomotion.

Sensory experience is often dependent on one’s own actions, including self-motion. Theories of predictive coding postulate that actions are regulated by calculating prediction error, which is the difference between sensory experience and expectation based on self-generated actions. Signals consistent with prediction error have been reported in mouse visual cortex (V1) when visual flow coupled to running is unexpectedly perturbed. Here, we show that such signals can be elicited by visual stimuli uncoupled with the animal’s running. We recorded the activity of mouse V1 neurons while presenting drifting gratings that unexpectedly stopped. We found strong responses to visual perturbations, which were enhanced during running. If these perturbation responses are signals about sensorimotor mismatch, they should be largest for front-to-back visual flow expected from the animals’ running. Responses, however, did not show a bias for front-to-back visual flow. Instead, perturbation responses were strongest in the preferred orientation of individual neurons and perturbation responsive neurons were more likely to prefer slow visual speeds. Our results therefore indicate that prediction error signals can be explained by the convergence of known motor and sensory signals in visual cortex, providing a purely sensory and motor explanation for purported mismatch signals.

Virtual reality (VR) technology combined with exercise, called VR exercise, is believed to have beneficial effects on mood; but VR factors contributing to improved mood remain ambiguous. The purpose of this study was to examine the effect of visual flow speed on psychophysiological responses (i.e., physiological responses, ratings of perceived exertion or RPE, and mood) to immersive VR exercise in a simulated natural environment. Eighteen male participants ( Mage =23.1, SD = 1.9 years) cycled an ergometer at 80 watts for 5 minutes on three separate occasions while watching a first-person VR movie through VR goggles at three different speeds of visual flow, corresponding to 7.5 km.h−1, 15 km.h−1, and 22.5 km.h−1. The order of the three speeds was randomized in a counterbalanced design. We measured heart rate, oxygen uptake, minute ventilation, respiratory rate, and cadence during the exercise, and we recorded ratings of perceived exertion (RPE) and mood immediately after the exercise. We evaluated mood states with the Two-Dimensional Mood Scale. One-way repeated measures analysis of variance or the Friedman test revealed no significant effects on any physiological variables, RPE or cadence as a result of altered visual flow speed during VR exercise ( p > .05). However, speed of visual flow significantly influenced participant ratings of Vitality ( p = 0.01) and Pleasure ( p = 0.02), with the faster speed resulting in a more positive mood state. As these findings showed that VR exercise with faster visual flow induced positive mood states, we recommend faster visual flow to induce better mood states in VR exercise.

Interface modules are defined by the concept of modularity according to the characteristics of mobile App interface. A modular design model containing five steps (namely: refine, prioritize, assemble, change, and select) is constructed. The proposed model feasibility is verified by its application to streamline the design of the mobile App interface with the multi-directional user experience features.

Summary Sensory experience often depends on one’s own actions, including self-motion. Theories of predictive coding postulate that actions are regulated by calculating prediction error, which is the difference between sensory experience and expectation based on self-generated actions. Signals consistent with prediction error have been reported in the mouse visual cortex (V1) when visual flow coupled to running was unexpectedly stopped. Here, we show that such signals can be elicited by visual stimuli uncoupled to an animal running. We record V1 neurons while presenting drifting gratings that unexpectedly stop. We find strong responses to visual perturbations, which are enhanced during running. Perturbation responses are strongest in the preferred orientation of individual neurons, and perturbation-responsive neurons are more likely to prefer slow visual speeds. Our results indicate that prediction error signals can be explained by the convergence of known motor and sensory signals, providing a purely sensory and motor explanation for purported mismatch signals., Graphical abstract, Highlights • Mouse primary visual cortex neurons respond to perturbations of visual flow • Perturbation responses are enhanced by running • Perturbation responses are stronger in the preferred orientation of the neurons • Perturbation-responsive neurons are tuned to slow visual speeds, Muzzu and Saleem find neurons in the mouse visual cortex responding to stops or perturbations of open-loop visual flow. Perturbation responses are enhanced by running, and responsive neurons prefer low visual speeds. These results suggest concurrent selectivity for low visual speeds and running can explain sensorimotor mismatch signals in the visual cortex.

Visual flow is used to perceive and regulate movement speed during locomotion. We assessed the extent to which variation in flow from the ground plane, arising from static visual textures, influences locomotion speed under conditions of concurrent perceptual load. In two experiments, participants walked over a 12-m projected walkway that consisted of stripes that were oriented orthogonal to the walking direction. In the critical conditions, the frequency of the stripes increased or decreased. We observed small, but consistent effects on walking speed, so that participants were walking slower when the frequency increased compared to when the frequency decreased. This basic effect suggests that participants interpreted the change in visual flow in these conditions as at least partly due to a change in their own movement speed, and counteracted such a change by speeding up or slowing down. Critically, these effects were magnified under conditions of low perceptual load and a locus of attention near the ground plane. Our findings suggest that the contribution of vision in the control of ongoing locomotion is relatively fluid and dependent on ongoing perceptual (and perhaps more generally cognitive) task demands. Electronic supplementary material The online version of this article (10.3758/s13414-017-1417-3) contains supplementary material, which is available to authorized users.

