published in Forum Express
12 décembre 2007
'The only limits with this device are the ones set by the researcher': Daniel Chebat
“It’s the first time I make my way across a cluttered course of several meters without the help of my cane,” explains 35-year-old M.L. who has been blind since birth. He accomplished this thanks to a device mounted on his tongue, which creates a mental image of the space around him.
In a video recorded by Daniel Chebat, PhD student in experimental neuropsychology at the Université de Montréal School of Optometry, M.L. is seen making his way down a hallway while avoiding a block on his left, a pipe on his right and the low wall by his feet. This is possible thanks to a camera mounted on his glasses which transmits images to a 144-pixel unit on his tongue.
The Tongue Display Unit (TDU) was tested for the first time in the summer of 2006 on a 14-meter course in Montreal. It proved to be remarkably efficient. “The 15 blind people from birth we tested showed extraordinary ability after just a few hours of training,” explains the 28-year-old Chebat. M.L., an engineer himself, said he looked forward to having a similar device, while other test subjects added that such a device could eventually replace their white cane.
Chebat explains that this is not about making the blind see. The vision of the blind is not modified by the TDU and remains at approximately 1/90. But the TDU allows them to recognize simple shapes in their surrounding environment thanks to the electrical charges transmitted on their taste buds.
“We are doing basic research and our experiment confirms what we intended to demonstrate regarding the activation of the visual cortex. It’s fascinating: the brain of the blind processes the data coming from the TDU as if it were visual data,” explains Chebat who works under the supervision of Professor Maurice Ptito who is well known for his work on neuronal plasticity.
The device used for this experiment was developed by Professor Paul Bach-y Rita of the University of Wisconsin-Madison and it quickly interested Professor Ptito. The success Ptito obtained won him international acclaim as well as substantial funding.
Ptito is the recipient of the Colonel Harland Sanders Chair in Vision Sciences. The funding allowed him to set up research labs and to build testing courses at the School of Optometry in Montreal and at the Hvidovre University Hospital in Denmark where teams of four people work under his supervision.
Chebat is currently leading three research projects in Canada and Denmark, which will eventually be the focus of scientific articles. The project in which M.L. participated is about to be published while the two other projects are still at the experimental stage.
In the second project, he wants to explore the sensory acuity of the blind within the confines of a complex course made up of five corridors. The third project, intends to immerse users of the TDU in a video game. The test subject will be asked to maneuver inside a virtual environment transmitted onto his taste buds while a scanner observes his brain.
The observation of the brain during use of the TDU has yet to be done. “The only limits with this device are the ones set by the researcher,” says Chebat who is thrilled by the development of his research.
Researcher:
Daniel Chebat
E-mail:
dr.chebat@umontreal.ca
Telephone:
514 343-6111 , extension 4532
Funding:
Canadian Institutes of Health Research
Tuesday, February 26, 2008
Society for Neuroscience 2007 Press Book Release
Dear Readers,
For the second consecutive year my abstract was selected to be part of the press book release of the prestigious SfN meeting which took place in San Diego (Nov. 3-7th). Here is a copy of the abstract that was released to the media:
Navigation Skills in the Early Blind Using a Tongue Stimulator.
D-R. Chebat, C. Rainville, K. Madsen, O. Paulson, M., Ptito
Univ. Montreal, Montreal, Canada.
Danish research center fo Magnetic Resonance, Hvidovre Hospital, Hvidovre, Denmark
Program Number: 737.24
Session Date-Time:Tuesday Nov., 6, 1:00 PM
WW17
Navigation is a complex behavior involving a multitude of sensory modalities. Vision is an integral component in navigation, providing the traveler with information about the configuration of proximal and distal space as well as updating motion cuess. The hippocampus has been shown to be involved in visual spatial memory in primates and humans. This brain structure comprises cells that respond to locations that are called place cells. Spatial navigation depends, in part, upon place celle actitivuty in teh hippocampus that plays a fundamental role in the interpretation of visual-based information. The hippocampus is subject to plastic changes humans. For example taxi drivers who have had an extensive visual navigational training show an enlarged right hippocampus whereas lesions to this same region impair retrieval and learning of spatial routes. Topographical memory relies on a network of brain regions involving the hippocampus, visual cortex, frontal lobes and parietal regions. Blind individuals from birth, however, are not impaired on a spatial competenmce level or in the formation of novel spatial maps of the environment when using tactile, proprioceptive or auditory cues. We recently showed, using a technique called Voxel-Based Morphometry (VBM) carried out on whole brain magnetic resonance imaging scans (MRI) that born blind people have a reduced right posterior hippocampus . The question therefore arisses on how blind people form spatial maps of their environment?
We first tested the ability of blind subjects to navigate in an obstacle course. Wearing a camera mounted on glasses and the tongue display unit (TDU) grid on the tongue, they were requested to point to the obstacle (detection), and move towards it and negotiate a path around it (avoidance). We shoed that blind subjects had no difficulty to peform teh task besides a structurally atrophied right posterior hippocampus (see 'Chebat et al., 2007a).
We proposed that they probably relied on other brain structures belonging to the neural network involved in topographical memory. We emphasied the use of neural pathways that connect teh parietal and frontal cortices to the occipital lobe because they are enlarged in the blind compared to the sighted. In a virtual maze task where subjects used their tongue to move along a virtual path while in a 3.0T fMRI scanner, we were able to show that route forming in the blind did not deoend upon the hippocampus but rather on cortical areas.
These results are of great interest since tehy show that the tongue is a useful organ to move around in the environment and to do so, it calls on a reorganization of brain connections that involve the frontal and parietal cortices. The applications of the TDU are therfore important since objects in the enviironment can be signaled to teh tongue in any non-vision situations lie darkness. Tests are currently on their way in deep sea divers wearing infra red goggles and tehir ability to use their tongue as a signal detector.
Wednesday, November 28, 2007
Des aveugles marchent grâce à un œil… sur la langue
26 novembre 2007
Daniel Chebat réussit à aider des aveugles à se déplacer sans canne
«C’est la première fois que je me déplace sans canne sur un trajet de plusieurs mètres semé d’obstacles», lance M.L., un aveugle de naissance de 35 ans, après avoir testé un dispositif qui lui permet de se faire une représentation mentale de l’espace grâce à sa langue. Dans l’extrait vidéo enregistré par Daniel Chebat, étudiant au doctorat en neuropsychologie expérimentale à l’École d’optométrie, on peut voir M.L. avancer dans un couloir en évitant minutieusement un bloc à sa gauche, un tuyau à sa droite et un muret à ses pieds. Une caméra fixée à des lunettes transmet les images sur un écran de 144 pixels directement déposé sur sa langue.
