Muriel Boucart
















  Bretagne : Pointe du Raz


Contact Information :

Faculté de Médecine de Lille
Pole Recherche
1 place de Verdun
59000 Lille (France)

Email : Muriel.Boucart@chru-lille.fr




Bretagne: menhir de Quintin

Short Biosketch



 I am a Research Director (Directeur de Recherche) at the National Center for Scientific Research (CNRS) and head of the research team Action- Vision-Apprentissage at the university Lille 2. I have a PhD in cognitive psychology from the university Paris 5 René Descartes entitled “Psychophysics of visual form perception: a neuropsychological approach” supervised by Pr C Bonnet and funded by the ministery of research and technologies. Following my PhD I worked two years as a post-doc (funded by Fondation Fyssen) in Pr GW Humphreys’s lab at the university of Birmingham (UK) where I worked on the impact of semantic information on the processing of physical properties (e.g., size, shape, orientation, colour..) of objects in healthy people and in neurologically impaired patients (with a visual agnosia). I was recruited as CNRS researcher in 1991 in the laboratory of experimental psychology (university Paris 5). From 1994 to 1999 I worked in the university hospital of Strasbourg (INSERM lab) on perceptual deficits in patients with schizophrenia and in psychopharmacology on the effect of benzodiazepines on the processing of contour information. I moved to Lille at the end of 1999 to build my own laboratory in cognitive neuroscience in the university hospital of Lille, associated to university Lille2–Law and Health.

Awards
1995 CNRS bronze medaille
1998 Prize of the Fondation for blind and visual handicapped people for a research on macular degeneration
2010 Prize of the Society of Science (prix Werteimer) of the city of Lille