A novel visual flow-through column biomimetic immunoassay using horseradish peroxidase-labeled clenbuterol (HRP-CLB) as a tracer and molecularly imprinted polymers (MIPs) with high specificity as the artificial antibody has been developed for rapid detection of CLB. Different intensities of blue color products on test layer of the column could be observed after reaction. This optimized assay provided a preliminary qualitative result in the concentration range of 0 to 1000 μg/L by judging color density of the test layer without any equipment, and the detection could be finished within 15 min. This assay was evaluated using CLB spiked water samples and results were comparable to high performance liquid chromatography method. The visual detection limit of 5 μg/L in water sample was obtained. This developed flow-through column biomimetic immunoassay was demonstrated as a suitable tool for rapid, sensitive, low-cost, and qualitative determination of CLB residues on site.

Hydrate blockages impose a serious flow assurance problem on gas transportation pipelines. Regular inspections for the formation of hydrate blockages are imperative along with the use of an effective blockage removal method. In this study, the processes of hydrate blockage formation and removal were investigated using a fully visual flow loop. Comprehensive analysis of the pressure drop was performed along with a discussion of the acquired visual images of the hydrates to describe the phenomena. Hydrate blockage first occurred in no through-flow zone of the pipeline, specifically in deadleg. The results showed that higher LL (liquid loading: the initial liquid volume fraction) caused a blockage in the inlet, while lower LL caused a faster and more widespread blockage. Moreover, shut-in and restart operations also caused blockages due to the temperature decrease and annealing of hydrate. The experiments showed that blockages formed more quickly as a result of lower LL during the shut-in operation. This necessitated the reduction of shut-in duration and maintenance of the temperature at phase equilibrium condition. In addition, the depressurization method was used to decompose bulk hydrate in order to remove the blockage. The results confirmed that stepwise depressurization could be applied to prevent hydrate reformation at a higher LL and water conversion rate, while a lower backpressure could be used at lower LL to efficiently remove blockages.

فى مجال الفنون البصريه للتکوين دور بارز و اساسى و بناءي و فعال لکل الوان الفنون البصريه. فهو عملية تنظيمالعناصر البصريه داخل المساحة التصميمية بشکل سليم و مدروس. ولما کان فن تصميم الاعلان احد ابرز هذه الفنونالبصرية فى العصر الحالى و الذى يعتمد فى الاساس على توصيل رسالة ما لمجموعة من المتلقين المستهدفين بشکلمدروس و جذاب قائم على تکوين قوى وذلک لتحقيق الهدف الاساسى من الاعلان و هو جذب انتباه و اثارة الاهتمامالمتلقين.لذا يعد التکوين فى حد ذاته فنا له دور اساسى فى مجال تصميم الاعلان لانه المهاره التى بواسطتها يقوم المصممبتوزيع العناصر التصميميه داخل مساحة التصميم ليس فقط بشکل جذاب يلفت انتباه المتلقى و انما بتخطيط مدروس يقومبتوجيه اعين المتلقين داخل مساحة التصميم حتى يضمن وصول مضمون الرسالة الاعلانيه کاملة .يهتم البحث بدراسة مفهوم التکوين فى تصميم الاعلان و دوره الاساسى فيه . ثم يستعرض عناصر اللغه البصريهللتصميم و منها الى اهم مبادىء و اساسيات التصميم وصولا الى القواعد التى تحکم عملية التکوين الفنى فى الاعلان ومجموعة من تقنيات تحقيق التکوين الناجح من خلال استعراض ل نماذج اعلانيه عالميه مختاره تحققت فيها تلک القواعدولاقت نجاحا کبيرا لدى المتلقين.من ابرز نتائج البحث : ان التکوين هو فن مستقل فى حد ذاته و له دور اساسى فيه و لاتقوم للعمليه التصميميه الناجحه قائمه بدونه.کلما کان التکوين فى تصميم الاعلان مدروسا و قويا ادى ذلک الى وصول مضمون الاعلان بکفاءه اکبر للمتلقين.ان فن التکوين فى تصميم الاعلان يقوم فى الاساس على الفهم العميق من قبل مصمم الاعلان للمضون الخاص بالرسالهالعلانيه حتى يتمکن من توظيف فن التکوين فى اختيار العناصر التى تتناسب معها و ان يحسن ترتيبها و توزيعها داخلالمساحة

New research identifies a frontal area in the mouse neocortex that sends predictions of locomotion-coupled visual flow to visual cortex. The findings support predictive coding theories of cortical processing.

All Smartphones have become a necessity rather than a utility. Not a single person can deny that our mobile phones go wherever we go. Phones were created as a means for more accessible communication over distance. The purpose of a phone has dramatically changed over the years by the technology advancement and the arrival of smartphones which provides many applications and make us stick to it. This study understands the correlation between the activity of eyes and flow level of the eye. Also, how the visual activity parameters are calculated will be discussed. This study enhances the understanding of visual fatigue caused due to the digital medium. Examine the subject’s eye flow level with smartphone and VDT utilisation. Besides, the application of learning algorithms, including machine learning/deep learning is massive with regards to analysing visual fatigue. The purpose of this study also going to discuss the application of both machine learning and deep learning on analysing visual fatigue caused by Digital Medium.