Un aveugle s’oriente dans le labyrinthe de l’Université de Montréal à l’aide de la Tongue Display Unit.
Expérimenté pour la première fois à l’été 2006 le long d’un parcours de 14 mètres à Montréal, le dispositif lingual (Tongue Display Unit ou TDU) s’est révélé d’une remarquable efficacité. «Les 15 aveugles de naissance qui ont participé à l’expérience ont montré une habileté extraordinaire après tout juste quelques heures d’entrainement», signale le jeune chercheur de 28 ans. M.L, lui-même ingénieur, a dit qu’il avait hâte de pouvoir se procurer un dispositif semblable, et d’autres ont indiqué que ce dispositif pourrait éventuellement remplacer leur canne blanche.
Il ne s’agit pas de redonner la vue aux aveugles, précise Daniel Chebat. La vision des non-voyants n’est pas modifiée par la TDU et demeure autour de 1/90. Mais le dispositif lingual leur offre l’occasion de reconnaitre des formes simples dans leur environnement par des influx électriques transmis sur leurs papilles. «Nous faisons principalement de la recherche fondamentale et notre expérience confirme ce que nous voulions démontrer sur l’activation du cortex visuel. C’est absolument fascinant: le cerveau des aveugles traite les informations de la TDU comme si c’était de l’information visuelle», explique Daniel Chebat, qui travaille sous la direction de Maurice Ptito, professeur à l’École d’optométrie reconnu pour ses études sur la plasticité neuronale.
Des locaux aménagés
La Tongue Display Unit a été mise au point par le professeur Paul Bach-y Rita, de l’Université du Wisconsin, et a rapidement suscité l’intérêt du professeur Ptito. Les succès que celui-ci a obtenus avec la TDU lui ont valu une visibilité internationale (voir Forum du 15 janvier 2007)… et d’importantes subventions. M. Ptito est notamment devenu titulaire de la Chaire Colonel-Harland-Sanders en sciences de la vision de l’UdeM, dotée d’un capital de 1,2 M$. Les sommes reçues ont permis d’aménager de vastes locaux de recherche et de construire des parcours à l’École d’optométrie et à l’hôpital de l’Université de Hvidovre, au Danemark, où des équipes de quatre personnes travaillent sous la conduite du neuropsychologue
Daniel Chebat mène des travaux au Danemark et au Québec.
À lui seul, Daniel Chebat mène actuellement, au Canada et au Danemark, trois projets de recherche qui feront éventuellement l’objet d’articles scientifiques. Alors que celui auquel M.L. a pris part en est à l’étape de la publication, les deux autres en sont à la phase de l’expérimentation.
Dans le deuxième projet, le doctorant veut explorer l’acuité sensorielle des aveugles sur un parcours complexe comprenant cinq corridors.
Le troisième plongera les sujets dans un jeu vidéo. Ceux-ci seront invités à se déplacer dans un environnement virtuel retransmis sur leurs papilles pendant qu’on examinera leur cerveau à l’aide d’un appareil d’imagerie cérébrale. L’observation du cerveau en action durant l’utilisation de la TDU n’a jamais été tentée.
«La seule limite avec ce dispositif, c’est celle qu’on se donne comme chercheur», mentionne Daniel Chebat, emballé par l’évolution de ses recherches.
«Je veux travailler avec vous!»
La rencontre du jeune homme avec son directeur de thèse s’est faite en 2002, alors que l’étudiant terminait son baccalauréat en psychologie à l’Université Bishop’s, à Lennoxville. «J’avais entendu parler des recherches de Maurice Ptito par les journaux et j’avais envie de me joindre à son équipe. J’étais fasciné par l’extériorisation des sensations. Comment un aveugle pouvait-il sentir une forme par la bouche?»
Lorsqu’il a communiqué avec le neuropsychologue, l’étudiant a senti que la porte était ouverte, mais qu’il devrait faire ses preuves comme chercheur. Conservant une moyenne de 3,7 dans son programme de maitrise, il a gagné le prix de la meilleure présentation à la maitrise à l’École d’optométrie en mars 2005 avec sa recherche sur le collicule supérieur du hamster. Puis, les résultats de cette étude ont été publiés dans le Journal of Comparative Neurology en février 2006. Les preuves étaient faites.
Ses travaux, depuis, lui ont valu plusieurs honneurs. Son résumé de recherche sur l’hippocampe des aveugles de naissance a été sélectionné comme l’un des meilleurs parmi les 14 000 articles soumis à la Society for Neuroscience pour sa revue annuelle en 2006. Il a obtenu des bourses de recherche des Instituts de recherche en santé du Canada et du Réseau Vision.
Travailler sur la plasticité du cerveau est une passion toujours vive. «J’ai l’impression de traiter des sujets vieux de plusieurs siècles, notamment abordés par René Descartes. L’aveugle qui imagine les formes placées devant lui les voit-il? Tout est une question de perception.»
Mathieu-Robert Sauvé
Wednesday, August 29, 2007
Society for Neuroscience 2006 Press Book
Last year in Atlanta, my abstract for the Society for Neuroscience (SfN) was chosen abstracts to be part of their press book release. Every year SfN choses 700 abstracts out of over 14, 000 to release to the media. Here is a copy of that abstract.
Volumetric analysis of the hippocampus in early blind subjects.
Society for Neuroscience 2006
Press Book Summary by Daniel-Robert Chebat and Maurice Ptito
This preliminary study is part of an ongoing research program concerned with the anatomo-functional re-organization of the brain resulting from sensory deprivation at birth. We report here that the hippocampus, a structure involved in learning and memory, is significantly reduced in volume compared to normal seeing controls. This reduction concerns mainly the posterior part of the right hippocampal formation.
This finding is novel and interesting because it supports the hypothesis that the hippocampus is involved in the formation of spatial visual maps of the environment. Since our subjects have been blind from birth, the posterior part of the hippocampus showed atrophy.
Previous studies carried out on blinds have shown that these subjects are not impaired on a spatial competence level and that they maintain the capacity to form spatial maps of the environment when using tactile or proprioceptive and/or auditory cues. The absence of vision however complicates the encoding of spatial maps due to the lack of readily available spatial information. Extensive navigational training in normal subjects induces plastic changes in the hippocampus. For example, London taxi drivers show a larger posterior hippocampus compared to controls!