Publications 


  • Boucart, M.  &  Bonnet,  C. (1990)  Stimulus  energy  affects  the detectability  of  visual  forms and  objects.  Bulletin  of  the Psychonomic Society, 28, p.415-417
  • Boucart, M., & Humphreys, G.W. (1990) Familiarity and  nameability do  not  affect picture detection. Bulletin  of  the  Psychonomic Society, 28, p.409-411
  • Boucart,  M.,  &  Bonnet,  C. (1991) A study  of  the  effect  of structural  information  and  familiarity  in  form   perception. Quarterly Journal of Experimental Psychology, 43A, 223-248.
  • Boucart, M. & Bruyer R. (1991) Influence of physical and semantic information  in a categorization task of  fragmented  pictograms. Perception, 20, 403-414.
  • Boucart,  M., & Humphreys, G.W. (1992 )  Global  shape cannot  be  attended without object  identification.  Journal  of Experimental Psychology: Human perception and Performance, 18, 785-806.
  • Boucart, M. & Humphreys, G.W. (1992) The computation of perceptual structure from collinearity and closure: normality and pathology. Neuropsychologia, 30, 527-546..
  • Boucart, M. & Humphreys, G.W. (1994) Attention to orientation, size, luminance and color: attentional failure within the form domain. Journal of Experimental Psychology: Human Perception and Performance, 20, 61-80.
  • Boucart, M., Delord, S., & Giersch, A. (1994) The computation of contour information in complex objects. Perception, 23, 399-409.
  • Boucart, M., Humphreys, G.W., & Lorenceau, J. (1995) Automatic access to object identity: attention to global information, not to particular physical dimensions, is important. Journal of Experimental Psychology: Human Perception and Performance, 21, 584-601.
  • Lorenceau, J., & Boucart, M. (1995) Paradoxical effects of a static textured background on motion integration. Vision Research, 35, 2303-2314.
  • Giersch, A., Boucart, M., Danion, J.M., Vidailhet, P., & Legrand, F. (1995) Effects of lorazepam on perceptual integration of visual forms in Healthy volunteers. Psychopharmacology, 119, 105-114..
  • Boucart, M., Grainger, J., & Ferrand, L. (1995) Three-dimensional features facilitate object recognition. Visual Cognition, 4, 451-478.
  • Humphreys, G.W., Boucart, M., Datar, V. & Riddoch, M.J. (1995) Processing fragmented forms and strategic control of orienting in visual neglect. Cognitive Neuropsychology, 13, 177-203.
  • Giersch, A., Boucart, M., Speeg-Schatz, C., Kauffman-Muller, F., & Danion, J.M. (1996) Lorazepam impairs perceptual integration of visual forms: a central effect. Psychopharmacology., 126, 260-270.
  • Humphreys, G.W., & Boucart, M.  (1997) Selection by color and form in vision. Journal of Experimental Psychology: Human Perception and Performance, 23, 136-153.
  • Giersch, A., Boucart, M., & Danion, JM. (1997) Lorazepam, a benzodiazepine, induces atypical distractor effects with compound stimuli: a role for line ends in the processing of compound letters. Visual Cognition, 4, 337-372..
  • Boucart, M., & Humphreys, G.W. (1997) Integration of physical and semantic information in object processing.  Perception, 26, 1197-1209. .
  • Wagemans, J. Notebaert, W., & Boucart, M. (1998) Lorazepam but not diazepam impairs identification of pictures on the basis of specific contour fragments. Psychopharmacology, 138, 326-333.
  • Boucart, M., Mobarek, N., Cuervo, C. & Danion, J.M. (1999)What is the nature of the increased Stroop interference in schizophrenia. Acta Psychologica, 101, 3-25
  • Boucart, M. (1999 Guest Editor) The neuroscience of perceptual integration. Visual Cognition, 6, 225-230.
  • Fuentes, L.J., Boucart, M., Vivas, A.B., Alvarez, R. & Zimmerman, M.A. (1999) Inhibitory Tagging in Inhibition of Return is Affected in Schizophrenia: Evidence from the Stroop Task. Neuropsychology, 14, 134-140.
  • Fuentes, L.J., Boucart, M., Vivas, A.B., Alvarez, R. & Zimmerman, M.A (2000) Inhibitory Processing in Visuospatial Attention in Healthy Adults, Medicated Schizophrenics and One Non-Medicated Schizophrenic Patient. Schizophrenia Research, 40, 75-80..
  • Boucart, M., Meyer, M.E.,  Pins, D., Humphreys, G.W.,Gounod, D. & Foucher, J. (2000) Automatic object identification: a fmri study. Neuro Report, 11, 2379-2383.
  • Boucart, M., de Visme, P., & Wagemans, J. (2000) Effect of benzodiazepine on temporal integration in object perception. Psychopharmacology, 3, 249-255.
  • Moroni, C., Boucart, M., Humphreys, G.W., Henaff, M.A., & Belin, C. (2000) Failure to identify the target does not prevent the attentional blink effect. Neuro Report, 11, 2775-2780.
  • Elliott, MA, Becker, C., Boucart, M, & Muller, HJ (2000) Enhanced GABAA inhibition enhances synchrony coding in human perception. Neuro Report, 11, 3403-3407.
