P J Bex

Summary

Affiliation: University College London
Country: UK

Publications

  1. ncbi request reprint Resolution of complex motion detectors in the central and peripheral visual field
    Peter J Bex
    Institute of Ophthalmology, University College London, London EC1V 9EL, UK
    J Opt Soc Am A Opt Image Sci Vis 23:1598-607. 2006
  2. ncbi request reprint Critical band masking in optic flow
    Peter J Bex
    Division of Visual Rehabilitation Research, The Institute of Ophthalmology, London, UK
    Network 16:261-84. 2005
  3. ncbi request reprint Spatial interference among moving targets
    Peter J Bex
    Institute of Ophthalmology, University College London, 11 43 Bath Street, London EC1V 9EL, UK
    Vision Res 45:1385-98. 2005
  4. ncbi request reprint The shape and size of crowding for moving targets
    Peter J Bex
    Institute of Ophthalmology, University College London, 11 43 Bath Street, London EC1V 9EL, UK
    Vision Res 43:2895-904. 2003
  5. ncbi request reprint Grouping local directional signals into moving contours
    Peter J Bex
    Institute of Ophthalmology, 11 43 Bath Street, EC1V 9EL, London, UK
    Vision Res 43:2141-53. 2003
  6. ncbi request reprint Motion detection and the coincidence of structure at high and low spatial frequencies
    Peter J Bex
    Institute of Ophthalmology, 11 43 Bath Street, EC1V 9EL, London, UK
    Vision Res 43:371-83. 2003
  7. ncbi request reprint Spatial frequency, phase, and the contrast of natural images
    Peter J Bex
    Institute of Ophthalmology, London, UK
    J Opt Soc Am A Opt Image Sci Vis 19:1096-106. 2002
  8. ncbi request reprint Snakes and ladders: the role of temporal modulation in visual contour integration
    P J Bex
    Institute of Ophthalmology, 11 43 Bath Street, London EC1V 9EL, UK
    Vision Res 41:3775-82. 2001
  9. ncbi request reprint Comparison of the spatial-frequency selectivity of local and global motion detectors
    Peter J Bex
    Institute of Ophthalmology, London, UK
    J Opt Soc Am A Opt Image Sci Vis 19:670-7. 2002
  10. ncbi request reprint Local and global visual grouping: tuning for spatial frequency and contrast
    S C Dakin
    Institute of Ophthalmology, University College London, London, United Kingdom
    J Vis 1:99-111. 2001