Compensation for wind drift in relation to the side-wind velocity and altitude was investigated in Song Thrushes during autumn migration. The birds were recorded at night flying above the prominent leading line of a marine spit which coincided with the general direction of their migration. Among the large size passerine species, Song Thrushes were identified by a combination of five flight characteristics typical only of this species during particular periods of autumn. The thrushes showed different reactions to the crosswinds: complete and partial compensation for the displacement and drift. Under normal visibility, the completeness of compensation depended both on the velocity of the side-wind and altitude. The degree of compensation achieved was reduced with an increase of altitude, regardless of the wind. Under the same wind conditions, the angle of drift (the angle between the track direction and the leading line) increased with altitude, but the number of birds that compensated for drift decreased. On average, at heights below 300 m agl, the thrushes were capable of compensating completely for moderate winds; between 300 and 600 m agl compensation was partial; but above 600 m the birds drifted completely. Birds of the same species flying above the same terrain may demonstrate different reactions to the same crosswind depending on altitude. Meanwhile, flight tracks gradually deviated from the leading line with an increase in altitude, the headings of the birds got closer to the general migratory direction. It is more likely that the birds control displacement using the visual flow regulation principle by the angular velocity of the landmarks below them running aside in relation to their flight direction, which is inversely proportional to the altitude. Low flying thrushes promptly reacted to the shifting of the leading line of the spit with an average angular velocity of more than 0.8°/s perpendicular to the direction of flight and compensated completely for drift. Shifting of the leading line with an angular velocity of less than 0.4°/s, the high flying birds did not seem to notice or did not try to compensate for displacement deliberately.

Emaki is a traditional Japanese pictorial expression format. Emaki (“picture scrolls”) are viewed using the unique characteristics of scrolls. The viewer does not look at the paintings from the start to the end, but rather reveals them gradually by unravelling the scroll. Emaki content can be broadly categorized into two types: narrative emaki and religious emaki. Kasuga Gongen Genki and Ishiyama-dera Engi, the subjects of this analysis, are religious emaki from the Kamakura Period, during which the emaki culture developed and a diverse range of works were produced. These emaki are attributed to Takashina Takakane, a renowned and greatly talented imperial court artist. These emaki include many scenes depicting backgrounds with shrines, temples, residences, and other buildings in oblique projections. Accordingly, the front, sides, and top are drawn for sections with buildings, and the characters in the narrative are placed on one of these three locations. As a result, one gets a glimpse of regularity (although it is partial) in the order by which the building compositions change and in the order of viewing the scrolls. Emaki are viewed using the unique method of looking at the sections that are unrolled in order. It is thought that artists did not just depict buildings in a typical fashion, but intentionally repeated character placements and compositions to create a visual flow for the viewer. Contemporary viewers were limited to members of the noble class, and this culture of visual experience was cultivated to satisfy their needs.

Statistical analysis is a frequent task in several research fields such as HCI, Psychology, and Medicine. Performing statistical analysis using traditional textual programming languages like R is considered to have several advantages over GUI applications like SPSS. However, our examination of 40 analysis scripts written using current IDEs for R shows that such scripts are hard to understand and maintain, limiting their replication. We present StatWire, an IDE for R that closely integrates the traditional text-based editor with a visual data flow editor to better support statistical programming. A preliminary evaluation with four R users indicates that this hybrid approach could result in statistical programming that is more understandable and efficient.

Grids, matrices, and tables are commonly used to organize information. A number of design techniques and psychological principles address how viewers’ eyes can be guided through a visual work. Designers refer to such objectives as "creating visual flow." One common technique, “zebra-shading,” is intended to guide eyes through the grid by alternating shaded and unshaded rows or columns. However, the effects of these manipulations have largely not been explored experimentally. We will review the techniques designers use to guide the eyes of their audience, associated psychological foundations, and outline some research done on the graphic design of a specific type of grid: tables. Then, we will describe an experiment wherein participants conducted a visual search task in grids with different shading manipulations. The analysis showed data trending toward improved response time when the target followed the shading.

When a behavior repeatedly fails to achieve its goal, animals often give up and become passive, which can be strategic for preserving energy or regrouping between attempts. It is unknown how the brain identifies behavioral failures and mediates this behavioral-state switch. In larval zebrafish swimming in virtual reality, visual feedback can be withheld so that swim attempts fail to trigger expected visual flow. After tens of seconds of such motor futility, animals became passive for similar durations. Whole-brain calcium imaging revealed noradrenergic neurons that responded specifically to failed swim attempts and radial astrocytes whose calcium levels accumulated with increasing numbers of failed attempts. Using cell ablation and optogenetic or chemogenetic activation, we found that noradrenergic neurons progressively activated brainstem radial astrocytes, which then suppressed swimming. Thus, radial astrocytes perform a computation critical for behavior: they accumulate evidence that current actions are ineffective and consequently drive changes in behavioral states. VIDEO ABSTRACT.

