Jean-Baptiste BERNARD

INCM
31 chemin J. Aiguier 
13402 Marseille Cedex 20
Phone: 33 (0) 4 91 16 46 53.
Fax: 33 (0) 4 91 16 49 69.
Email: bernard@incm.cnrs-mrs.fr

Since October 2005 and until the end of 2008, I’m doing a PhD under the supervision of Dr Eric Castet in a neuroscience French laboratory “Institut de Neurosciences Cognitives de la Méditerranée” (INCM) located in Marseille, France.

Before, I obtained 2 masters of engineering and science with majors in mathematics, computer science and imaging (see my CV here)

Research interests

We try to understand the difficulties for patients who cannot use their central vision in page-mode reading (AMD patients...). Our final purpose is to find some ways to enhance or customize text display to improve the comfort and the reading  performance.

         
  A central scotoma: A hole at the center of the visual field

 

   

My research is focused on :

1. The simulation of an artificial central scotoma

Using an eyetracker, we simulate an exact absolute scotoma (characterized by texture, size or shape). Therefore, we can simulate a normal page reading without central vision.
 
Using the artificial scotoma paradigm, we studied the interline effect in peripheral reading ( Page mode reading with simulated scotomas: a modest effect of interline spacing on reading speed, Vision Research, 2008 May; 48(10):1280), and oculomotor strategies of subjects with simulated central scotomatas. (Page mode reading with simulated scotomas: Oculo-motor patterns, Vision Research, in Press)

   A normal-sighted subject with a central scotoma
 
     
Reading with a square central scotoma 
 
Our last experiment (presented at Vision 2008) about word recoginition shows the difficulty for subject without central vision to integrate information across saccades.
 

    2.  Clinical Studies

We're studying patients in an experimental room in the low vision center of the hospital "La Timone" in Marseille. We're using micro-perimetry to characterize scotoma and computer-based tests  to characterize their reading performance.

A micro- perimetry to define the scotoma of a patient


Reading performances of a patient
 
We showed that the effect of interline spacing is the same with patients or simulated subjects. (Poster presented at Vision 2008)

3.  Navisio: A software to improve complex documents reading for low vision people

Navisio is developped in collaboration with the INRIA (Institut National de Recherche en Informatique et Automatique, Pierre Kornprobst & Emilien Tlapale) in Sophia Antipolis.
Our purpose is to improve performance and comfort for low vision patients with electronic documents. We use a double-window presentation to help low vision reader to navigate.
In the normal view, the reader can select a part of the text like a paragraph. The text will be reformatted in the enhanced view: a lot of display parameters can be changed (character size, interline spacing, scrolling, colours).
A layout analyse allows to display connected paragraphs.
 
Navisio has been tested in the hospital “La Timone” where most patients enjoyed it :-)
 
    The normal view

   The  parametrizable enhanced view
 
Navisio is regularly improved with new options. It will be next disposable for free. To know more, it's here!
   

4.  An ideal observer model of reading letters, words and text with a damaged visual field

Recently, with Fermin Moscoso Del Prado Martin (from Laboratoire de Psychologie Cognitive in Marseille), we developped an ideal bayesian observer model of single word reading in normal readers and central scotoma patients.
Using this technique we are able to predict the spatio-temporal pattern of saccades in terms of pixels. This enables us to contrast theories that are impossible to compare using the traditional letter-slot approaches to modelling reading.


                        The pixel-based prior


The optimal position (in dark red) for the first fixation with a square-shaped scotoma (a fixation over or under the word is the most interesting to extract information with only one fixation).

To know more, it's here.
   

Collaborations

LPC (Françoise Vitu, Fermin Del Prado Martin, researchers), ESSILOR (Anne-Catherine Scherlen, researcher), INRIA (Emilien Tlapale, PhD student, Pierre Kornprobst, researcher),  Hopital de la Timone (Géraldine Faure, orthoptiste)

Communications

    Bernard JB, Castet E (2008)
Effect of syllabic segmentation with colors on visual French word recognition time studied with a simulated central scotoma
Vision 2008, Montreal, Canada

Scherlen AC, Bernard JB, Castet E (2007)
Page mode reading with simulated scotomas : Oculo-motor patterns
Vision Research, in Press
Bernard JB, Tlapale E, Castet E, Kornprobst P (2008)
Navisio, a software to help low-vision patients to read PDF documents
French Society of Ophtalmology – Paris, France

Bernard JB, Scherlen AC, Castet E (2007)
Page mode reading with simulated scotomas : a modest effect of interline spacing on reading speed
Vision Research, 47(28):3447-59

Bernard JB, Scherlen AC, Castet E (2007)
Vertical interline spacing is not a major limiting factor of reading speed with a central artificial scotoma
European Conference on Visual Perception, Arezzo, Italia

Bernard JB, Scherlen AC, Castet E (2007)
Effect of line spacing on reading speed in normally-sighted subjects with an artificial scotoma
Vision Science Society 2007, Sarasota, Florida
Société Française des Neurosciences 2007, Montpellier, France

Tlapale E, Bernard JB, Castet E, Kornprobst P(2006)
A Gaze-Contingent system to facilite reading for patients with central scotomatas
INRIA Technical Report RT-0326

   

 A tool to extract sentences from numeric books:

 For our experiments, we need to extract sentences from numeric books, with strict constraints about number of characters, number of words, frequency of words and punctuation... iif you're interesting about this useful tool contact us!

The numeric book

The extracted sentences

I'm always strongly interested in travels, pictures and sea-fishing ;-)