• stimulus
  • The responses to the two modified stimuli are strongly different from the response to the original stimulus, showing the importance of translation and saccades for the H1 response to natural optic flow. (jneurosci.org)
  • We found that the H1 response to natural optic flow is dominated by two stimulus characteristics that were not considered in previous studies of H1. (jneurosci.org)
  • The concept of optical flow was introduced by the American psychologist James J. Gibson in the 1940s to describe the visual stimulus provided to animals moving through the world. (wikipedia.org)
  • motion
  • When flying through narrow spaces, insects control their position by balancing the magnitude of apparent image motion (optic flow) experienced in each eye and their speed by holding this value about a desired set-point. (lu.se)
  • article{de4300f1-6416-4925-99a4-0c5db7d5cc85, abstract = {When flying through narrow spaces, insects control their position by balancing the magnitude of apparent image motion (optic flow) experienced in each eye and their speed by holding this value about a desired set-point. (lu.se)
  • Electroencephalogram (EEG) was used in preterm and full-term infants at 5 and 12 months of age to longitudinally study brain electrical activity as a function of perception of structured forward optic flow, structured reversed optic flow, and non-structured random visual motion. (bibsys.no)
  • In full-term infants, VEP results revealed a significant decrease in latencies for forward and reversed optic flow, but not for random visual motion with age. (bibsys.no)
  • At 12 months, full-term infants were also found to significantly differentiate between the three motion conditions, with shortest latencies for forward optic flow, and longest latencies for random visual motion. (bibsys.no)
  • When the TSEs of the three motion conditions were compared to the TSEs of a static non-flow control condition, full-term infants at 5 and 12 months showed significant differences in induced activity. (bibsys.no)
  • Early visual experience and the receptive-field organization of optic flow processing interneurons in the fly motion pathway", Visual neuroscience , vol. 18, 2001, pp. 1-8. (uni-bielefeld.de)
  • Using a luminance-based sensor that mimics the insect ocelli and a camera-based motion detection system, frequency-domain characterization of an ocellar sensor and optic flow (due to rotational motion) are analyzed. (final-year-projects.in)
  • There he worked mainly in the psychophysics of human visual perception, on phenomena surrounding higher-order motion aftereffects, visual search and attention in the real world, visual flow fields, and eye movements. (wikipedia.org)
  • Asymmetrical masking between radial and parallel motion flow in transparent displays. (wikipedia.org)
  • Motion camouflage Optic flow Gibson, J. J. (2014). (wikipedia.org)
  • One major source of visual information when determining self-motion is optic flow. (wikipedia.org)
  • Optical flow or optic flow is the pattern of apparent motion of objects, surfaces, and edges in a visual scene caused by the relative motion between an observer and a scene. (wikipedia.org)
  • The term optical flow is also used by roboticists, encompassing related techniques from image processing and control of navigation including motion detection, object segmentation, time-to-contact information, focus of expansion calculations, luminance, motion compensated encoding, and stereo disparity measurement. (wikipedia.org)
  • The optical flow methods try to calculate the motion between two image frames which are taken at times t and t + Δ t {\displaystyle t+\Delta t} at every voxel position. (wikipedia.org)
  • Motion estimation and video compression have developed as a major aspect of optical flow research. (wikipedia.org)
  • The application of optical flow includes the problem of inferring not only the motion of the observer and objects in the scene, but also the structure of objects and the environment. (wikipedia.org)
  • The principal form of motion camouflage, and the type generally meant by the term, involves an attacker's mimicking the optic flow of the background as seen by its target. (wikipedia.org)
  • First discovered in hoverflies in 1995, motion camouflage by minimising optic flow has been demonstrated in another insect order, dragonflies, as well as in two groups of vertebrates, falcons and echolocating bats. (wikipedia.org)
  • This is not the same as moving straight towards the target (classical pursuit): that results in visible sideways motion with a readily detectable difference in optic flow from the background. (wikipedia.org)
  • parameters
  • One way to assess the accuracy of the flow estimation is to synthesise the second image by warping the first with a known flow field, then seeing if we can recover the parameters of the field. (mathworks.com)
  • field
