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  1. Centre for Applied Vision Research
  2. Visual Neuroscience and Psychophysics
School of Health Sciences

Visual Neuroscience and Psychophysics

The disciplines within this group seek to explain mechanisms of vision from the retina to the cortex using a range of techniques based on the measurement of involuntary responses, brain imaging, behavioural studies and visual psychophysics. 

The Visual Neuroscience labs study how cells along the visual pathway, from the photoreceptors of the retina to the neurons of the visual centres of the brain, process visual information. The work focuses on understanding the properties of visual mechanisms in a variety of species, using anatomical, biochemical, physiological and behaviourally based experimental techniques.

The majority of group members focus on the use of visual psychophysics to study the properties of both low and high level visual mechanisms. Emphasis is placed on studying subjects with damaged visual pathways and / or retinal and systemic diseases that affect vision. As a result, new tests that are specific for detecting early degradation of spatial vision, retinal inhibitory interactions, loss of chromatic sensitivity, binocular summation and motion perception have been developed and found important clinical applications. Improved understanding of the interaction of photoreceptor signals and the corresponding vision changes in the mesopic range led to new developments in lighting with direct application to residential streets. The group is also at the forefront internationally in developing standards for spatial and colour vision within visually-demanding occupations with new pass / fail limits for pilots, seafarers, fire-fighters and London Transport train drivers.


  • Dr William Blows
  • Dr Keith May
  • Dr Marisa Rodriguez-Carmona
  • Professor Christopher Tyler

PhD Students

  • Ruba Allisa
  • Julia Foerster
  • Joseph Hickey
  • Arjan Keuken
  • Roopa Vemala


2010, The visual pigments of the African clawed toad, Xenopus laevi. Awarded to R.H. Douglas Nuffield Foundation. £1,140.

2010, Aspects of the visual systems of mesopelagic deep-sea fish. Awarded to R.H. Douglas. Royal Society. £2.271

2011-2014, Effects of altitude hypoxia on visual performance. Awarded to JL Barbur Qinetiq Ltd £38,400

2014, Visiting Fellowship. Awarded to JL Barbur JSPS (Japan) £7,000

2008-2010, Pupil Control Mechanisms and Clinical Applications Awarded to JL Barbur Sasakawa Foundation £15,000

2011-2014, Mapping and remapping of visual space. Awarded to M. Morgan (PI) JA Solomon, S. Grant. Wellcome Trust. £314,000

2011-2014, Efficiency of Visual Statistics. Awarded to JA Solomon, M. Morgan, C Chubb. EPSRC. £541,000

Start Date to be confirmed, New methodologies to explain and improve the expert anticipatory advantage in sports decision making. Awarded to K. Yarrow with J. Solomon BBSRC £477,294

2012-2014, Visual Recognition's Advantage over Reproduction. Awarded to J. Solomon. Royal Society, £9,200

2011-2014, Human Oculomotor Functions & Their Deficits in Traumatic Brain Injury. Awarded to C.Tyler Agency CDMRP $1,257,343

2006-2011, Core Grant for Vision Research. Awarded to C.Tyler NIH/NEI $3,487,518

2008-2010, Short-, Medium- and Long-Term Neural Dynamics of Conceptual Learning. Awarded to C.Tyler NSF/SLC $298,000

2008-2010, Learning in the Sighted and the Blind through Different Sensory Modalities: Structure and Dynamics of Cortical Reorganization Awarded to C.Tyler NSF/SLC $300,000

2008-2009, NSF Workshop on Art, Creativity and Learning. Awarded to C.Tyler NSF/SLC $17,000

2006-2008, High Resolution fMRI Mapping of the Human Foveal Projection Awarded to C.Tyler Pacific Vision Foundation $26,000



Chen, C.C., Chen, C.M., Tyler, C.W. (2013) Depth structure from asymmetric shading supports face discrimination. PLoS One 8(2):e55865. doi: 10.1371/journal.pone.0055865.