This study emphasizes therefore the importance of vision in the development of brain structures and the role of the posterior part of the right hippocampus in navigational skills that involve visual cues. We have recently shown that the visual pathways of born blind subjects are largely atrophied (Schneider, Kupers and Ptito, 2006). The striate and extrastriate visual areas have a reduced volume and both afferent and efferent fibers are altered.
The question arises then on how do blind people move around in their environment and what are the cerebral structures involved? It is known that spatial representation of the environment can be encoded through other sensory cues such as somesthesis, touch, audition and proprioception. These maps are not exclusively carried out by the hippocampus itself but rather in tandem with other cortical regions. The anterior insula/ventrolateral prefrontal cortex (AI/VP) and parietal cortex (PC) are most likely candidates. AI/VP is associated with the coding of auditory cues and spontaneous route planning and PC is involved in the planning of movements through immediate space when no visual cues are available.
Although navigation requires visual cues for the formation of spatial maps that involves the right hippocampal formation, early blinds are still able to build novel spatial maps of the environment when using tactile, proprioceptive and/or auditory cues. We hypothetize therefore that these map formations are carried out outside of the hippocampus and probably involve the parietal cortex.
These results have never been published and to our knowledge nobody has previously shown that blindness leads to the atrophy of the right posterior hippocampus, a brain structure known to be involved in the formation of visual maps.
These data were collected from a rather large sample of blind subjects and seeing controls using a double blind protocol with two types of analysis from magnetic resonance images (MRI) : volumetric analysis through segmentation of the hippocampus and voxel-based morphometry (VBM). Both approaches yielded the same results.
What would be interesting to do next is Tensor Diffusion Imaging to highlight the nature of the connections (white matter) between the hippocampus and the other cortical areas and correlate anatomy and behavior through route learning.
Volumetric analysis of the hippocampus in early blind subjects.
Society for Neuroscience 2006
Press Book Summary by Daniel-Robert Chebat and Maurice Ptito
This preliminary study is part of an ongoing research program concerned with the anatomo-functional re-organization of the brain resulting from sensory deprivation at birth. We report here that the hippocampus, a structure involved in learning and memory, is significantly reduced in volume compared to normal seeing controls. This reduction concerns mainly the posterior part of the right hippocampal formation.
This finding is novel and interesting because it supports the hypothesis that the hippocampus is involved in the formation of spatial visual maps of the environment. Since our subjects have been blind from birth, the posterior part of the hippocampus showed atrophy.
Previous studies carried out on blinds have shown that these subjects are not impaired on a spatial competence level and that they maintain the capacity to form spatial maps of the environment when using tactile or proprioceptive and/or auditory cues. The absence of vision however complicates the encoding of spatial maps due to the lack of readily available spatial information. Extensive navigational training in normal subjects induces plastic changes in the hippocampus. For example, London taxi drivers show a larger posterior hippocampus compared to controls!
This study emphasizes therefore the importance of vision in the development of brain structures and the role of the posterior part of the right hippocampus in navigational skills that involve visual cues. We have recently shown that the visual pathways of born blind subjects are largely atrophied (Schneider, Kupers and Ptito, 2006). The striate and extrastriate visual areas have a reduced volume and both afferent and efferent fibers are altered.
The question arises then on how do blind people move around in their environment and what are the cerebral structures involved? It is known that spatial representation of the environment can be encoded through other sensory cues such as somesthesis, touch, audition and proprioception. These maps are not exclusively carried out by the hippocampus itself but rather in tandem with other cortical regions. The anterior insula/ventrolateral prefrontal cortex (AI/VP) and parietal cortex (PC) are most likely candidates. AI/VP is associated with the coding of auditory cues and spontaneous route planning and PC is involved in the planning of movements through immediate space when no visual cues are available.
Although navigation requires visual cues for the formation of spatial maps that involves the right hippocampal formation, early blinds are still able to build novel spatial maps of the environment when using tactile, proprioceptive and/or auditory cues. We hypothetize therefore that these map formations are carried out outside of the hippocampus and probably involve the parietal cortex.
These results have never been published and to our knowledge nobody has previously shown that blindness leads to the atrophy of the right posterior hippocampus, a brain structure known to be involved in the formation of visual maps.
These data were collected from a rather large sample of blind subjects and seeing controls using a double blind protocol with two types of analysis from magnetic resonance images (MRI) : volumetric analysis through segmentation of the hippocampus and voxel-based morphometry (VBM). Both approaches yielded the same results.
What would be interesting to do next is Tensor Diffusion Imaging to highlight the nature of the connections (white matter) between the hippocampus and the other cortical areas and correlate anatomy and behavior through route learning.
Monday, May 14, 2007
Blinde lærer at se med tungen
Dear Readers,
Here is a re-e-print of an article concerning our research that came out recently in a Danish newspaper. I have been in Denmark at the Danish Research Center for MR (DRCMR) in Hvidovre hospital. I am here continuing our research on sensory substitution and navigation in the blind under the direction of my supervisor Dr. Maurice Ptito. The picture below was taken in the hallways of Hvidovre hospital as teh reporter Sophie Nyborg tried the tongue stimulator for the first time. She was able to eprceive movement from the people passing in the hall, and was able to locate and walk towards Dr. Ptito in the hall.
Daniel-Robert Chebat
Blinde lærer at se med tungen
25. april 2007 00:01 Indland Forskning · På gangene inde på Hvidovre Hospital render en lille flok fransk-canadiere rundt og lærer blinde folk at se med tungen. Nyhedsavisen har prøvet teknikken, som samtidig afslører overraskende ting om hjernen for forskerne
Af: Sophie Nyborg (Journalist) Profil Artikler Blog
Popularitet:
32 af 171 journalister
Der er bælgmørkt omkring mig. Jeg tager forsigtigt et skridt fremad. Min tunge kilder. Bare lidt. Det føles nærmest som små champagnebobler på tungen. Idet jeg langsomt drejer hovedet lidt til venstre, begynder det at boble rigtig meget. Jeg fortsætter med at dreje hovedet til venstre og boblerne forsvinder. Jeg vender hovedet til højre igen. Lige midt på min tunge kommer den prikkende følelse tilbage. Jeg går i den retning. Pludselig brager jeg ind i fotografen og udløser et latterbrøl. De sorte briller med det underlige kyklop-kamera i panden ryger hurtigt af.
»Der kan du se, du fandt hende! Er det ikke utroligt?,« siger Maurice Ptito og ser på mig som en far, der lige har overværet sit barn tage det allerførste skridt.