Male moths locate conspecific females by pheromone-induced upwind flight maintained by detecting a visual flow, termed optomotor anemotaxis. Their behavioural pattern is characterized by an upwind surge in response to a pheromone stimulus and crosswind casting after odour loss, which is considered to be reset and restarted on receipt of another pheromone pulse. However, pheromone-stimulated males of the potato tuberworm moth Phthorimaea operculella exhibit a series of short and straight intermittent flights, or hops, when moving upwind. It is unclear whether they navigate by employing the same behavioural pattern and wind detection mechanism as that used by flying moths. To analyze odour-modulated anemotaxis in male potato tuberworm moths, a flat wind tunnel is constructed to give regular odour stimuli to an insect regardless of its location. Moths are subjected to pheromone pulses of different frequencies to test whether they show a behavioural pattern that is reset and restarted by a pheromone pulse. Moths on the ground are also subjected to crosswind shear to examine their detection of wind direction. Path analyses reveal that males surge upwind when they receive a pheromone pulse and exhibit casting by successive hops when they lose odour. This behavioural pattern appears to be similar to that of flying moths. When the direction of the airflow is switched orthogonally, males adjust their course angle accordingly when they are on the ground. It is suggested that, instead of optomotor anemotaxis, this ‘aim-then-shoot’ system aids the detection of wind direction, possibly by mechanosensory means.

Our objective was to assess the influence of visual flow direction on physiological changes and symptoms elicited by cybersickness. Twelve healthy subjects (6 male and 6 female) were exposed to a 15-min virtual ride on a rollercoaster on two different days in a counterbalanced manner, such half of participants were facing forward during the first ride while another half was facing backward. Forehead skin conductance, heart rate and HRV parameters (SDRR, RMSSD) were collected as objective measures; subjective symptoms were assessed with the Motion Sickness Assessment Questioner immediately after exposure. We found that while nausea ratings at which participants terminated the experiment did not differ between forward/backward rides, the mean ride tolerance time was significantly longer during reverse ride compared to forward ride (6.1±0.4 vs 5.0±0.5 min, respectively, p = 0.01, η2 = 0.45). Analysis of HRV parameters revealed significant reduction in both RMSSD (p = 0.02, t = 2.62, η2 = 0.43) and SDRR (p = 0.01, t = 2.90, η2 = 0.45) in the forward ride; no such changes were found in the backward ride. We also found that amplitude of phasic changes in forehead skin conductance increased significantly in both ride directions. This increase however was significantly lower (p

In the context of the perceptual changes of this Century, the digital culture has challenged the reason of being of the paragraph as a graphic unity of meaning.The elements that define it, such as the segmentation of a discernible and perceived totality, the organization of the content according to a linear mode and the possibility of reading in a progressive way from a starting point to a more elaborated and following one, coexist nowadays with new expressive demands. In the absence of thepossibility to conceive a textual totality in the current technological scenarios, we are seeing the emergence and exploration of other type of organizations which free the visual flow and allow it to acquire more flexibility (depending of the medium involved). From the expression ‘the death of the paragraph’, taken from a survey made to intellectuals regarding the most important changes occurred in the XX Century, it willbe analyzed the trajectory of the Western writing since de Middle Ages to the contemporary forms of textual organizations, in which the Discourse it is fragmented indynamics that make unnecessary (and impossible) the use of paragraphs. En el contexto de los cambios perceptuales propios de este siglo, la digitalidad ha puesto en jaque la razón de ser del párrafo como unidad gráfica de sentido. Los elementos que lo definen – segmentación de un todo perceptible, ordenación del contenido según un hilo, progresión de lectura desde un punto de partida a otro más elaborado – coexisten ahora con nuevas exigencias expresivas. Ante la imposibilidad de concebir un todo textual asistimos al surgimiento y exploración de otras organizaciones que liberan el flujo visual, que lo vuelven flexible, acorde a la flexibilidad del soporte. A partir de la expresión ‘la muerte del párrafo’ tomada de una encuesta realizada a intelectuales acerca de los mayores cambios ocurridos en el siglo XX se analizará el devenir de la escritura occidental desde el Medioevo hasta losnuevos modos de organización textual en las que el discurso se atomiza en derivas que hacen innecesario (e imposible) al párrafo.

Children’s (3–5 years) and adults’ postural reactions to different conditions of visual flow information varying in its frequency content was examined using a moving room apparatus. Both groups experienced four conditions of visual input: low-frequency (0.20 Hz) visual oscillations, high-frequency (0.60 Hz) oscillations, multifrequency nonpredictable visual input, and no imposed visual information. Analyses of the frequency content of anterior–posterior (AP) sway revealed that postural reactions to the single-frequency conditions replicated previous findings; children were responsive to low- and high-frequency oscillations, whereas adults were responsive to low-frequency information. Extending previous work, AP sway in response to the nonpredictable condition revealed that both groups were responsive to the different components contained in the multifrequency visual information, although adults retained their frequency selectivity to low-frequency versus high-frequency content. These findings are discussed in relation to work examining feedback versus feedforward control of posture, and the reweighting of sensory inputs for postural control, as a function of development and task context.