Dillenburger B, Raphael S and Morgan M. (2013) Computation of relative numerosity of circular dot textures Journal of Vision 13 (2) art no. 17

Gorea, A., Tyler, C.W. (2013). Dips and bumps: on Bloch's law and the Broca-Sulzer phenomenon. PNAS. 9;110(15):E1330. doi: 10.1073/pnas.1221807110

Kontsevich, L.L., Tyler, C.W. (2013). A simpler structure for local spatial channels revealed by sustained perifoveal stimuli. Journal of Vision, 13 (1):22 doi: 10.1167/13.1.22

Lawrance-Owen A.J, Bargary G, Bosten J.M, Goodbourn P.T, Hogg R.E, Mollon J.D. (2013). Genetic association suggests that SMOC1 mediates between prenatal sex hormones and digit ratio. Human Genetics, 132(4):415-21

Li, X., Huang, A.E., Altschuler, E.L., Tyler, C.W. (2013). Depth spreading through empty space induced by sparse disparity cues (2013) Journal of Vision, 13 (10) doi:pii: 7. 10.1167/13.10.7

May, K.A. & Zhaoping, L. (2013). The potential roles of saturating and supersaturating contrast-response functions in conjunction detection: Reply to Peirce. Journal of Vision, 13(4):22, 1-4

Morgan M. (2013) Sustained attention is not necessary for velocity adaptation. Journal of Vision 13 (8)S

Ouhnana, M., Bell, J., Solomon, J. A. & Kingdom, F. A. A. (2013) After-effect of perceived regularity. Journal of Vision, 13(8):18, 1-13. doi: 10.1167/13.8.18

Perganta, G., Barnard,A., Katti, C., Vachtsevanos, A., Douglas, R.H., Maclaren, R., Votruba, M., Sekaran, S. (2013). Non-image-forming light driven functions are preserved in visually impaired Opa1 mutant mice. PLoS One 8(2), e56350

Samonds, J.M., Potetz, B.R., Tyler, CW., Lee ,T.S. (2013). Recurrent connectivity can account for the dynamics of disparity processing in V1. Journal of Neuroscience. 13;33(7):2934-46. doi: 10.1523/JNEUROSCI.2952-12.2013

Solomon, J. A., & Mareschal, I. (2013) The incompatibility of feature contrast and feature acuity. In C. Chubb, B. Dosher, Z.-L. Lu & R. Shiffrin (Eds.) Human Information Processing: Vision, Memory, Attention. Washington DC: American Psychological Association, 29-38


Goodbourn P.T., Bosten J.M., Hogg R.E., Bargary G., Lawrance-Owen A.J., Mollon J.D. 2012 Do different 'magnocellular tasks' probe the same neural substrate? Proceedings of the Royal Society B, 279(1745):4263-71

Huang, P.-C., Chen, C.-C., Tyler, C.W. (2012). Collinear facilitation over space and depth. Journal of Vision, 12 (2). doi:pii: 20. 10.1167/12.2.20

Huang, P.-C., Maehara,G., May, K.A. & Hess, R.F. (2012). Pattern masking: The importance of remote spatial frequencies and their phase alignment. Journal of Vision, 12(2):14, 1-13

Konstantakopoulou E, RodriguezCarmona M, Barbur JL, (2012) "Processing of color signals in female carriers of colour deficiency", Journal of Vision, 12 (2):11, 111

May, K.A., Zhaoping, L. & Hibbard, P.B. (2012). Perceived direction of motion determined by adaptation to static binocular images. Current Biology, 22, 28-32

McIlhagga, W.H. & May, K.A. (2012). Optimal edge filters explain human blur detection. Journal of Vision, 12(10):9, 1-13

Morgan M, Dillenburger B, Raphael S, Solomon JA. (2012) Observers can voluntarily shift their psychometric functions without losing sensitivity. Attention, Perception, & Psychophysics 74 (1), 185-193

Morgan MJ, Mareschal I, Chubb C, Solomon JA. (2012) Perceived pattern regularity computed as a summary statistic: implications for camouflage. Proceedings of the Royal Society B: Biological Sciences 279 (1739), 2754-2760 4