  • Bumblebees measure optic flow for position and speed control flexibly within the frontal visual field. (lu.se)
  • Previously, it has been shown that when bumblebees encounter sudden changes in the proximity to nearby surfaces - as indicated by a change in the magnitude of optic flow on each side of the visual field - they adjust their flight speed well before the change, suggesting that they measure optic flow for speed control at low visual angles in the frontal visual field. (lu.se)
  • We tested whether human observers maintain ideal patterns of information use across the visual field (VF) in determining direction of heading (DOH) from optic flow. (arvojournals.org)
  • While the ideal observer model explains some of the complex patterns human observers exhibit in weighing information across the visual field, it did not predict their bias to rely on the upper half of the visual field in determining direction of heading from optic flow. (arvojournals.org)
  • edges
  • We can see whether the flow that has been found maps the first image onto the second, by displaying edges. (mathworks.com)
  • Here, the green edges are the original first image, the blue edges are the second image, and the red edges are the first image after warping by the flow. (mathworks.com)
  • closer
  • It will, for example, fly down the middle of a tunnel, because if it flew closer to one side the optic flow would appear to be greater. (wikipedia.org)
  • results
  • Furthermore, these results provide the first piece of evidence on optic flow processing in the CN, which, in more general terms, indicates the possible role of this structure in dynamic visual information processing. (nih.gov)
  • mechanism
  • The authors propose a potential mechanism for cell death, whereby elevated intraocular pressure causes fluid to permeate axonal membranes, creating a passive intracellular fluid flow within the axons. (cpib.ac.uk)
  • A visual mechanism for extraction of heading information in complex flow fields. (wikipedia.org)
  • order
  • As a result, the first-order flow provides an approximation to the true flow, though it does not capture its details or exact form. (mathworks.com)
  • We do not expect exact overlap because the first-order flow can only be an approximate, smooth, model of the true flow. (mathworks.com)
  • SFM from 2nd order optic flow and perspective effects. (wikipedia.org)
  • cell
  • Fig 4C and 4D and Fig 6 show the responses of three HFNs to optic flow (one cell with decreased and two cells with increased activity). (nih.gov)
  • It is hypothesized that this intracellular flow locally depletes the adenosine triphosphate (ATP) concentration, disrupting axonal transport and leading to cell death. (cpib.ac.uk)
  • H1 is a lobula plate tangential cell (LPTC) located in the lobula plate of the optic lobe, the final destination of visual information originating from photoreceptors of the eye. (wikipedia.org)
  • eyes
  • When avoiding objects, the bee will tend to take the optimal path because it will 'balance' the rate of the optic flow between the eyes. (wikipedia.org)
  • fields
  • It would be possible to refine this experimentally, given an error measure, a set of images, and a set of flow fields. (mathworks.com)
  • maximum
  • the smoothing constant) needs to be set either using some prior knowledge of the likely maximum flow speed, or by experiment. (mathworks.com)
  • another
  • Panels C and D show the responses of another HFN to static as well as to optic flow stimulation. (nih.gov)
  • To find the optical flow another set of equations is needed, given by some additional constraint. (wikipedia.org)
  • Another laser beam (at either ~248 nm or ~308 nm) in the form of a sheet is also passed through the flow in the same plane as the grid. (wikipedia.org)
  • flight
  • Srinivasan has shown that many ostensibly complex flight behaviours can be attributed to the tendency of the bee to keep optic flow constant. (wikipedia.org)
  • image
  • The flow is estimated as for the real image pair. (mathworks.com)
  • Optical flow was used by robotics researchers in many areas such as: object detection and tracking, image dominant plane extraction, movement detection, robot navigation and visual odometry. (wikipedia.org)
  • often
  • HTV uses a laser (often an argon-fluoride excimer laser operating at ~193 nm) to dissociate the water in the flow into H + OH. (wikipedia.org)
  • form
  • Even the overall form of the real flow is a perspective rather than an affine transformation, and there is a lot of depth variation which adds complexity. (mathworks.com)
  • case
  • In one case of non-arteritic ischemic optic neuropathy, the flow was abnormally low in the affected superior hemisphere and normal in the unaffected hemisphere. (arvojournals.org)
  • movement
  • Six participants aged 18-22 fixated centrally while monocularly viewing flow patterns simulating straight-line movement in depth through a 3D cloud of dots. (arvojournals.org)