Georg Gearløs
Jeg har netop prøvet at se med tungen – og et kamera. Og selvom min tunge tydeligvis ikke ser særlig godt, så kan den lære det – eller rettere: Min hjerne kan lære den det.
Maurice Ptito er professor i neurobiologi ved Montréal Universitet i Canada, men gæster i øjeblikket Hvidovre Hospital for at udføre sin forskning i, hvordan blinde mennesker kan lære at se med tungen.
Sammen med kollegaen fra Belgien Ron Kupers træner han blinde i at kunne bruge et meget besynderligt stykke elektronik, der mere får tankerne til at falde på Georg Gearløs fra et Anders And-blad end på fremmelig hjerneforskning.
Den blinde tager en lille bøjelig plade – hvorpå der sidder en masse små elektroder – i munden. Den er forbundet til et kamera, der sidder på panden, og omdanner levende billeder til elektriske impulser på tungen. Jo mørkere nuancer, jo mere intensitet i signalet.
»Det lyder vildt, og det er heller ikke sådan, at de blinde kommer til at se, som vi ser med vores øjne. Men de bliver simpelthen så glade, du vil ikke tro på det. De kan lære at læse bogstaver, de kan lære at 'se' forskel på former, bevægelser, at kende forskel på lys og skygge i omgivelserne og opfatte, at der er mennesker, huse, trapper, biler eller mennesker foran dem. Jo længere væk, jo svagere signal. Bare det at opfatte bevægelse er et mirakel for dem, siger de. Og at de ikke er begrænset af blindestokkens eller armens længde,« forklarer Ptito.
Forskerne ved dog ikke præcist, hvordan hjernen på denne måde lærer at omdanne føleimpulserne fra tungen til en rumopfattelse.
Danmark i front
Og det er lige netop derfor, at Maurice Ptito og to af hans ph.d.-studerende lige nu arbejder på Hvidovre Hospitals MR-scanningsafdeling. For vi har nemlig i omverdenens øjne noget af det bedste hjernescanningsudstyr og god ekspertise i at bruge det.
Dermed er Danmark ret godt med i noget af det, som hjerneforskningen verden rundt fokuserer meget på i øjeblikket – nemlig at undersøge, hvor 'omprogrammerbar' vores hjerne er.
I de senere år er forskerne med hjernescanninger blevet i stand til at se, hvilken del af hjernen, der er aktiv, når vi udfører bestemte handlinger, såsom at læse, tænke på vores kæreste eller spille med en bold. Og forskerne kan altså nu også se, at hjernen tilpasser sig meget mere efter, hvordan vi bruger den, end hvad man hidtil har troet. Vi kan med andre ord danne vores egne evner og træne hjernen, lidt som man træner sin krop.
»Det mest utrolige er, at vi kan se, at hjernen efter nogle ugers træning ændrer sig rent fysisk, den ændrer struktur. Folk, der aldrig har kunnet se, har også et manglende eller underudviklet synscenter, Men vi kan se, at flere og flere synsnerveceller bliver inddraget fra det omgivende hjernevæv til det visuelle område, efterhånden som de blinde træner med tungen. De får simpelthen et udviklet synscenter,« forklarer Ptito med en fransk accent, der er står lige så meget i kontrast til de kliniske og flade kittel-omgivelser i Hvidovre som hans sorte, figursyede jakkesæt og sorte, spidse sko.
Spiller computer
I øjeblikket har Ptito syv blinde forsøgspersoner, hvis hjerner han scanner, mens de bruger det såkaldte 'Tongue Display Unit' (TDU). På den måde kan han se, hvordan det præcis er, at hjernen lærer at se med tungen.
Men i stedet for at have et kamera, der laver bobler på tungen – forsøgspersonerne ligger jo stille i en scanner – så er det et computerprogram, der skaber enten en bevægelse eller en figur, som personen skal 'se' og genkende.
Lige nu træner han blinde i at kunne læse bogstaver på tungen. En af øvelserne handler om at se, om folk kan lære at kende forskel på, om et T vender på hovedet eller til siden.
En af hjerneforskernes 'forsøgskaniner' er Ole Brun Jensen. Han blev blind umiddelbart efter fødslen, fordi han blev født to en halv måned for tidligt og måtte have ren ilt i kuvøsen.
»I løbet af et splitsekund ved jeg, om det T, som står på computerskærmen, vender den ene eller den anden vej. Det var en underlig oplevelse, da der først var hul igennem. I starten var det bare en kildren på tungen, og jeg kunne overhovedet ikke kende ting fra hinanden. Da jeg først havde lært det efter et par timer, så blev det lysende klart for mig, hvad jeg blev præsenteret for, nærmest inden jeg føler noget på tungen. Men det er svært at forklare hvordan,« siger Ole Brun Jensen.
Computerspil på tungen
Ptito har også for nyligt udviklet et computerspil, som de blinde skal spille, mens de er i skanneren. Computerspillet går ud på, at den blinde skal bevæge sig rundt i en labyrint med et joystick i hånden, og det bliver 'spillet' på tungen.
»Vi kan se, at de efter noget tid udvikler aktivitet i det område af hjernen, som er aktivt, når mennesker ser med øjnene, men der kommer også aktivitet i det område, som har med stedsans at gøre – når mennesker, der kan se, danner et slags geografisk kort inde i hovedet. Så de danner sig en form for visuel fornemmelse af rummet omkring sig ud fra følesansen, selvom de aldrig har set verden,« siger Ptito.
I princippet kunne man også bruge et andet sted på kroppen »som indgang til hjernens synscenter«, men tungen er oplagt, dels fordi den er meget følsom, og dels fordi de elektriske impulser fungerer bedst på en fugtig overflade.
»Tungen er jo også det første, som spædbørn bruger til at udforske verden med. I stedet for at se på det propper de alt i munden,« forklarer Ptito.
I Canada har forskerne bygget deciderede forhindringsbaner. Udstyret med elektroder på tungen og et kamera i panden testede de, hvor godt de blinde kunne orientere sig uden stok eller hund. Det var tydeligt at se, at de blinde gik uden om ting, de ellers ville være stødt ind i.
Men det er ikke nogen mirakelkur, påpeger Ptito, og det giver Ole Brun Jensen ham indtil videre ret i.
»Jeg kan jo stadig ikke se som andre. Jeg aner stadig ikke, hvad farver er. Men jeg håber, det bliver nemmere at læse fra computeren. Det ville også være fantastisk at kunne bevæge sig rundt lidt friere. Og måske at komme til at kunne genkende et ansigt,« siger han.