  • Giersch, A., Humphreys, G.W., Boucart, M.& Kovacs, I. (2001)  The computation of occluded contours in visual agnosia: evidence for early computation prior to shape binding and figure/ground coding. Cognitive Neuropsychology, 17, 731-759.
  • Beckers, T., Wagemans, J. & Boucart, M. & Giersch, A. (2001) Different effects of lorazepam and diazepam on perceptual integration. Vision Research, 41, 2297-2303.
  • Speeg-Schatz, C., Giersch, A., Boucart, M., Gottenkiene, S., Tondre, M., Kauffman, F., & Danion, J.M. (2001) Visual effect of lorazepam on the oculomotor balance. Binocular Vision, 16, 99-104.
  • Michael, G.A., Boucart, M., Degreef, J.-F., Godefroy, O. (2001) The thalamus interrupts top-down attentional control for permitting exploratory shiftings to sensory signals. Neuroreport,12, 2041-48.
  • Moroni, C., Boucart, M., Ferry, P., Claes, T., & Belin, C. (2002) Is the attentional blink effect located in short term memory? Brain & Cognition, 48, 475-479.
  • Giersch, A., Danion, JM., Boucart, M., Roeser, C., & Abenhaim, K. (2002) Reduced or decreased influence of non-pertinent information in patients with schizophrenia. Acta Psychologica,111, 171-190.
  • Boucart, M., Biederman, I., Cuervo, C., Danion, JM, & Wagemans, J (2002) A Study of the effect of benzodiazepines on structural and semantic memory. Psychopharmacology, 165, 43-50.
  • Silvert, L., Naveteur, J., Honoré, J., Sequeira, H.  & Boucart, M. (2004) Emotional stimuli in rapid serial visual presentation: Repetition blindness and immediate recall. Visual Cognition, 11, 433-460.
  • Pins, D. Meyer, ME. , Foucher, J. Humphreys, GW. & Boucart, M. (2004) Neural correlates of covert object identification. Neuropsychologia, 42, 1247-59
  • Delord S, Ducato MG, Pins D, Devinck F, Thomas P, Boucart M, &  Knoblauch K (2006) Psychophysical assessment of magno- and parvocellular function in schizophrenia. Visual Neuroscience, 23, 645-50.
  • Michael GA, Garcia, S, Fernandez D, Sellal F & Boucart M (2006) The ventral premotor cortex (vPM) and resistance to interference. Behavioral Neuroscience, 120, 447-462.
  • Naïli F., Despretz P & Boucart M. (2006) Colour recognition at large visual eccentricities in normal observers and patients with low vision Neuroreport, 17, 1571-74.
  • Boucart, M, Waucquier N, Michael GA & Libersa C (2007) Diazepam impairs the temporal dynamic of visual attention.  Experimental & Clinical Psychopharmacology, 15, 115-122.
  • Deltour, L., Berquin, P., Quaglino, V., Vernier, MP, Despretz, P. & Boucart, M. (2007).Children with Benign Epilepsy with Centrotemporal Spikes (BECTS) Show Impaired Attentional Control: Evidence from an Attentional Capture Paradigm.  Epileptic Disorders, 9, 32-38.
  • Ducato, MG, Thomas, P, Monestes, JL, Despretz, P, & Boucart M.  (2008) Attentional Capture in Schizophrenia and Schizotypy: Effect of Attentional Load. Cognitive Neuropsychiatry, 13, 89 - 111.
  • Ducato, MG, Michael GA, Thomas P, Despretz, P, Monestes JL, Loas G, & Boucart M (2008) Attentional capture in schizophrenia: failure to resist interference from motion signals. Cognitive Neuropsychiatry, 13, 185 - 209.
  • Boucart M, Dinon JF, Despretz P, Desmettre T, Hladiuk K, & Oliva A.(2008) Recognition of facial emotion in age related macular degeneration (AMD): a flexible usage of facial features. Visual Neuroscience, 25(4):603-9.
  • Boucart M, Despretz P, Hladiuk K, & Desmettre T (2008) Does context or colour improve object recognition in patients with macular degeneration? Visual Neuroscience, 25, 685-91.
  • Giersch A, Boucart M, Elliott M & Vidhaillet P (2009) Atypical behavioural effects of lorazepam: Clues to the design of novel therapies?. Pharmacology & Therapeutics, 126, 94-108.
  • Boucart M, Moroni C, Despretz P, Pasquier F & Fabre-Thorpe M. (2009) Rapid categorization of faces and objects in a patient with impaired object recognition. NeuroCase, 25: 1-12.
  • Naili F, Boucart M, Derambure P & Arndt C. (2009) Visual impairment at large eccentricity in participants treated by vigabatrin: visual, attentional or recognition deficit ? Epilepsy Research, 87(2-3):213-22.
  •  Jebara N, Pins D, Despretz P, Boucart M. (2009) Face or building superiority in peripheral vision reversed by task requirements. Adv Cogn Psychol.;5:42-53.
  • Godefroy O, Spagnolo S, Roussel M & Boucart M (2010) Stroke and action slowing: mechanisms, determinants and prognosis value. Cerebrovasc Disease; 29:508-514
  • Godefroy O, Roussel M, Despretz P, Quaglino V, Boucart M. (2010) Age-Related Slowing: Perceptuomotor, Decision, or Attention Decline? Exp Aging Res. Apr;36(2):169-189.
  • Boucart M, Naili F, Despretz P, Defoort S & Fabre-Thorpe M (2010) Implicit and explicit object recognition at very large visual eccentricities : no improvement after loss of central vision. Visual Cognition, 18(6), 839-58.