Morgan MJ. (2012) Motion adaptation does not depend on attention to the adaptor. Vision Research 55, 47-51 3

Schira, M.M., Tyler, C.W., Rosa, M.G.P. (2012). Brain mapping: The (un)folding of striate cortex. Current Biology, 22 (24), pp. 1051-1053. doi: 10.1016/j.cub.2012.11.003

Solomon, J. A., Cavanagh, P. & Gorea, A. (2012) Recognition criteria vary with fluctuating uncertainty. Journal of Vision, 12(8):2, 1-13. doi: 10.1167/12.8.2

Tyler, C.W., Elsaid, A.M., Likova, L.T., Gill, N., Nicholas, S.C. (2012). Analysis of human vergence dynamics. Journal of Vision, 12 (11) pii: 21. doi: 10.1167/12.11.21

Tyler, C.W., Likova, L.T. (2012). The role of the visual arts in the enhancing the learning process. Frontiers in Human Neuroscience, 6:8. doi: 10.3389/fnhum.2012.00008


Bridge H, Jindahra P, Barbur JL, and Plant G. (2011) "Imaging reveals optic tract degeneration in hemianopia," Invest Ophthalmol. Vis. Sci. 52, 382388 (2011).

Dakin S, Tibber M, Greenwood J, Morgan M. (2011) The common perceptual metric for human discrimination of number and density. Journal of Vision 11 (11), 1203-1203

Dakin SC, Tibber MS, Greenwood JA, Morgan MJ. (2011) A common visual metric for approximate number and density. Proceedings of the National Academy of Sciences 108 (49), 19552-19557

Hogg, C., Neveu, M., Stokkan, K-A, Folkow, L., Cottril, P., Douglas, RH, Hunt DM & Jeffery, G. (2011) Arctic reindeer extend their visual range into the ultraviolet. Journal of Experimental Biology 214(12), 2014-2019

May, K.A. & Zhaoping, L. (2011). Exploring the roles of saturating and supersaturating contrast-response functions in conjunction detection and contrast coding. Journal of Vision, 11(9):11, 1-15.

Morgan M, Dakin S. (2011) Density discriminations are less precise than size discriminations, but are not more noisy. Journal of Vision 11 (11), 1206-1206

Morgan M, Melmoth D. (2011) Eye movements show the Poggendorff illusion. Perception 40, 44-44

Morgan MJ, Chubb C, Solomon JA. (2011) Evidence for a subtractive component in motion adaptation. Vision Research 51 (21), 2312-2316

Morgan MJ. (2011) Features and the 'primal sketch'. Vision Research 51 (7), 738-753

Morgan MJ. (2011) Wohlgemuth was right: Distracting attention from the adapting stimulus does not decrease the motion after-effect. Vision Research 51 (20), 2169-2175

Ouhnana M, Bell J, Morgan MJ, Solomon JA. (2011) After-effect of perceived regularity. Journal of Vision 11 (11), 1084-1084

Raphael S, Dillenburger B, Morgan M. (2011) Numerosity Estimation Is Not Derived Only from Density and Size Judgments. Journal of Vision 11 (15), 59-59

Rauscher FG, Plant GT, JamesGalton M, and Barbur JL. (2011), "Evidence for Non Opponent Coding of Colour Information in Human Visual Cortex: Selective Loss of "Green" Sensitivity in a Subject with Damaged Ventral OccipitoTemporal Cortex," Neuroophthalmology 35, 16 (2011)

Solomon J, Morgan M, Chubb C. (2011) Efficiencies for the statistics of size. Journal of Vision 11 (11), 1041-1041

Solomon JA, Morgan M, Chubb C. (2011) Efficiencies for the statistics of size discrimination. Journal of Vision 11

Solomon, J. A. (2011, February 1). Commemorating Elemente der Psychophysik. In J. A. Solomon (Ed.), Fechner's Legacy in Psychology (pp. 216 pages). Brill Academic Pub

Solomon, J. A. (Ed.) (2011) Fechner's legacy in Psychology: 150 years of Elementary Psychophysics. Leiden: Brill Academic Publisher

Tyler, C.W. (2011). Paradoxical perception of surfaces in the Shepard tabletop illusion. i-Perception, 2 (2), pp. 137-141

Tyler, C.W., Chen, C.C. (2011). Chinese perspective as a rational system: relationship to Panofsky's symbolic form. Chinese Journal of Psychology, 53(4), 7-27.

