Research Topics
| Steven DakinSummaryAffiliation: University College London Country: UK Publications
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Detail Information
Publications
The development of an automated sentence generator for the assessment of reading speedMichael D Crossland
UCL Institute of Ophthalmology, London, UK
Behav Brain Funct 4:14. 2008..The automated sentence generator would be useful for measuring reading speed with button-press response (such as within MRI scanners) and for studies requiring many repeated measures of reading speed...
Contour integration and scale combination processes in visual edge detectionS C Dakin
McGill Vision Research, Department of Ophthalmology, Montreal, Quebec, Canada
Spat Vis 12:309-27. 1999..Moreover, unlike contours composed of Gabors, the bandwidth of local elements is important for edge integration; the coding of element bandwidth seems to be dependent on the phase alignment of features across spatial frequency...
Biological "bar codes" in human facesSteven C Dakin
UCL Institute of Ophthalmology, University College London, Bath Street, London EC1V 9EL, UK
J Vis 9:2.1-10. 2009....- Dissociable effects of attention and crowding on orientation averagingSteven C Dakin
UCL Institute of Ophthalmology, University College London, London, UK
J Vis 9:28.1-16. 2009.... - Psychophysical evidence for a non-linear representation of facial identitySteven C Dakin
UCL Institute of Ophthalmology, University College London, EC1V 9EL London, UK
Vision Res 49:2285-96. 2009.... - 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... - Context influences contour integrationSteven C Dakin
UCL Institute of Ophthalmology, University College London, London, UK
J Vis 9:13.1-13. 2009..Specifically we show that our results are consistent with contour integration relying on an opponent-orientation energy response from a bank of first-stage oriented filters... - Local and global limitations on direction integration assessed using equivalent noise analysisSteven 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... - Vagaries of visual perception in autismSteven Dakin
Institute of Ophthalmology, University College London, Bath Street, London EC1V 9EL, United Kingdom
Neuron 48:497-507. 2005..Such an explanation may also provide a link between perceptual abnormalities and specific deficits in social cognition associated with autism... - Vision: thinking globally, acting locallySteven C Dakin
UCL Institute of Ophthalmology, University College London, Bath Street, London EC1V 9EL, UK
Curr Biol 19:R851-4. 2009..The global structure of images profoundly influences how we see their local detail, consistent with activity in primary visual cortex being disambiguated via feedback from later visual areas... - Probabilistic, positional averaging predicts object-level crowding effects with letter-like stimuliSteven 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... - The interaction of first- and second-order cues to orientationS C Dakin
McGill Vision Research, Department of Ophthalmology, Montreal, Quebec, Canada
Vision Res 39:2867-84. 1999..We propose that illusory tilting of the envelope is due to selective connectivity between first- and second-stage filters whose purpose is to dissociate the type of image structure producing each class of cue... - The role of relative motion computation in 'direction repulsion'S C Dakin
Department of Visual Science, Institute of Ophthalmology, 11 43 Bath Street, London, UK
Vision Res 40:833-41. 2000..The effects of speed cannot be reconciled with the scheme as it stands, but this could be due to the model's failure to consider the effect of temporal frequency on the effective contrast of the sets... - Sensitivity to contrast modulation depends on carrier spatial frequency and orientationS C Dakin
McGill Vision Research, Department of Ophthalmology, Montreal, Que, Canada
Vision Res 40:311-29. 2000..A final experiment measured envelope detection in the presence of noise masks. Results indicate that orientationally and spatially-band pass filtering precedes the detection of second-order structure... - Information limit on the spatial integration of local orientation signalsS C Dakin
Institute of Ophthalmology, University College London, UK
J Opt Soc Am A Opt Image Sci Vis 18:1016-26. 2001..Orientation pooling is entirely flexible with respect to the position of input features... - Local and global visual grouping: tuning for spatial frequency and contrastS 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... - Role of synchrony in contour binding: some transient doubts sustainedSteven C Dakin
Institute of Ophthalmology, University College London, UK
J Opt Soc Am A Opt Image Sci Vis 19:678-86. 2002.... - 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... - Anisotropies in judging the direction of moving natural scenesSteven C Dakin
Institute of Ophthalmology, University College London, London, UK
J Vis 10:5. 2010..g., around cardinal directions). This bias change can improve direction discrimination but is not due to a reduction in variability... - An oblique effect for local motion: psychophysics and natural movie statisticsSteven 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... - A common visual metric for approximate number and densitySteven C Dakin