  •  Marques A, Dujardin K,  Marques A, Dujardin K, Boucart M, Pins D, Delliaux M, Defebvre L, Derambure P, Monaca C. (2010) REM sleep behaviour disorder and visuoperceptive dysfunction: a disorder of the ventral visual stream? J Neurol. 257(3):383-91.
  •  Bailon O, Roussel M, Boucart M, Krystkowiak P, Godefroy O. (2010) Psychomotor slowing in mild cognitive impairment, Alzheimer's disease and lewy body dementia: mechanisms and diagnostic value. Dement Geriatr Cogn Disord.;29(5):388-96.
  • Tran THC, Rambaud C,  Despretz P & Boucart M (2010) Scene perception in age-related macular degeneration (AMD). Invest Ophthalmol Vis Sci. 2010 Dec;51(12):6868-74.
  • Laprévote V, Oliva A, Delerue C, Thomas P, Boucart M. (2010) Patients with schizophrenia are biased toward low spatial frequency to decode facial expression at a glance. Neuropsychologia.;48(14):4164-8.
  • Delerue C, Laprévote V, Verfaillie K, Boucart M. (2010) Gaze control during face exploration in schizophrenia. Neurosci Lett., 482(3):245-9.
  • Tran THC, Guyader N, Guérin A, Despretz P & Boucart M (2011) Figure ground discrimination in age related macular degeneration Invest Ophthalmol Vis Sci. ;52(3):1655-60.
  • Tran THC & Boucart M (2012) Objects and scene perception in Age-Related Macular Degeneration.  J Fr Ophtalmol. 2012 Jan;35(1):58-68.
  • Delerue C & Boucart M (2012) The Relationship between visual exploration and action processing in schizophrenia. Cogn Neuropsychiatry  Jul;17(4):334-50.
  • Tran THC, Despretz P, & Boucart M. (2012) Scene perception in macular degeneration: the effect of contrast. Optom Vis Sci. 2012 Apr;89(4):419-25.
  • Delerue C & Boucart M. (2013) Visual scan paths of patients with schizophrenia in picture viewing tasks.  Cogn Neuropsychiatry. 2013 May;18(3):153-67.
  • Lenoble Q, Bordaberry P, Rougier MB, Boucart M & Delord S. (2013) Visual Impairment in Normal Aging : a Dissociation between Magnocellular and Parvocellular Processing in a categorization Task. Exp Aging Res. 2013;39(2):145-61.
  • Boucart M, Moroni C, Szaffarczyk S & Tran THC. (2013) Implicit processing of scene context in macular degeneration. Invest Ophthalmol Vis Sci. 2013 Mar 15;54(3):1950-7.
  • Delerue C, Hayhoe M & Boucart M (2013) Eye movements during natural actions in schizophrenia. J Psychiatry Neuroscience. 2013 Apr 3;38(3): 120143. doi: 10.1503/jpn.120143. [Epub ahead of print]
  • Boucart M, Moroni C, Thibault M, Szaffarczyk S & Greene M (2013) Scene categorization at large visual eccentricity. Vision Research. 2013 Apr 15;86C:35-42.
  • Laprevote V, Oliva A, Ternois AS, Schwan R, Thomas P, Boucart M. (2013) Low Spatial Frequency Bias in Schizophrenia is Not Face Specific: When the Integration of Coarse and Fine Information Fails. Front Psychopathology. 2013 May 6;4:248.
  • Delerue C & Boucart M (2013) Imagined motor action and eye movements in schizophrenia. Front Psychopathology. 2013 Jul 12;4:426.
  • Boucart M, Bubbico G, Szaffarczyk S, & Pasquier F (2014) Animal spotting in Alzheimer’s disease: An eye tracking study of object categorization. J Alzheimers Dis. 2014;39(1):181-9. doi: 10.3233/JAD-131331.
  • Plomhause L, Dujardin K, Boucart M, Herlin V, Defebvre L, Derambure P, & Monaca-Charley C (2014) Impaired visual perception in Rapid Eye Movement Sleep Behavior Disorder. Neuropsychology. 2014 May;28(3):388-93.
  • Querné L, Fall S, Le Moing A G, Delignières A, Simonnot  A, Bourgueil Thierry, de Broca  A, Gondry C, Boucart M, & Berquin P. (in press) Effects of methylphenidate on default-mode network/task-positive network synchronization in children with attention deficit hyperactivity disorder performing a visuospatial flanker task. J Attention Disorders. 2014 Jan 13. [Epub ahead of print]
  • Thibaut M, Tran THC, Szaffarczyk S, & Boucart M. (2014) The contribution of central and peripheral vision in scene categorization: a study on people with central vision loss. Vision Res. 2014 May;98:46-53.
  • Tran THC, Despretz P, & Boucart M. (2014) Short term visual memory and space representation in age-related macular degeneration (AMD). Optom Vis Sci. 2014 Aug;91(8):1012-20. 
  •  Boucart M, Calais G, Lenoble Q, Moroni C & Pasquier F (2014) Differential processing of natural scenes in typical and atypical Alzheimer disease measured with a saccade choice task. Front Integr Neurosci. 2014 Jul 25;8:60. doi: 10.3389/fnint.2014.00060. eCollection 2014.
  • Boucart M, Michael GA,  Bubicco G, Ponchel A,  Waucquier N, Deplanque D,  Deguil J & Bordet R (2015) Cholinergic modulation of stimulus-driven attentional capture. Behavioral Brain Research, 283,  47–52.
  • Lenoble Q, Tran TH, Szaffarczyk S, Boucart M. (2015) Categorization Task over a Touch Screen in Age-Related Macular Degeneration. Optom Vis Sci. 2015 Oct;92(10):986-94.