Tyler, C.W., Likova, L.T. (2011). Estimating neural signal dynamics in the human brain. Frontiers in Systems Neuroscience, 5:33. doi: 10.3389/fnsys.2011.00033

Yammouni, R., Bozanno, A. & Douglas, R.H. (2011) A latitudinal cline in the efficacy of endogenous signals: evidence derived from retinal cone contraction in fish. Journal of Experimental Biology 214 (3), 501-508

Zhaoping, L., Geisler, W.S. & May, K.A. (2011). Human wavelength discrimination of monochromatic light explained by optimal wavelength decoding of light of unknown intensity. PLoS ONE, 6(5) e19248.


Chen, C.C., Tyler, C.W. (2010). Symmetry: Modeling the effects of masking noise, axial cueing and salience. PLoS ONE, 5 (4): e9840. doi: 10.1371/journal.pone.0009840

Constable, P. A., Solomon, J. A., Gaigg, S. B., & Bowler, D. M. (2010). Crowding and visual search in high functioning adults with autism spectrum disorder. Clinical Optometry, 2, 93-103.

Dayan, P., & Solomon, J. A. (2010, October). Selective Bayes Attentional load and crowding. Vision Research, 50(22), 2248-2260. doi:10.1016/j.visres.2010.04.014

Huang, A.E., Hon, A.J. Tyler, C.W., Altschuler, E.L. (2010.) Metameric intransitivity. Attention Perception and Psychophysics 72(4):891-3. doi: 10.3758/APP.72.4.891

M Morgan, I Mareschal, J Solomon (2010) Sampling Efficiencies for Spatial Regularity. Journal of Vision 10 (7), 1362-1362

Mareschal I, Morgan MJ, Solomon JA. (2010) Attentional modulation of crowding. Vision research 50 (8), 805-809

Mareschal I, Morgan MJ, Solomon JA. (2010) Cortical distance determines whether flankers cause crowding or the tilt illusion. Journal of Vision 10 (8)

Rodriguez-Carmona, M., O'Neill-Biba, M., and Barbur, J. L. (2010) Patterns of colour vision loss in patients with retinal and optic nerve disease. Neuro-ophthalmology, 34(3) June 2010: 139. ISSN: 0165-8107

Schira, M.M., Tyler, C.W., Spehar, B., Breakspear, M. (2010). Modeling magnification and anisotropy in the primate foveal confluence. PLoS Computational Biology, 6 (1) ):e1000651. doi: 10.1371/journal.pcbi.1000651

Solomon J, Morgan MJ, Chubb C. (2010) Efficiencies for estimating mean orientation, mean size, orientation variance and size variance. Journal of Vision 10 (7), 24-24

Solomon, J. A. (2010). Visual discrimination of orientation statistics in crowded and uncrowded arrays. Journal of Vision, 10(14), 1-16

Tibber M, Saygin AP, Grant S, Melmoth D, Rees G, Morgan M. (2010) The neural correlates of visuospatial perceptual and oculomotor extrapolation. PloS one 5 (3), e9664

Tomassini A, Morgan MJ, Solomon JA. (2010) Orientation uncertainty reduces perceived obliquity. Vision Research 50 (5), 541-547

Tyler, C.W., Likova, L.T. (2010). An algebra for the analysis of object encoding. NeuroImage, 50 (3), pp. 1243-1250



Bargary, G., Barnett, K. J., Mitchell, K. J. & Newell, F. N. (2009). Coloured-speech synaesthesia is triggered by multisensory, not unisensory, perception. Psychological Science, 20(5), 529-33.