Detail Information

Publications34

  1. ncbi request reprint Resolution of complex motion detectors in the central and peripheral visual field
    Peter J Bex
    Institute of Ophthalmology, University College London, London EC1V 9EL, UK
    J Opt Soc Am A Opt Image Sci Vis 23:1598-607. 2006
    ..However, such pooling limits the precision with which multiple looming objects can be discriminated, especially in the peripheral visual field...
  2. ncbi request reprint Critical band masking in optic flow
    Peter J Bex
    Division of Visual Rehabilitation Research, The Institute of Ophthalmology, London, UK
    Network 16:261-84. 2005
    ..Our results suggest that visual processing normalises responses to supra-threshold structure at different spatial and temporal frequencies within natural stimuli and so equates their effective visibility...
  3. ncbi request reprint Spatial interference among moving targets
    Peter J Bex
    Institute of Ophthalmology, University College London, 11 43 Bath Street, London EC1V 9EL, UK
    Vision Res 45:1385-98. 2005
    ..The underlying connectivity of this integration favours low spatial frequency structure but is broadly tuned for speed...
  4. ncbi request reprint The shape and size of crowding for moving targets
    Peter J Bex
    Institute of Ophthalmology, University College London, 11 43 Bath Street, London EC1V 9EL, UK
    Vision Res 43:2895-904. 2003
    ..These results reveal asymmetrical space-time dependent regions of visual integration that are radially organised about central vision...
  5. ncbi request reprint Grouping local directional signals into moving contours
    Peter J Bex
    Institute of Ophthalmology, 11 43 Bath Street, EC1V 9EL, London, UK
    Vision Res 43:2141-53. 2003
    ..The visibility of these moving contours identifies narrow-band grouping processes that are sensitive to the shape defined by the directions of the elements forming the contour...
  6. ncbi request reprint Motion detection and the coincidence of structure at high and low spatial frequencies
    Peter J Bex
    Institute of Ophthalmology, 11 43 Bath Street, EC1V 9EL, London, UK
    Vision Res 43:371-83. 2003
    ..Both are required to account for the two results, and they appear to operate under very similar conditions...
  7. ncbi request reprint Spatial frequency, phase, and the contrast of natural images
    Peter J Bex
    Institute of Ophthalmology, London, UK
    J Opt Soc Am A Opt Image Sci Vis 19:1096-106. 2002
    ..We argue that these observations are consistent with changes in the activity within spatial-frequency channels caused by the higher-order phase structure of natural images that is responsible for the presence of edges and specularities...
  8. ncbi request reprint Snakes and ladders: the role of temporal modulation in visual contour integration
    P J Bex
    Institute of Ophthalmology, 11 43 Bath Street, London EC1V 9EL, UK
    Vision Res 41:3775-82. 2001
    ..These results lend further support to the notion that the contour integration system receives separate transient and sustained input...
  9. ncbi request reprint Comparison of the spatial-frequency selectivity of local and global motion detectors
    Peter J Bex
    Institute of Ophthalmology, London, UK
    J Opt Soc Am A Opt Image Sci Vis 19:670-7. 2002
    ..e., they integrate across a broad range of spatial frequencies), with a preference for low spatial frequencies...
  10. ncbi request reprint Local and global visual grouping: tuning for spatial frequency and contrast
    S C Dakin
    Institute of Ophthalmology, University College London, London, United Kingdom
    J Vis 1:99-111. 2001
    ..We conclude that local grouping is consistent with the use of simple-oriented filtering mechanisms. Global grouping seems to depend more on the visibility of elements that can be affected by both spatial frequency and contrast...
  11. pmc Dissociable effects of attention and crowding on orientation averaging
    Steven C Dakin
    UCL Institute of Ophthalmology, University College London, London, UK
    J Vis 9:28.1-16. 2009
    ....
  12. pmc Illusory stimuli can be used to identify retinal blind spots
    Michael D Crossland
    University College London Institute of Ophthalmology, London, United Kingdom
    PLoS ONE 2:e1060. 2007
    ....
  13. ncbi request reprint Contrast adaptation implies two spatiotemporal channels but three adapting processes
    Keith Langley
    Department of Psychology, University College London, UK
    J Exp Psychol Hum Percept Perform 33:1283-96. 2007
    ....
  14. pmc The twinkle aftereffect is pre-cortical and is independent of filling-in
    Michael D Crossland
    UCL Institute of Ophthalmology, London, UK
    J Vis 8:13.1-10. 2008
    ..These results indicate that the TwAE involves additive noise that is pre-cortical in origin and that it is distinct from filling-in...
  15. pmc Spatial alignment over retinal scotomas
    Michael D Crossland
    University College London Institute of Ophthalmology, London, United Kingdom
    Invest Ophthalmol Vis Sci 50:1464-9. 2009
    ..Similarities between the completion of pathologic and physiological scotomas would be consistent with large-scale reorganization of the visual system in eye disease..
  16. pmc Crowding changes appearance
    John A Greenwood
    UCL Institute of Ophthalmology, University College London, 11 43 Bath Street, London EC1V9EL, UK
    Curr Biol 20:496-501. 2010
    ..These results confirm predictions from change-based models of crowding, such as averaging, and establish crowding as a regularization process that simplifies the peripheral field by promoting consistent appearance among adjacent objects...
  17. pmc Positional averaging explains crowding with letter-like stimuli
    John A Greenwood
    UCL Institute of Ophthalmology, University College London, 11 43 Bath Street, London EC1V 9EL, United Kingdom
    Proc Natl Acad Sci U S A 106:13130-5. 2009
    ..Together, our results suggest that crowding is a preattentive process that uses averaging to regularize the noisy representation of position in the periphery...