  • Kenigsberg PA, Aquino JP, Berard A, Boucart M, Bouccara D, Brand G, Charras K, Garcia-Larrea L, Gzil F, Krolak-Salmon P, Madjlessi A, Malaquin-Pavan É, Penicaud L, Platel H, Pozzo T, Reintjens C, Salmon É, Vergnon L, Robert P. (2015) Geriatr Psychol Neuropsychiatr Vieil. 2015 Sep 1;13(3):243-258.

  • Thibaut M, Tran TH, Delerue C, Boucart M. (2015) Misidentifying a tennis racket as keys: object identification in people with age-related macular degeneration. Ophthalmic Physiol Opt. 2015 May;35(3):336-44.

  • Boucart M, Delerue C, Thibaut M, Szaffarczyk S, Hayhoe M & Tran THC (2015) Impact of wet macular degeneration on the execution of natural actions. Invest Ophthalmol Vis Sci. 2015 Oct 1;56(11):6832-8
  • Boucart M,  Bubicco G, Szaffarczyk S, Defoort S, Ponchel A, Waucquier N, Deplanque D, Deguil J &  Bordet R.(2015) Donepezil increases contrast sensitivity for the detection of objects in scenes. Behav Brain Res. 2015 Jul 7;292:443-44.
  • Boucart M, Delerue C, Thibaut M, Szaffarczyk S, Hayhoe M & Tran THC (2015) Impact of wet macular degeneration on the execution of natural actions. Invest Ophthalmol Vis Sci. 2015 Oct 1;56(11):6832-8.
  • Lenoble Q, Bubbico G, Szaffarczyk S, Pasquier F, Boucart M.(2015) Scene categorization in Alzheimer's disease: a saccadic choice task. Dement Geriatr Cogn Dis Extra. 2015 Jan 16;5(1):1-12.

  • Dive S, Rouland  JF,  Lenoble Q, Szaffarczyk S,  McKendrick A &  Boucart M. (2016 in press) Impact of peripheral field loss on the execution of natural actions: a study with glaucomatous patients and normally sighted controls. J of Glaucoma.

  • Boucart M, Lenoble Q, Quettelart J, Szaffarczyk S,  Despretz P & Thorpe SJ. (2016 in press) Finding faces, animals and cars in far peripheral vision. Journal of Vision



Courses


Master 1 and Master 2 Cognitive Neuroscience : visual perception from physiology to cognitive processes  University Lille2

Master 2 neuropsychology University Lille3 and university Aix en Provence : visual perception: anatomy of the visual system, visual objects, face and scene processing including studies in animals, neuroimaging in healthy people and pathologies affecting the retina and  the brain.

DU Neuro-psycho-pharmacology university Lille2 : the effect of benzodiazepines on cognition


PhD students


Anne Giersch : PhD in neuroscience University Louis Pasteur Strasbourg (1997).