Så en flamme
Hvor stor nytte man som blind kan få af TDU'en, er meget individuelt påpeger Ptito.
En af de blindfødte forsøgspersoner, der tidligere har prøvet TDU'en, beskriver for eksempel over for det videnskabelige nyhedsmagasin Science News, at hun altid havde troet, at stearinflammer var kæmpestore ildkugler. Sådan kunne hun nemlig normalt føle varmen brede sig ud fra lyset. Da hun første gang 'så' et stearinlys med tungen, blev hun chokeret over, hvor lille flammen var, og hvor meget den dansede.
Så TDU'en kan sagtens give blinde en helt ny virkelighedsopfattelse. Og perspektiverne er vidtrækkene, mener den fransk-canadiske professor. Men han kan endnu ikke sige noget om, hvornår TDU'en bliver tilgængelig for almindelige mennesker.
»Måske om fem til syv år vil blinde kunne bruge den. Men det, vi gør lige nu, er jo også at finde ud af så meget som muligt om, hvordan hjernen fungerer med vores sanser. Jo mere viden vi får om hjernen, jo mere kan man udvikle teknikken – eller blive i stand til at udvikle endnu smartere teknikker. Det næste bliver at give kameraet en zoom-funktion,« siger han.
Han mener, perspektivet er, at kameraet muligvis kan blive implanteret i øjnene, mens tungetingen kan installeres i et lille, diskret mundstykke, som brugeren aktiverer ved at trykke tungen op i ganen. I den nærmeste fremtid vil det mest umiddelbare dog være at gøre det nemmere for blinde at læse, fordi man vil kunne få sendt elektronisk eller digital information direkte ind i tungen fra computeren og nettet, mener han.
Af: Sophie Nyborg (Journalist) Profil Artikler Blog
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Der er bælgmørkt omkring mig. Jeg tager forsigtigt et skridt fremad. Min tunge kilder. Bare lidt. Det føles nærmest som små champagnebobler på tungen. Idet jeg langsomt drejer hovedet lidt til venstre, begynder det at boble rigtig meget. Jeg fortsætter med at dreje hovedet til venstre og boblerne forsvinder. Jeg vender hovedet til højre igen. Lige midt på min tunge kommer den prikkende følelse tilbage. Jeg går i den retning. Pludselig brager jeg ind i fotografen og udløser et latterbrøl. De sorte briller med det underlige kyklop-kamera i panden ryger hurtigt af.
»Der kan du se, du fandt hende! Er det ikke utroligt?,« siger Maurice Ptito og ser på mig som en far, der lige har overværet sit barn tage det allerførste skridt.
Georg Gearløs
Jeg har netop prøvet at se med tungen – og et kamera. Og selvom min tunge tydeligvis ikke ser særlig godt, så kan den lære det – eller rettere: Min hjerne kan lære den det.
Maurice Ptito er professor i neurobiologi ved Montréal Universitet i Canada, men gæster i øjeblikket Hvidovre Hospital for at udføre sin forskning i, hvordan blinde mennesker kan lære at se med tungen.
Sammen med kollegaen fra Belgien Ron Kupers træner han blinde i at kunne bruge et meget besynderligt stykke elektronik, der mere får tankerne til at falde på Georg Gearløs fra et Anders And-blad end på fremmelig hjerneforskning.
Den blinde tager en lille bøjelig plade – hvorpå der sidder en masse små elektroder – i munden. Den er forbundet til et kamera, der sidder på panden, og omdanner levende billeder til elektriske impulser på tungen. Jo mørkere nuancer, jo mere intensitet i signalet.
»Det lyder vildt, og det er heller ikke sådan, at de blinde kommer til at se, som vi ser med vores øjne. Men de bliver simpelthen så glade, du vil ikke tro på det. De kan lære at læse bogstaver, de kan lære at 'se' forskel på former, bevægelser, at kende forskel på lys og skygge i omgivelserne og opfatte, at der er mennesker, huse, trapper, biler eller mennesker foran dem. Jo længere væk, jo svagere signal. Bare det at opfatte bevægelse er et mirakel for dem, siger de. Og at de ikke er begrænset af blindestokkens eller armens længde,« forklarer Ptito.
Forskerne ved dog ikke præcist, hvordan hjernen på denne måde lærer at omdanne føleimpulserne fra tungen til en rumopfattelse.
Danmark i front
Og det er lige netop derfor, at Maurice Ptito og to af hans ph.d.-studerende lige nu arbejder på Hvidovre Hospitals MR-scanningsafdeling. For vi har nemlig i omverdenens øjne noget af det bedste hjernescanningsudstyr og god ekspertise i at bruge det.
Dermed er Danmark ret godt med i noget af det, som hjerneforskningen verden rundt fokuserer meget på i øjeblikket – nemlig at undersøge, hvor 'omprogrammerbar' vores hjerne er.
I de senere år er forskerne med hjernescanninger blevet i stand til at se, hvilken del af hjernen, der er aktiv, når vi udfører bestemte handlinger, såsom at læse, tænke på vores kæreste eller spille med en bold. Og forskerne kan altså nu også se, at hjernen tilpasser sig meget mere efter, hvordan vi bruger den, end hvad man hidtil har troet. Vi kan med andre ord danne vores egne evner og træne hjernen, lidt som man træner sin krop.
»Det mest utrolige er, at vi kan se, at hjernen efter nogle ugers træning ændrer sig rent fysisk, den ændrer struktur. Folk, der aldrig har kunnet se, har også et manglende eller underudviklet synscenter, Men vi kan se, at flere og flere synsnerveceller bliver inddraget fra det omgivende hjernevæv til det visuelle område, efterhånden som de blinde træner med tungen. De får simpelthen et udviklet synscenter,« forklarer Ptito med en fransk accent, der er står lige så meget i kontrast til de kliniske og flade kittel-omgivelser i Hvidovre som hans sorte, figursyede jakkesæt og sorte, spidse sko.
Spiller computer
I øjeblikket har Ptito syv blinde forsøgspersoner, hvis hjerner han scanner, mens de bruger det såkaldte 'Tongue Display Unit' (TDU). På den måde kan han se, hvordan det præcis er, at hjernen lærer at se med tungen.
Men i stedet for at have et kamera, der laver bobler på tungen – forsøgspersonerne ligger jo stille i en scanner – så er det et computerprogram, der skaber enten en bevægelse eller en figur, som personen skal 'se' og genkende.
Lige nu træner han blinde i at kunne læse bogstaver på tungen. En af øvelserne handler om at se, om folk kan lære at kende forskel på, om et T vender på hovedet eller til siden.