  18. pmc The aperture problem in contoured stimuli
    David Kane
    UCL Institute of Ophthalmology, University College London, London EC1V 9EL, United Kingdom
    J Vis 9:13.1-17. 2009
    ..We report that global motion integration is (a) largely insensitive to the second-order statistics of such stimuli and (b) is rigidly broadband even in the presence of a disrupted low SF component...
  19. doi request reprint Probabilistic, positional averaging predicts object-level crowding effects with letter-like stimuli
    Steven C Dakin
    Institute of Ophthalmology, University College London, London, UK
    J Vis 10:14. 2010
    ..Thus, we demonstrate a set of seemingly "high-level" object-centered crowding effects that can arise from "low-level" interactions between the features of letter-like elements...
  20. pmc Dynamic properties of orientation discrimination assessed by using classification images
    Isabelle Mareschal
    Institute of Ophthalmology, University College London, Bath Street, London EC1V 9EL, United Kingdom
    Proc Natl Acad Sci U S A 103:5131-6. 2006
    ....
  21. ncbi request reprint Role of synchrony in contour binding: some transient doubts sustained
    Steven C Dakin
    Institute of Ophthalmology, University College London, UK
    J Opt Soc Am A Opt Image Sci Vis 19:678-86. 2002
    ....
  22. ncbi request reprint Perceived blur in amblyopia
    Anita J Simmers
    Institute of Ophthalmology, University College London, London, United Kingdom
    Invest Ophthalmol Vis Sci 44:1395-400. 2003
    ..In the current study, the representation of blur in amblyopia with blur-discrimination and blur-matching tasks was explored in a series of experiments...
  23. pmc Natural image statistics mediate brightness 'filling in'
    Steven C Dakin
    Department of Visual Science, Institute of Ophthalmology, University College London, 11 43 Bath Street, London EC1V 9EL, UK
    Proc Biol Sci 270:2341-8. 2003
    ..As predicted by the model, the filling-in process is contingent on the presence of appropriate low SF structure...
  24. ncbi request reprint The representation of global spatial structure in amblyopia
    Anita J Simmers
    The Institute of Ophthalmology, University College London, EC1V 9EL London, UK
    Vision Res 44:523-33. 2004
    ..It is this increased spatial uncertainty that underlies the spatial deficit in amblyopia...
  25. ncbi request reprint Local and global limitations on direction integration assessed using equivalent noise analysis
    Steven C Dakin
    Department of Visual Science, Institute of Ophthalmology, University College London, 11 43 Bath Street, London EC1V 9EL, UK
    Vision Res 45:3027-49. 2005
    ..A population vector-averaging scheme (essentially a special case of ML estimation) produces similar predictions but out-performs subjects at high levels of directional variability and fails to predict motion coherence thresholds...
  26. ncbi request reprint An oblique effect for local motion: psychophysics and natural movie statistics
    Steven C Dakin
    Institute of Ophthalmology, University College London, Bath Street, London, United Kingdom
    J Vis 5:878-87. 2005
    ..If motion detectors are optimized to deal with our visual world then such anisotropies likely explain the local nature of the OEM...
  27. ncbi request reprint Summation of concentric orientation structure: seeing the Glass or the window?
    S C Dakin
    Institute of Ophthalmology, University College London, 11 43 Bath Street, London EC1V 9EL, UK
    Vision Res 42:2013-20. 2002
    ..We conclude that this paradigm presently offers no concrete psychophysical evidence for specialised concentric orientation detectors...
  28. ncbi request reprint Deficit of visual contour integration in dyslexia
    A J Simmers
    Department of Visual Rehabilitation, Institute of Ophthalmology, University College London, United Kingdom
    Invest Ophthalmol Vis Sci 42:2737-42. 2001
    ..In the present study a contour integration task was used to investigate such perceptual organization in dyslexia...
  29. ncbi request reprint Contextual modulation of the motion aftereffect
    Helle K Falkenberg
    Institute of Ophthalmology, University College London, London, UK
    J Exp Psychol Hum Percept Perform 33:257-70. 2007
    ..Collectively, these results suggest that motion processing, similar to texture processing, is organized for the purpose of highlighting regions of directional discontinuity in retinal images...
  30. ncbi request reprint The perception of suprathreshold contrast and fast adaptive filtering
    Peter J Bex
    Schepens Eye Research Institute, Harvard Medical School, Boston, MA 02114, USA
    J Vis 7:1.1-23. 2007
    ....
  31. ncbi request reprint Sources of motion-sensitivity loss in glaucoma
    Helle K Falkenberg
    Department of Optometry and Vision Science, Buskerud University College, Kongsberg, Norway
    Invest Ophthalmol Vis Sci 48:2913-21. 2007
    ..In this study, a signal-to-noise motion-sensitivity task was used to investigate the sources of motion-sensitivity loss in patients with POAG...
  32. ncbi request reprint Contrast conservation in human vision
    Jozsef Fiser
    Center for Visual Science, University of Rochester, Rochester, NY 14627 0268, USA
    Vision Res 43:2637-48. 2003
    ....
  33. ncbi request reprint Acuity, crowding, reading and fixation stability
    Helle K Falkenberg
    Department of Optometry and Visual Science, Buskerud University College, Frogsvei 41, 3601 Kongsberg, Norway
    Vision Res 47:126-35. 2007
    ..The results suggest that unstable fixation may contribute to reading difficulties in people with low vision and therefore that rehabilitation may benefit from fixation training...
  34. ncbi request reprint Contrast gain control in natural scenes
    Peter J Bex
    Schepens Eye Research Institute, Harvard Medical School, Boston, MA 02114, USA
    J Vis 7:12.1-12. 2007
    ..This process tends to normalize the response of the visual system across natural scenes, which contain uneven contrast distributions...