The purpose of this study was to evaluate the effects of a visual flow speed‘s modulation-based VR(virtual reality) program on gait function in stroke patients. Thirty one stroke patients were randomly selected at Dep. of Rehabilitation medicine of M hospital in Seoul. We carried out the gait analysis by dividing them with four conditions : one condition had applied without the visual flow modulation-based VR and another had done three visual flow speed's modulation-based VR(0.25, 1, 2 times). The gait analysis was used with GaitRite system. The data were collected using gait velocity, cadence, stride length, step length, single support time, and double support time during treatment. The results were as follows. First, the slow visual flow(0.25 times)-based VR program on the condition was significant decrease gait velocity, cadence, stride length, step length and increase single support time, double support time(p

Although there is much research on infants' ability to orient in space, little is known regarding the information they use to do so. This research uses a rotating room to evaluate the relative contribution of visual and vestibular information to location of a target following bodily rotation. Adults responded precisely on the basis of visual flow information. Seven-month-olds responded mostly on the basis of visual flow, whereas 9-month-olds responded mostly on the basis of vestibular information, and 12-month-olds responded mostly on the basis of visual information. Unlike adults, infants of all ages showed partial influence by both modalities. Additionally, 7-month-olds were capable of using vestibular information when there was no visual information for movement or stability, and 9-month-olds still relied on vestibular information when visual information was enhanced. These results are discussed in the context of neuroscientific evidence regarding visual-vestibular interaction, and in relation to possible changes in reliance on visual and vestibular information following acquisition of locomotion.

Saccades shift the gaze rapidly every few hundred milliseconds from one fixated location to the next, producing a flow of visual input into the visual system even in the absence of changes in the environment. During fixation, small saccades called microsaccades are produced 1-3 times per second, generating a flow of visual input. The characteristics of this visual flow are determined by the timings of the saccades and by the characteristics of the visual stimuli on which they are performed. Previous models of microsaccade generation have accounted for the effects of external stimulation on the production of microsaccades, but they have not considered the effects of the prolonged background stimulus on which microsaccades are performed. The effects of this stimulus on the process of microsaccade generation could be sustained, following its prolonged presentation, or transient, through the visual transients produced by the microsaccades themselves. In four experiments, we varied the properties of the constant displays and examined the resulting modulation of microsaccade properties: their sizes, their timings, and the correlations between properties of consecutive microsaccades. Findings show that displays of higher spatial frequency and contrast produce smaller microsaccades and longer minimal intervals between consecutive microsaccades; and smaller microsaccades are followed by smaller and delayed microsaccades. We explain these findings in light of previous models and suggest a conceptual model by which both sustained and transient effects of the stimulus have central roles in determining the generation of microsaccades.

Aiming to ascertain basic display guidelines for improved support of pilot spatial orientation (SO), the visual resonance with the perceptual mechanism for SO was explored in 2 experiments. Postural responses indicated the efficiency of visual cues to control proprioception and equilibrium sense. A display design is suggested that integrates the results with the concepts for an operational head-up display symbology. By means of improved perception of integrated pitch, roll, and yaw information and resonance of synthetic visual flow with the SO mechanism, the design may in the future contribute to combatting pilot spatial disorientation.

This study tested the effects of a motion-coupled display on task performance and self-reports of motion sickness for subjects experiencing motion at a frequency and intensity previously found to be nauseogenic. Subjects were randomly assigned to a control condition or a treatment condition. Both groups performed a simple computer game (Tetris) for a 30-minute period while moving forward and backward at 0.2 Hz in an enclosed chamber. In the treatment condition, a visual flow field whose movement was coupled to the motion of the enclosed test chamber was displayed behind and around a window in which subjects performed the computer game. For the control condition, the visual flow field elements were kept stationary. Contrary to expectations, no differences were found between the two groups on self-reported motion sickness symptoms; however, the treatment group performed significantly better than the control group on the computer game.

When we move, the visual world moves toward us. That is, self-motion normally produces visual signals (flow) that tell us about our own motion. But these signals are distorted by our motion: Visual flow actually appears slower while we are moving than it does when we are stationary and our surroundings move past us. Although for many years these kinds of distortions have been interpreted as a suppression of flow to promote the perception of a stable world, current research has shown that these shifts in perceived visual speed may have an important function in measuring our own self-motion. Specifically, by slowing down the apparent rate of visual flow during self-motion, our visual system is able to perceive differences between actual and expected flow more precisely. This is useful in the control of action.

Head-bobbing is a common and characteristic behavior of walking birds. While the activity could have a relatively minor biomechanical function, for balance and stabilization of gait, head-bobbing is thought to be primarily a visual behavior in which fixation of gaze alternates with a forward movement that generates visual flow. We studied head-bobbing in locomoting whooping cranes (Grus americana) and sandhill cranes (Grus canadensis), using food strewn on the ground to motivate them to walk or run. When the cranes walked, head-bobbing proceeded in a four-step sequence that was closely linked to the stepping cycle. The time available for gaze stabilization decreased with travel speed, and running cranes did not head-bob at all. As a crane extended its bill towards the ground for food, it also exhibited a series of short head-bobs that were not associated with forward travel. Head-bobbing is a flexible behavior that varies with gait and with visual search, most notably as the cranes prepare to strike with the bill.