En af hjerneforskernes 'forsøgskaniner' er Ole Brun Jensen. Han blev blind umiddelbart efter fødslen, fordi han blev født to en halv måned for tidligt og måtte have ren ilt i kuvøsen.
»I løbet af et splitsekund ved jeg, om det T, som står på computerskærmen, vender den ene eller den anden vej. Det var en underlig oplevelse, da der først var hul igennem. I starten var det bare en kildren på tungen, og jeg kunne overhovedet ikke kende ting fra hinanden. Da jeg først havde lært det efter et par timer, så blev det lysende klart for mig, hvad jeg blev præsenteret for, nærmest inden jeg føler noget på tungen. Men det er svært at forklare hvordan,« siger Ole Brun Jensen.
Computerspil på tungen
Ptito har også for nyligt udviklet et computerspil, som de blinde skal spille, mens de er i skanneren. Computerspillet går ud på, at den blinde skal bevæge sig rundt i en labyrint med et joystick i hånden, og det bliver 'spillet' på tungen.
»Vi kan se, at de efter noget tid udvikler aktivitet i det område af hjernen, som er aktivt, når mennesker ser med øjnene, men der kommer også aktivitet i det område, som har med stedsans at gøre – når mennesker, der kan se, danner et slags geografisk kort inde i hovedet. Så de danner sig en form for visuel fornemmelse af rummet omkring sig ud fra følesansen, selvom de aldrig har set verden,« siger Ptito.
I princippet kunne man også bruge et andet sted på kroppen »som indgang til hjernens synscenter«, men tungen er oplagt, dels fordi den er meget følsom, og dels fordi de elektriske impulser fungerer bedst på en fugtig overflade.
»Tungen er jo også det første, som spædbørn bruger til at udforske verden med. I stedet for at se på det propper de alt i munden,« forklarer Ptito.
I Canada har forskerne bygget deciderede forhindringsbaner. Udstyret med elektroder på tungen og et kamera i panden testede de, hvor godt de blinde kunne orientere sig uden stok eller hund. Det var tydeligt at se, at de blinde gik uden om ting, de ellers ville være stødt ind i.
Men det er ikke nogen mirakelkur, påpeger Ptito, og det giver Ole Brun Jensen ham indtil videre ret i.
»Jeg kan jo stadig ikke se som andre. Jeg aner stadig ikke, hvad farver er. Men jeg håber, det bliver nemmere at læse fra computeren. Det ville også være fantastisk at kunne bevæge sig rundt lidt friere. Og måske at komme til at kunne genkende et ansigt,« siger han.
Så en flamme
Hvor stor nytte man som blind kan få af TDU'en, er meget individuelt påpeger Ptito.
En af de blindfødte forsøgspersoner, der tidligere har prøvet TDU'en, beskriver for eksempel over for det videnskabelige nyhedsmagasin Science News, at hun altid havde troet, at stearinflammer var kæmpestore ildkugler. Sådan kunne hun nemlig normalt føle varmen brede sig ud fra lyset. Da hun første gang 'så' et stearinlys med tungen, blev hun chokeret over, hvor lille flammen var, og hvor meget den dansede.
Så TDU'en kan sagtens give blinde en helt ny virkelighedsopfattelse. Og perspektiverne er vidtrækkene, mener den fransk-canadiske professor. Men han kan endnu ikke sige noget om, hvornår TDU'en bliver tilgængelig for almindelige mennesker.
»Måske om fem til syv år vil blinde kunne bruge den. Men det, vi gør lige nu, er jo også at finde ud af så meget som muligt om, hvordan hjernen fungerer med vores sanser. Jo mere viden vi får om hjernen, jo mere kan man udvikle teknikken – eller blive i stand til at udvikle endnu smartere teknikker. Det næste bliver at give kameraet en zoom-funktion,« siger han.
Han mener, perspektivet er, at kameraet muligvis kan blive implanteret i øjnene, mens tungetingen kan installeres i et lille, diskret mundstykke, som brugeren aktiverer ved at trykke tungen op i ganen. I den nærmeste fremtid vil det mest umiddelbare dog være at gøre det nemmere for blinde at læse, fordi man vil kunne få sendt elektronisk eller digital information direkte ind i tungen fra computeren og nettet, mener han.
Monday, April 02, 2007
Society for Neuroscience Pressbook release
Félicitations (encore!) au Dr. Maurice Ptito
Les travaux du laboratoire du Dr. Maurice Ptito furent inclus dans le livret dédié aux médias lors de la dernière réunion annuelle de la Society for Neuroscience.
Chebat, D.-R., Chen, J.-K., Ptito, A., Schneider, F., Kupers, R. Ptito, M., (2006). Volumetric analysis of the hippocampus in early blind subjects, prog. #366.30.
De plus, les travaux du laboratoire ont été publiés dans les Proceedings of the National Academy of Science. Cette article s'est mérité une recommandation comme nouvelle découverte par le faculty of 1000 Biology (Sep. 2006).Kupers, R., Fumal, A., de Noordhout, A., Gjedde, J., Schoenen, A., Ptito, M. (2006). Transcranial magnetic stimulation of the visual cortex induces somatotopically organized qualia in blind subjects. PNAS, 103, 13256-13260.
Les travaux du laboratoire du Dr. Maurice Ptito furent inclus dans le livret dédié aux médias lors de la dernière réunion annuelle de la Society for Neuroscience.
Chebat, D.-R., Chen, J.-K., Ptito, A., Schneider, F., Kupers, R. Ptito, M., (2006). Volumetric analysis of the hippocampus in early blind subjects, prog. #366.30.
De plus, les travaux du laboratoire ont été publiés dans les Proceedings of the National Academy of Science. Cette article s'est mérité une recommandation comme nouvelle découverte par le faculty of 1000 Biology (Sep. 2006).Kupers, R., Fumal, A., de Noordhout, A., Gjedde, J., Schoenen, A., Ptito, M. (2006). Transcranial magnetic stimulation of the visual cortex induces somatotopically organized qualia in blind subjects. PNAS, 103, 13256-13260.
Félicitations au Dr. Maurice Ptito!
Le directeur de la fondation (gauche) présente le prix d’excellence Henry and Karla Hensen
Le Dr. Maurice Ptito (droite), en compagnie du représentatnt de l'Université de Montréal le Dr. Christian Casanova (gauche) lors de la remise du prix.