Christine Moroni : PhD in cognitive psychology  University Lumière Lyon 2 (2002)

Georges-Andrew Michael : PhD in neuroscience  university Lyon 1 (2003)

Maria-Giovanna Ducato : PhD in neuroscience university Lille2 (2006)

Fatima Naili: PhD in neuroscience university Lille2 (2006)

Céline Delerue : PhD in neuroscience university Lille2 (2010)

Vincent Laprévote : PhD in neuroscience university Lille2 (2010)

Tran Thi Ha Chau:  PhD in neuroscience university Lille2 (2011)

Giovanna Bubbico :  PhD in neuroscience university Chieti (2013)

Miguel Thibaut:  PhD in neuroscience university Lille2 (2015)


Main Collaborators

Michèle Fabre-Thorpe(Lab. CerCo Toulouse): http://www.cerco.ups-tlse.fr/fr_vers/annuaire/michele_fabre_thorpe.htm

Eric Castet (Institut Neurosciences Cognitives de la Méditerranée) : http://www.incm.cnrs-mrs.fr/pperso/ecastet.php

Mary Hayhoe (Center for Perceptual Systems): http://www.psy.utexas.edu/psy/faculty/Hayhoe/hayhoe.html

Lester Loschky Department of Psychological Sciences 471 Bluemont Hall Kansas State University USA

Allison McKendrick Optometry and Vision Science, university of Melbourne, Australia

Antje Nuthmann department of psychology university of Edinburg UK

Carole Peyrin Laboratoire de Psychologie & NeuroCognition (LPNC) universite Pierre Mendes-France - Grenoble II, France


MAIN GRANTS


EEC BIOMED   (N°PL962775) "Visual object recognition: cognitive neuropsychological, psychopharmacological and neuroimaging (PET and fMRI) studies". In collaboration with Danemark  (Pr Anders Gade Coord., Pr Olaf Paulson, Pr Lars Kai Hansen) and UK (Pr Glyn Humphreys).1997-1999.

INSERM: "Visual deficiencies at extreme ages" 1999-2001.

COGNITIQUE-CNRS « Efficiency and consciousness of peripheral object perception: an application to age-related macular degeneration »  1999-2002 with M.Fabre-Thorpe (coord Toulouse)

PHRC 2002: « Schizophrenia and visual information processing » with P. Thomas (coord Lille)

CNRS Interdisciplinary Program « Visually impaired people : maculopathies and electronic devices» with JC Kastelik (coord Valenciennes) & JC Sperandio 2003-2005

CNRS  research program Aging and Longevity :  « Spatial Vision in people with macular degeneration M Boucart (Coord) with N Guyader (Grenoble) (2008)

ANR 2009-11 Programme Maladies Neurologiques et Psychiatriques : « Alzheimer: perception of objects in their natural environment » with M Fabre-Thorpe (Coord Toulouse) and S Delord (Bordeaux).

Feder-Europe-Region 2009-2010 « Acetylcholine and vision : from perception to spatial cognition (M Boucart Coord) with R Bordet, F Pasquier et K Dujardin (Lille).

ANR 2011-14 SHS2 programme LowVision: "Perceptual and cognitive processes after partial or total loss of macular vision : towards a more ecological approach".

Fondation Visio « The contribution of central and peripheral vision to spatial cognition: visual exploration and instrumental activities. 2013-2014. Financement 1 an de post-doctorant (37 KE)


Research Interests


1)  The capabilities of peripheral vision at large visual eccentricities :

   (Collaboration with Aude Oliva (MIT Boston) and Michelle Greene (university Stanford)

 