We introduce a novel tool for visualizing netflow traffic on enterprise networks called 3D Parallel Coordinate Planes (3DPCP). This tool provides operators with the ability to manipulate the visual flow of network traffic information by arranging two-dimensional planes along a vertical time axis in 3D space.

In order to investigate level of experienced sickness symptoms in a VR based air combat simulator, a combined methodology was used. Before, during, and after simulation the participants repeatedly answered a VR sickness symptoms questionnaire (VRSQ). In addition, before and after simulation their postural stability was measured. In order to investigate if measurements of postural stability can be made more sensitive to changes in postural stability, during the measurements a sideways rolling wide angular visual flow was presented to half of the participants. Only low levels of VR-sickness symptoms and effects on postural stability were found. However, headache caused by the Head Mounted Display was a major concern for most participants. The presentation of a visual flow during the measurements of postural stability led to generally higher levels of postural instability, but did not increase the sensitivity of the measurements.

Scientific visualization is widely used for the analysis of datasets obtained from measurements and numerical simulations. However, scientists and engineers are not always visualization experts who are familiar with how to map their numerical data to proper graphical primitives to yield optimal visualization. Therefore, we have built on modular visualization environments (MVEs) to develop a design support system, called GADGET, for scientific visualization applications. In this paper, we attempt to reexamine specifications for design directives to make the GADGET system tailored to visual flow data mining.

Despite considerable efforts to diminish critical spatial disorientation incidents during flight, they persist at constant rate. In instrument meteorological conditions, significantly enhanced support of spatial orientation (SO) could be achieved by displays of peripheral visual flow with conformal horizon. Focused depth related effectiveness of peripheral visual flow needs however to be investigated because of the pilot is changing depth focus in the cockpit. This was investigated in two experiments by manipulating relative depths of peripheral/central presentations and measuring their effects on postural instability. The results show that focused depth close-by with peripheral displays further away have less impact on perceived SO than focusing further away with peripheral displays closer. We conclude that focused depth drives the effects of peripheral visual flow on SO, and implementation implications are shortly discussed.

Humans have a limitation in the information flow that can process. This article sumarizes the main biological sources of this limitation and make some reflexions over the impact on the interaction with computers in order to prevent an ergonomic design.

Although dopaminergic replacement therapy is believed to improve sensory processing in PD, while delayed perceptual speed is thought to be caused by a predominantly cholinergic deficit, it is unclear whether sensory-perceptual deficits are a result of corrupt sensory processing, or a delay in updating perceived feedback during movement. The current study aimed to examine these two hypotheses by manipulating visual flow speed and dopaminergic medication to examine which influenced distance estimation in PD. Fourteen PD and sixteen HC participants were instructed to estimate the distance of a remembered target by walking to the position the target formerly occupied. This task was completed in virtual reality in order to manipulate the visual flow (VF) speed in real time. Three conditions were carried out: (1) BASELINE: VF speed was equal to participants’ real-time movement speed; (2) SLOW: VF speed was reduced by 50 %; (2) FAST: VF speed was increased by 30 %. Individuals with PD performed the experiment in their ON and OFF state. PD demonstrated significantly greater judgement error during BASELINE and FAST conditions compared to HC, although PD did not improve their judgement error during the SLOW condition. Additionally, PD had greater variable error during baseline compared to HC; however, during the SLOW conditions, PD had significantly less variable error compared to baseline and similar variable error to HC participants. Overall, dopaminergic medication did not significantly influence judgement error. Therefore, these results suggest that corrupt processing of sensory information is the main contributor to sensory-perceptual deficits during movement in PD rather than delayed updating of sensory feedback.

Foraging honeybees find their way from their hive to their food in a stereotypical manner using up to four place-finding servomechanisms in sequence: (1) They first fly a vector (straight-line distance and direction) from their home to the vicinity of the target. Direction is determined by the sun compass and by distant landmarks, while distance is estimated by visual flow. (2) They then beacon in on a landmark near the target location. (3) En route toward the landmark, they may adopt a sensorimotor trajectory that takes them toward the target. (4) Near the expected target location, they attempt image matching, which involves trying to put surrounding landmarks at the correct positions on their eyes. In doing image matching, they fly facing a stereotypical direction, a strategy that makes it unnecessary to translate retinal coordinates into another coordinate system.

The effect of different wind speeds on take-off and flight orientation of the sweetpotato whitefly, Bemisia tabaci Gennadius (Homoptera: Aleyrodidae), was studied in the presence of a green visual stimulus which reflected 550 ± 10 nm light, or a white stimulus of the same intensity. When the white light was present, take-off was negatively correlated with wind speed. Analysis of the flight tracks of whiteflies in 0, 15 and 30 cm/s wind with the white light present showed that flight was not directed toward the stimulus in zero wind, and that insects were carried downwind as the wind increased. Net displacement downwind was significantly slower than the wind speed, indicating that B. tabaci can control its rate of displacement relative to its surroundings, and is not always passively transported by the wind. In the presence of the green visual stimulus, take-off and flight behaviour of B. tabaci was markedly different to that observed in the presence of the white light. Taking off was more likely and whiteflies made upwind orientated flights, landing on the illuminated section of the screen when it reflected green light. At all wind speeds tested, the mean ground speeds of B. tabaci were approximately 20 cm/s whether the insects were flying upwind or downwind. This uniformity of ground speed regardless of the changing effects of wind-induced drift in different directions strongly suggests that whiteflies actively control their ground speed using visual flow fields in a manner similar to all other flying insects examined thus far.