(texte apparu dans le bulletin de nouvelles du Réseau Vision : http://www.reseauvision.ca/vision-FR/news-annonces-fr.html#Ptito_2007)
Félicitations au Dr. Maurice Ptito!
Le cabinet d’avocat Jon Palle Buhl, gestionnaire du prix d’excellence Henry and Karla Hensen, a annoncé que le professeur Maurice Ptito était le lauréat du prix pour l’année 2007, qui s’accompagne de 500 000DKK (100 000$ CAD). Cet honneur est généralement attribué à un scientifique œuvrant dans des domaines tels que la recherche sur le cœur ou la sclérose en plaque. Étant donné le caractère novateur de sa recherche sur la plasticité intermodale et l’impact de ses travaux auprès des non-voyants, le comité a recommandé le Dr. Ptito comme récipiendaire du prix d’excellence Henry and Karla Hensen. Ce dernier fût remis au professeur Ptito durant une cérémonie le 2 Mars 2007 au Musée Frilands à Lyngby. Félicitations à Maurice!
Le cabinet d’avocat Jon Palle Buhl, gestionnaire du prix d’excellence Henry and Karla Hensen, a annoncé que le professeur Maurice Ptito était le lauréat du prix pour l’année 2007, qui s’accompagne de 500 000DKK (100 000$ CAD). Cet honneur est généralement attribué à un scientifique œuvrant dans des domaines tels que la recherche sur le cœur ou la sclérose en plaque. Étant donné le caractère novateur de sa recherche sur la plasticité intermodale et l’impact de ses travaux auprès des non-voyants, le comité a recommandé le Dr. Ptito comme récipiendaire du prix d’excellence Henry and Karla Hensen. Ce dernier fût remis au professeur Ptito durant une cérémonie le 2 Mars 2007 au Musée Frilands à Lyngby. Félicitations à Maurice!
Tuesday, February 06, 2007
'Sight' that tingles NATIONAL POST;
Dear Blog-readers,
Here is an article that was published today in the canadian newspaper National Post. It describes certain aspects of our research. Allison Hanes was a pleasure to work with and was easy to talk to and i think she did a really great job explaining our research. She got this little detail wrong however, the information from the tongue usually goes to the somatosensory cortex in sighted controls, not the motor cortex. I sent them this video of one of my subjects (Mr. L., some of you may recognize him from Decouverte on Radio-Canada; see: http://www.radio-canada.ca/actualite/v2/decouverte/niveau2_8722.shtml). Take a look at this video on the National Post website, this very short clip shows Mr. L negociating his way through the obstacle course where we tested subjects this summer:
http://video.canada.com/VideoContent.aspx?&fl=&popup=1
send me your comments on my blog!
I hope to hear from you soon,
Daniel
'Sight' that tingles
Canadian researchers part of team testing revolutionary technology for the blind: Nationalpost.com
Allison Hanes, National PostPublished: Tuesday, February 06, 2007
Last summer Mike Ciarciello went to a Montreal laboratory, donned a pair of goggles mounted with a camera and stuck a strange device the size of a quarter in his mouth.
By constantly moving his head from side to side to scan the room and pressing his tongue against a square of 100 tiny electrodes, the 36-year-old, who has been blind since birth, was able to "see" for the first time.
For a few short hours, Mr. Ciarciello stepped out of his arm's-length universe of shadows and light to make out a black triangle projected on to a white wall, navigate an obstacle course, even perceive that a person was walking in front of him.
The technology is the brainchild of U.S. doctor and scientist Paul Bach-y-Rita, a pioneer in a field called substitution theory, who believed people actually see with their brains, not their eyes.
Using the technology patented by Dr. Bach-y-Rita's Wisconsin- based company requires considerable training before the test subjects can make sense of all the tiny pops and buzzes on the tongue.
For starters, blind people are commonly taught to stay as still and straight as possible when they use a cane or a guide dog to get around.
"What I tell them is the opposite," Mr. Chebat explained. "Since the subject is wearing this camera on his forehead, as he moves this image changes. He learns to recognize that, as with eyesight ... when we move our eyes or we move our heads, the images changes."
It is often the first time these test subjects learn how to process information on shifting perspective and distance: "One of the obstacles we had was a bar blocking the entire width of the hallway ... And so if you couldn't judge distances very well, there's no way you could have stepped over it," Mr. Chebat said. "I say, 'Look at your feet. Do you see your feet? They're on the tip of your tongue if look down, if you're wearing black shoes. Then if you look up, do you see that bar? Now how long did it take you to make that movement? OK, so how far do you think that bar is from you?' So through trial and error, they learn to judge the distances and how the head movements translate to distances."
After relying his whole life on his hands and fingers to navigate the world, Mr. Ciarciello said using the technology took some getting used to.
The biggest challenge, he said, was rewiring his reactions to make use of new information being supplied to his brain.
"I realized: 'Don't wait until you bump into an object to go around it -- go around it before you bump in to it!' "he said. "When you're not used to seeing things from a distance, it's a whole new ball game."
Blind people's worlds are essentially limited to what is at arm's-length. They take in information -- the placement of objects, the shape of people's faces, writing in braille -- using their hands, or a white cane. The tongue devices have the power to change all that -- expanding their surroundings from the car parked a block away to the mountain on the horizon.
"It's hard to describe to people who take it for granted that they can see," Mr. Ciarciello said. "This opens up a whole other door."
Visit our homepage to watch an exclusive video showing how this technology is helping the blind to "see."
© National Post 2007
Here is an article that was published today in the canadian newspaper National Post. It describes certain aspects of our research. Allison Hanes was a pleasure to work with and was easy to talk to and i think she did a really great job explaining our research. She got this little detail wrong however, the information from the tongue usually goes to the somatosensory cortex in sighted controls, not the motor cortex. I sent them this video of one of my subjects (Mr. L., some of you may recognize him from Decouverte on Radio-Canada; see: http://www.radio-canada.ca/actualite/v2/decouverte/niveau2_8722.shtml). Take a look at this video on the National Post website, this very short clip shows Mr. L negociating his way through the obstacle course where we tested subjects this summer:
http://video.canada.com/VideoContent.aspx?&fl=&popup=1
send me your comments on my blog!
I hope to hear from you soon,
Daniel
'Sight' that tingles
Canadian researchers part of team testing revolutionary technology for the blind: Nationalpost.com
Allison Hanes, National PostPublished: Tuesday, February 06, 2007
Last summer Mike Ciarciello went to a Montreal laboratory, donned a pair of goggles mounted with a camera and stuck a strange device the size of a quarter in his mouth.