Institute of Ophthalmology, University College London, London EC1V 9EL, United Kingdom
Proc Natl Acad Sci U S A 108:19552-7. 2011..This model is a simple, biologically plausible common metric for perceptual number and density... - Deficits in local and global motion perception arising from abnormal eye movementsMagella M Neveu
Department of Visual Neuroscience, Institute of Ophthalmology, UCL, London, UK
J Vis 9:9.1-15. 2009.... - Visually-based temporal distortion in dyslexiaAlan Johnston
Department of Psychology, University College London, Gower Street, London WC1E 6BT, UK
Vision Res 48:1852-8. 2008.... - Critical band masking in optic flowPeter 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... - Comparison of the spatial-frequency selectivity of local and global motion detectorsPeter 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... - The aperture problem in contoured stimuliDavid 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... - Dynamic properties of orientation discrimination assessed by using classification imagesIsabelle 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.... - Monocular signals in human lateral geniculate nucleus reflect the Craik-Cornsweet-O'Brien effectElaine J Anderson
Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, London, UK
J Vis 9:14.1-18. 2009..Our observations suggest that the CCOB effect arises from signals in populations of monocular neurons very early in the human geniculostriate visual pathway... - Crowding changes appearanceJohn 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... - Theories of developmental dyslexia: insights from a multiple case study of dyslexic adultsFranck Ramus
Institute of Cognitive Neuroscience, University College London, London, UK
Brain 126:841-65. 2003..Overall, the present data support the phonological theory of dyslexia, while acknowledging the presence of additional sensory and motor disorders in certain individuals... - Motion detection and the coincidence of structure at high and low spatial frequenciesPeter 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... - Grouping local directional signals into moving contoursPeter 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... - The shape and size of crowding for moving targetsPeter 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... - Integration of orientation information in amblyopiaBehzad Mansouri
McGill Vision Research Unit, 687 Pine Avenue West, Rm H4 14, Montreal, Quebec, Canada H3A 1A1
Vision Res 44:2955-69. 2004..Although internal noise was slightly elevated, there was no indication that fewer samples were used to achieve optimal performance. This finding suggests normal integration of local orientation signals in amblyopia... 
Illusory stimuli can be used to identify retinal blind spotsMichael D Crossland
University College London Institute of Ophthalmology, London, United Kingdom
PLoS ONE 2:e1060. 2007....- Positional averaging explains crowding with letter-like stimuliJohn 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... - Spatial interference among moving targetsPeter 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... - Flank facilitation and contour integration: different sitesPi Chun Huang
McGill Vision Research, Department of Ophthalmology, McGill University, Montreal, Que, Canada
Vision Res 46:3699-706. 2006..We conclude that the sites, and therefore the mechanisms, underlying these two seemingly related psychophysical phenomena are different... - Integration of local motion is normal in amblyopiaRobert F Hess
McGill Vision Research Unit, Montreal, Quebec, Canada
J Opt Soc Am A Opt Image Sci Vis 23:986-92. 2006..45, 449 (2005)]. We suggest that these discrepancies for form and motion processing in amblyopia point to a selective problem in separating signal from noise in the typical global coherence task... - Sparsely distributed contours dominate extra-striate responses to complex scenesSerge O Dumoulin
McGill Vision Research Unit, Department of Ophthalmology, McGill University, Montreal, Canada
Neuroimage 42:890-901. 2008..Later visual cortex (and to a modest degree V1) incorporates a facilitation of contour-based structure and suppressive interactions that effectively amplify sparse-contour information within natural images... - Integration, segregation, and binocular combinationBehzad Mansouri
McGill Vision Research, H4 14 Montreal, H3A 1A1 Quebec, Canada
J Opt Soc Am A Opt Image Sci Vis 22:38-48. 2005.... - Integration of first- and second-order orientationHarriet A Allen
McGill Vision Research Unit, 687 Pine Avenue West, Room H4 14, Montreal, H3A 1A1, Quebec, Canada
J Opt Soc Am A Opt Image Sci Vis 20:974-86. 2003..The visual system appears to have separate integrators for combining local orientation across space for luminance- and contrast-defined features... - Visual perception and its impairment in schizophreniaPamela D Butler
Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA
Biol Psychiatry 64:40-7. 2008.... - Contrast gain control in natural scenesPeter 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...