We studied the effects of visual scenery modulation related to path inclination on gait performance. So far, seven young healthy adults were tested with an advanced virtual reality (VR) system. While walking on treadmill in a self-paced mode in straight, uphill and downhill inclinations, the subjects were exposed to visual scenery providing visual flow presenting either conflicting or matching visual inclination to the treadmill inclination. When visual scenery changed to uphill or downhill scenery, gait was immediately affected, even when no corresponding treadmill inclination. Further research is required to understand if this effect can be employed to facilitate rehabilitation programs.

This paper provide a physically-Based framework for simulating the ground effect phenomena concerning helicopter hover between objects and the surrounding air. A simplified visual flow model including copters position and aircraft shape was introduced between the helicopter rotors and the ground. By using particle system to simulate the ground effect model, in comprehensive consideration of the authenticity of the visual simulation and the simulation performance, and other factors, we have successfully improved reality and enhanced immersion of the aircraft virtual simulation.

We employed a virtual environment to examine the postural behaviors of adults with cerebral palsy (CP). Four adults with CP (22-32 years) and nine healthy adults (21-27 years) were tested with a Rod and Frame protocol. They then stood quietly on a platform within a three-wall virtual environment. The platform was either kept stationary or tilted 3(°) into dorsiflexion in the dark or with pitch up and down visual field rotations at 30(°)/s and 45(°)/s. While the visual field rotated, the platform was held tilted for 30 s and then slowly returned to a neutral position over 30 s. Center of pressure (CoP) was recorded and center of mass (CoM) as well as trunk and ankle angles were calculated. Electromyography (EMG) responses of the ankle and the hip muscles were recorded and analyzed using wavelets. Larger angular deviations from vertical and horizontal in the Rod and Frame test indicated that adults with CP were more visually dependent than healthy adults. Adults with CP had difficulty maintaining balance when standing on a stationary platform during pitch upward rotation of the visual scene. When the platform was tilted during visual field rotations, adults with CP took longer to stabilize their posture and had larger CoM oscillations than when in the dark. The inability to compensate for busy visual environments could impede maintenance of functional locomotion in adults with CP. Employing a visual field stimulus for assessment and training of postural behaviors would be more meaningful than testing in the dark.

Eye and head tracking of an oscillating visual flow was studied in 1-, 2-, and 3-month-old infants using EOG and an opto-electronic system. A pronounced decrease in phaselag of gaze velocity was observed over this age period, from 170 to 70 msec, but gain changed only marginally. Latency of the onset of tracking decreased with age from 860 to 560 msec. During tracking, the velocity of the head showed high frequency components in the 1–6 Hz range, to which the eye movements were reciprocal and without systematic phase lag. This coordination improved with age.

Purpose This study examined the effect of combined sensory enhancements and manual assistance on the immediate motor responsiveness of infants with spina bifida during treadmill trials. Methods Six infants with spina bifida, aged 4 to 9.5 months, with lesion levels ranging from L4 to S3 were tested in each of 3 randomly ordered sets of enhanced sensory conditions across 3 weekly visits to the laboratory. Sensory enhancements included visual flow, unloading, load, and friction, presented in single and combined applications, as well as a set of trials with manual assistance for stepping at 2 treadmill belt speeds. Dependent variables included step frequencies and overall infant activity. Results Friction+load was the most salient of the contextual sensory enhancements. Manual assistance at the slower speed was also effective at increasing infant stepping. Conclusions Sensory enhancements that increase stance excursion and vertical clearance during swing need further study.

It’s safe to say that many of us began astrophotography feeling overwhelmed by the unnerving task of creating even the simplest astro image. Typically those first successful images were met with a healthy dose of humility as we began to understand the reality of assembling an aesthetically pleasing astronomical image. As we acquired more experience and gradually mastered the fundamentals of image processing our goals and objectives likely evolved and matured.

Whenever we move, we gain experience with how changes in visual flow are related to movement through the environment. One way that researchers have studied these perception-action linkages is through perturbing the normal relationship between perception and action [Kunz et al. 2009; Rieser et al. 1995]. In these studies, people experience an optic flow rate that is manipulated to be significantly faster or slower than their walking rate. Comparison of distance estimates from before and after this recalibration experience typically shows that people who experience faster optic flow undershoot targets at posttest and people who experience slower optic flow overshoot targets at posttest. Here, we examined how experience with mismatched perception and action (i.e., faster or slower optic flow) in a virtual environment affects subsequent distance estimation in the same virtual environment and in a similar real environment. Of particular interest was whether perception-action coupling is more malleable in the virtual environment than in the real environment.