Longbottom, R., Fruttiger, M., Douglas, R.H., Martinez-Barbera, J.P., Greenwood, J., & Moss, S.E. (2009) Genetic ablation of retinal pigment epithelial cells reveals the adaptive response of the epithelium and impact on photoreceptors. PNAS 106(44), 18728-18733

Mareschal I, Solomon J, Morgan M. (2009) Endogenous attention can reduce the tilt illusion, but not crowding Journal of Vision 9 (8), 126-126

May, K.A. & Zhaoping, L. (2009). Effects of surrounding frame on visual search for vertical or tilted bars. Journal of Vision, 9(13):20, 1-19

Melmoth DR, Finlay AL, Morgan MJ, Grant S. (2009) Grasping deficits and adaptations in adults with stereo vision losses Investigative ophthalmology & visual science 50 (8), 3711-3720

Melmoth DR, Tibber MS, Grant S, Morgan MJ. (2009) The Poggendorff illusion affects manual pointing as well as perceptual judgements Neuropsychologia 47 (14), 3217-3224

Nam JH, Solomon JA, Morgan MJ, Wright CE, C Chubb (2009) Coherent plaids are preattentively more than the sum of their parts Attention, Perception, & Psychophysics 71 (7), 1469-1477

Schira, M.M., Tyler, C.W., Breakspear, M., Spehar, B. (2009). The foveal confluence in human visual cortex. Journal of Neuroscience, 29 (28), pp. 9050-9058.

Solomon JA, Morgan MJ. (2009) Strong tilt illusions always reduce orientation acuity Vision research 49 (8), 819-824

Solomon, J. A. (2009, April). The histoof dipper functions.. Atten Percept Psychophys, 71(3), 435-443. doi:10.3758/APP.71.3.435

Tibber MS, Anderson EJ, Melmoth DR, Rees G, Morgan MJ. (2009) Common cortical loci are activated during visuospatial interpolation and orientation discrimination udgements PloS one 4 (2) e4585

Tibber MS, Grant S, Morgan MJ. (2009) Oculomotor responses and visuospatial perceptual judgments compete for common limited resources Journal of Vision 9 (12)

Tibber MS, Grant S, Morgan MJ. (2009) Oculomotor responses and visuospatial perceptual judgments

Tibber MS, Melmoth DR, Grant S, Morgan MJ. (2009) Eye movements and visuospatial perceptual extrapolations compete for common resources. Journal of Vision 9 (8), 397-397

Tomassini A, Morgan MJ, Solomon JA. (2009) Re-calibration of subjective reference frame in the tilt illusion Perception 38, 186-186

Turner, J., White E.M., Collins, M., Partridge, J.C. & Douglas, R.H. (2009) Vision in lanternfish (Myctophidae): adaptations for viewing bioluminescence in the deep-sea. Deep-sea Research 1. 56(6), 1003-1017

Tyler, C.W. (2009). Computing stereoscopic depth in natural images. Perception, 38 (6), pp. 888-889

Wagner, H.-J, Douglas, R.H., Frank, T.M., Roberts, N., Partridge, J.C. (2009) A novel vertebrate eye using both refractive and reflective optics. Current Biology 19, 1-.


Barbur JL and Spang K. (2008) "Colour constancy and conscious perception of changes of illuminant," Neuropsychologia. 46, 853-863 (2008)

Barbur JL, Rodriguez Carmona M, (2008) Harlow JA, Mancuso K, Neitz J, and Neitz M. "A study of unusual Rayleigh matches in deutan deficiency," Vis. Neurosci. 25, 507-516 (2008)

Bargary, G. & Mitchell, K. J. (2008). Response to Cohen Kadosh and Walsh: Synaesthesia: evaluating competing theories. Trends in Neurosciences, 31(11), 550-551

Bargary, G. & Mitchell, K. J. (2008). Synaesthesia and cortical connectivity. Trends in Neuroscience, 31(7), 335-42.