The functions of peripheral vision for perception and interpretation of the surrounding environment remain largely unknown. Because its low spatial resolution is believed to make it un-adapted to fine discrimination necessary for objects, faces and words identification, peripheral vision has been the object of few investigations in this domain. Moreover, for technical reasons (e.g., the size of computer screens) few studies have investigated peripheral vision above 20° eccentricity. Following Thorpe et al. (2001 Eur J Neuroscience) study on rapid categorization at large visual eccentricities, we (Naili et al., 2006; Boucart et al. 2010) have demonstrated implicit recognition (measured by priming effects) but no explicit recognition of coloured photographs of objects at 50° eccentricity whilst both explicit and implicit recognition occurred at 30° eccentricity in normally sighted young observers and in 4 patients with Stargardt disease (a juvenile maculopathy inducing central vision loss). Semantic categorization (e.g., to decide whether an object is edible or not) was above chance at 30° but not at 50° eccentricity. These results suggest that some categorization tasks, involving objects and scenes, can be performed in peripheral vision, as long as they require features that are within the resolution limit of the periphery. We are currently investigating the capabilities of peripheral vision for object and scene recognition, its contribution to scene memory representations, crowding effects in natural scenes, figure/ground segregation, and perceptual learning at large visual eccentricities with both normally sighted observers and with patients with either central (maculopathies) or peripheral field loss (tunnel vision). To this aim, we have designed a panoramic hemispheric screen (5m diameter) on which photographs of either isolated objects or scenes or scenes covering the whole screen (see Figure) are displayed from 0 to 90° eccentricity.

Panoramic screen (5m diameter): Right: an example of scenes displayed from 10 to 80° eccentricity in a spatial forced choice paradigm. Central fixation is controlled by an infrared camera. Left: an example of an indoor scene covering the whole visual field in which participants can navigate (forward/backward or left/right) with a joystick to find an object.

 

2) Object and scene perception in people with low vision :

(Collaboration with Eric Castet Institut des Neurosciences Cognitives de la Méditerranée and Nathalie Guyader & Anne Guérin Lab GIPSA Grenoble)

The number of pathologies related to age is in constant progression in western countries. Notably, age related macular degeneration (AMD), inducing a central vision loss, affects about 1 million people in France. AMD is a pathology that gradually reduces sight without warning as its progression is painless. Because macular degeneration usually begins slowly and asymmetrically on the two eyes, many people do not immediately realize that they are progressively losing their sight. There are two types of macular degeneration: wet (neovascular or exudative) and dry (atrophic). Both wet and dry macular degeneration have similar symptoms (see Figure 2). AMD affects the region of the retina with the highest density of receptors: the macula, about 6 mm in diameter, covering the central 15-20° of the visual field. As the macula is responsible for high spatial resolution, the patients’ ability to obtain information about the environment is reduced to peripheral vision, which is characterized by low spatial resolution as the density of receptors decreases with eccentricity. People with AMD report increased difficulties for everyday tasks like reading, driving, cooking, watching TV, recognizing faces and facial expressions, recognizing pictures and finding objects especially when the illumination level is low  Vision-related Quality of Life report that patients suffering from AMD also encounter more difficulties than do age matched normally sighted individuals when shopping (i.e., finding objects on shelves), managing money, preparing meals and performing light housework.


 AMD clinical signs

   


          


Reduction of contrast sensitivity







Reduction of visual acuity







Metamorphopsia: straight lines appear curved






Central scotoma






As reading and face perception are the most common clinical complaints of patients with AMD seeking visual rehabilitation few investigations have been conducted on how these people perceive objects and scenes. Our team in Lille has conducted a series of experiments on object and scene categorization in people with AMD. With centrally displayed stimuli we have shown :

- that object categorization in scenes was accomplished more accurately with coloured than with grey level photographs in patients with AMD; consistent with the idea that colour helps segmentation.

- that isolated objects were better recognized than objects in scenes suggesting a higher sensitivity to crowding and lateral masking in low vision.

- that the object does not have to be totally isolated (i.e., an object on a uniform background) for patients to categorize it more efficiently. A white rectangle separating the object from the scene is sufficient to improve recognition.

- that people with AMD can categorize scenes on the basis of global spatial properties with high accuracy

 

These results suggest that rehabilitation procedures, technical devices and magazines for people with low vision should use spatial properties that facilitate image segmentation like colored surfaces, enhanced contours and increased spacing between target and background or target and surrounding objects.

 

These studies are only the beginning of investigations on the perception of natural environments in people with low vision in general, and in people with macular degeneration in particular. A lot of questions remain to be investigated like, for instance, what are the mechanisms underlying impaired recognition of an object in a scene by people with AMD: figure/ground segregation, the association of an object to its proper context, access to object representations? What level of representation is impaired in the ventral stream? Would the deficit be stronger in a task requiring recognition rather than detection or categorization? Are spatial representations impaired in people with central vision loss? Answers to these questions will require both behavioural and brain imaging studies.