To control upright stance, the human nervous system must estimate the movements of multiple body segments based on multisensory information. To investigate how visual information contributes to such multisegmental estimation, participants were exposed to 3 types of visual-scene movement: translation in the anteroposterior direction, rotation about the ankle joint, and rotation about the hip joint. Trunk and leg responses were larger for rotational than for translational movements, but only at lower stimulus frequencies. Based on a feedback-control theoretical framework, these results indicated that visual inputs distinguish between translation and rotation of the head. Also, visual condition effects were similar for the leg and trunk segments, suggesting a control strategy with a single control signal that determines the activation of all muscles.

SUMMARYFlies, like all animals that depend on vision to navigate through the world, must integrate the optic flow created by self-motion with the images generated by prominent features in their environment. Although much is known about the responses of Drosophila melanogaster to rotating flow fields, their reactions to the more complex patterns of motion that occur as they translate through the world are not well understood. In the present study we explore the interactions between two visual reflexes in Drosophila: object fixation and expansion avoidance. As a fly flies forward, it encounters an expanding visual flow field. However, recent results have demonstrated that Drosophila strongly turn away from patterns of expansion. Given the strength of this reflex, it is difficult to explain how flies make forward progress through a visual landscape. This paradox is partially resolved by the finding reported here that when undergoing flight directed towards a conspicuous object, Drosophila will tolerate a level of expansion that would otherwise induce avoidance. This navigation strategy allows flies to fly straight when orienting towards prominent visual features.

The study is a commentary on the research of Cooper, Uller, Pettifer and Stole (Acta Paediatrica 2009). Cooper et al found that 6 - to 7-year-olds attentinal system appeared to be more supported by fewer changes and longer durations of views on a deading aloud teacher. Lange-Küttner suggests that future research might test (1) the left-right bias rather than up-down or widening of attention, as this is a crucial parameter in spatial cognition and ADHD disorder, (2) the contingency of view and sentence complexion of the filmed speaker.

Short paper - Section III. Original Research - Also published in Advanced Technologies in the Behavioral Social and Neurosciences (vol. 7): http://fr.scribd.com/doc/17030552); International audience; The control of gaze and balance strongly depend on the processing of visual cues. The aim of this study is to assess the effects of the dynamic 2D and 3D visual inputs on the oculomotor and balance reactive control. Thirteen subjects were immersed in a virtual environment using 10 different 2D/3D visual flow conditions. Analysis of eye movement and postural adjustments shows that 2D and 3D flows induce specific measurable behavioral responses.

Pilot spatial disorientation (SD) is a significant cause of incidents and fatal accidents in aviation. The pilot is susceptible to SD especially in low visibility when the visual system is deprived of information from outside the cockpit. This thesis presents the notion of visual flow displays as enhancement of symbology on flight displays primarily in low visibility for improved support of the pilot’s spatial orientation (SO) and control actions. In Studies I and II, synthetic visual flow of forward ego-motion was presented on displays and postural responses were used as measures of display effectiveness in determining SO. The visual flow significantly affected SO, and although the increased stimulation of the visual periphery from a width of 45° to about 105° increased the effects there was no further effect at a width of about 150° (Studies I and II). Studies I and II also showed that omitting 20°- or 30°-wide central fields of view from the visual flow either reduced or not reduced the effects. Further, although inconclusive, Study II may indicate that horizon symbology in central visual field may enhance the effects of peripheral visual flow. The appropriate integration of peripheral visual flow with the head-up display symbology of the Gripen aircraft was presented. Acceleration in a human centrifuge was used in Study III to investigate the effects of synthetic visual flow on the primarily vestibular-dependent somatogravic illusion of pitch-up. Two experiments revealed a reduced illusion with the visual flow. The results of Experiment 2 showed the visual flow scene not only reduced the illusion compared with a darkness condition but also compared with the visual scene without visual flow. Thus, similar to the main findings of Studies I and II, synthetic visual flow can significantly affect SO and supports the visually dependent SO system in an essential manner.

A low-cost solution for a visual flow field device is described. The apparatus generates progressive and regressive patterns of motion with variable angular speeds and intensities. Additionally, rotational stimuli can be applied. First results show the efficiency of the flow field in producing flight behavior and steering responses in visual interneurons of locusts.

The results suggest that after a sudden change in the visual input, postural adaptation is impaired in patients with instability and central nervous system disorders (CNSD).The aim of this study was the assessment of postural adaptation, as a transient phenomenon, when sudden changes in visual perception occur in normal subjects and in patients with instability due to different CNSD.Horizontal optokinetic stimulation (40 s and suddenly stopped) was performed in 16 patients with CNSD, and also in 22 normal subjects. Measurements were made of the body center of pressure area (COP) and the body sway velocity (SV) during 10 s before and after the stop and labeling the COP trajectory.Values of COP and SV (Wilcoxon signed rank test, p=0.979 and 0.496, respectively) in normal subjects did not show any significant change before and after the stop. In 15 of the 16 assessed patients with instability associated with CNSD an increase of the COP and SV values (Wilcoxon signed test, p=0.001 and 0.004, respectively) was observed in the 10 s after the visual stop. COP labeling showed 'roaming' of the COP spatial evolution approaching the limits of stability.