Barnett, K. J., Finucane, C., Asher, J. E., Bargary, G., Corvin, A. P., Newell, F. & Mitchell, K. J. (2007). Familial patterns and the origins of individual differences in synaesthesia. Cognition, 106(2), 871-93.

Chen, C.-C., Tyler, C.W. (2008). Excitatory and inhibitory interaction fields of flankers revealed by contrast-masking functions. Journal of Vision, 8 (4 ):10.1-14. doi: 10.1167/8.4.10.

Davis AR, Sloper JJ, Neveu MM, Hogg CR, Morgan MJ, Holder GE. (2008) Differential changes in color and motion-onset visual evoked potentials from both eyes in early-and late-onset strabismic amblyopia. Investigative Ophthalmology & Visual Science 49 (10), 4418-4426

Gheri C, Chopping S, Morgan MJ. (2008) Synaesthetic colours do not camouflage form in visual search Proceedings of the Royal Society B: Biological Sciences 275 (1636), 841-846

Hasegawa, E.I., Sawada, K.., Abe, K., Watanabe, K., Uchikawa, K., Okazaki, Y., Toyama, M. & Douglas, R.H. (2008) The visual pigments of a deep-sea myctophid fish (Myctophum nitidulum); an HPLC and spectroscopic description of a non-paired rhodopsin/porphyropsin system. Journal of Fish Biology 72 (4), 937-945

Hess, R.F., Baker, D.H., May, K.A. & Wang, J. (2008). On the decline of 1st and 2nd order sensitivity with eccentricity. Journal of Vision, 8(1):19, 1-12

Likova, L.T., Tyler, C.W. (2008). Occipital network for figure/ground organization. Experimental Brain Research, 189 (3), pp. 257-267

Mareschal I, Morgan MJ, Solomon JA. (2008) Contextual effects on decision templates for parafoveal orientation identification. Vision Research 48 (27), 2689-2695

Mareschal I, Solomon J, Morgan M. (2008) The opposite of crowding revealed using classification images. Journal of Vision 8 (6), 430-430

May, K.A. & Hess, R.F. (2008). Effects of element separation and carrier wavelength on detection of snakes and ladders: Implications for models of contour integration. Journal of Vision, 8(13):4, 1-23

Morgan M, Chubb C, Solomon J. (2008) The visual system removes sensory noise from the representation of a texture. Journal of Vision 8 (6), 692-692

Morgan M, Chubb C, Solomon JA. (2008) A 'dipper'function for texture discrimination based on orientation variance. Journal of Vision 8 (11)

Morgan MJ, Giora E, Solomon JA. (2008) A single "stopwatch" for duration estimation, A single "ruler" for size Journal of Vision 8 (2)

Rodriguez-Carmona M, Sharpe LT, Harlow JA, and Barbur JL, (2008) "Sex-related differences in chromatic sensitivity," Vis. Neurosci. 25, 433-440 (2008)

Spang K, Morgan M. (2008) Cortical correlates of stereoscopic depth produced by temporal delay. Journal of Vision 8 (9)

Tibber M, Elaine A, Rees G, Morgan M. (2008) The neural correlates of the 3-dot vernier task: Visuospatial extrapolation examined within the framework of a duplex model of vision. Journal of Vision 8 (6), 952-952

Tibber MS, Melmoth DR, Morgan MJ. (2008) Biases and sensitivities in the Poggendorff effect when driven by subjective contours. Investigative ophthalmology & visual science 49 (1), 474-478

Tomassini A, Solomon JA, Morgan MJ. (2008) When noisy means cardinal: visual biases for cardinal orientations revealed by degrading stimulus identity. Journal of Vision 8 (6), 270-270

Tyler, C.W., Kontsevich, L.L., Ferree, T.C. (2008). Independent components in stimulus-related BOLD signals and estimation of the underlying neural responses. Brain Research, 1229, pp. 72-89

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