By constantly moving his head from side to side to scan the room and pressing his tongue against a square of 100 tiny electrodes, the 36-year-old, who has been blind since birth, was able to "see" for the first time.
For a few short hours, Mr. Ciarciello stepped out of his arm's-length universe of shadows and light to make out a black triangle projected on to a white wall, navigate an obstacle course, even perceive that a person was walking in front of him.
"The guy came in on my left then moved to my right. I was actually able to see that. I was like, 'Hey get out of my way!' "he said with a laugh.
It was an indescribable experience for the teacher and musician who normally feels his way through life with his hands and a cane.
The blind could be able to see with their tongues within a decade due to the latest advances in technology and neuropsychology.
An electrical-impulse-emitting device being developed by researchers in Canada, Denmark and the United States is already allowing those like Mr. Ciarciello to detect movement and sense objects at a distance. One day it may allow them to perceive faces and colours -- even read text.
Maurice Ptito, a Universite de Montreal neuropsychologist testing the revolutionary technology on people like Mr. Ciarciello, hopes the invention will do for the blind what the hearing aid did for the deaf.
"For blind people it's so important, because it means they could do it without a dog or a cane," he said in an interview from Copenhagen, where he is on a year-long sabbatical. "They could feel motion, things coming to them, or things moving from left to right. It's quite fantastic actually."
The devices, called tongue display units, do not bestow the gift of sight. What they can do is help the blind experience the world around them in a much more profound way than has previously been possible.
"You are not going to recover vision, but we can substitute something else for it," he said. "If you don't have eyes, you can't see ... But what's nice is that they can feel the world through their tongues, and they can feel it at a distance. For them, it's something that is really incredible."
In laboratories in Montreal and Copenhagen, test subjects born without sight have been making remarkable progress in sensing their way. Tiny cameras perched on eyeglasses or helmets translate images into tingling sensations, not unlike morse code.
Prof. Ptito describes the feeling as comparable to champagne bubbles.
The tongue can be trained to glean information from the electrical impulses it transmits to the brain, distinguishing the difference between a triangle and a square for example, or even the letter T.
Because the tongue is a wet milieu -- and one of the most sensitive organs in the human body --it is the perfect conduit.
Subjects are being tested to perceive black geometric shapes on a white background. Black is indicated by a tingling of maximum intensity while white is conveyed by no sensation at all.They have also been taught a handful of letters from the alphabet allowing them to spell out short words.
Those testing the tongue units have not yet ventured beyond the confines of a lab, but Prof. Ptito said they will soon begin trials outdoors.
It was an indescribable experience for the teacher and musician who normally feels his way through life with his hands and a cane.
The blind could be able to see with their tongues within a decade due to the latest advances in technology and neuropsychology.
An electrical-impulse-emitting device being developed by researchers in Canada, Denmark and the United States is already allowing those like Mr. Ciarciello to detect movement and sense objects at a distance. One day it may allow them to perceive faces and colours -- even read text.
Maurice Ptito, a Universite de Montreal neuropsychologist testing the revolutionary technology on people like Mr. Ciarciello, hopes the invention will do for the blind what the hearing aid did for the deaf.
"For blind people it's so important, because it means they could do it without a dog or a cane," he said in an interview from Copenhagen, where he is on a year-long sabbatical. "They could feel motion, things coming to them, or things moving from left to right. It's quite fantastic actually."
The devices, called tongue display units, do not bestow the gift of sight. What they can do is help the blind experience the world around them in a much more profound way than has previously been possible.
"You are not going to recover vision, but we can substitute something else for it," he said. "If you don't have eyes, you can't see ... But what's nice is that they can feel the world through their tongues, and they can feel it at a distance. For them, it's something that is really incredible."
In laboratories in Montreal and Copenhagen, test subjects born without sight have been making remarkable progress in sensing their way. Tiny cameras perched on eyeglasses or helmets translate images into tingling sensations, not unlike morse code.
Prof. Ptito describes the feeling as comparable to champagne bubbles.
The tongue can be trained to glean information from the electrical impulses it transmits to the brain, distinguishing the difference between a triangle and a square for example, or even the letter T.
Because the tongue is a wet milieu -- and one of the most sensitive organs in the human body --it is the perfect conduit.
Subjects are being tested to perceive black geometric shapes on a white background. Black is indicated by a tingling of maximum intensity while white is conveyed by no sensation at all.They have also been taught a handful of letters from the alphabet allowing them to spell out short words.
Those testing the tongue units have not yet ventured beyond the confines of a lab, but Prof. Ptito said they will soon begin trials outdoors.
The technology is the brainchild of U.S. doctor and scientist Paul Bach-y-Rita, a pioneer in a field called substitution theory, who believed people actually see with their brains, not their eyes.
Daniel-Robert Chebat, the Ph D student who conducted tests on 36 blind subjects in the Montreal lab, said one of the most exciting findings is that the electrical impulses transmitted by the tongue to the brain activate the visual cortex: "We know that this type of information normally should go to the motor cortex and yet it's in the visual cortex ... The question is, are we unmasking old connections that are already there or are we rather creating new ones in the brain?"
Using the technology patented by Dr. Bach-y-Rita's Wisconsin- based company requires considerable training before the test subjects can make sense of all the tiny pops and buzzes on the tongue.
For starters, blind people are commonly taught to stay as still and straight as possible when they use a cane or a guide dog to get around.
"What I tell them is the opposite," Mr. Chebat explained. "Since the subject is wearing this camera on his forehead, as he moves this image changes. He learns to recognize that, as with eyesight ... when we move our eyes or we move our heads, the images changes."
It is often the first time these test subjects learn how to process information on shifting perspective and distance: "One of the obstacles we had was a bar blocking the entire width of the hallway ... And so if you couldn't judge distances very well, there's no way you could have stepped over it," Mr. Chebat said. "I say, 'Look at your feet. Do you see your feet? They're on the tip of your tongue if look down, if you're wearing black shoes. Then if you look up, do you see that bar? Now how long did it take you to make that movement? OK, so how far do you think that bar is from you?' So through trial and error, they learn to judge the distances and how the head movements translate to distances."
After relying his whole life on his hands and fingers to navigate the world, Mr. Ciarciello said using the technology took some getting used to.
The biggest challenge, he said, was rewiring his reactions to make use of new information being supplied to his brain.
"I realized: 'Don't wait until you bump into an object to go around it -- go around it before you bump in to it!' "he said. "When you're not used to seeing things from a distance, it's a whole new ball game."
Blind people's worlds are essentially limited to what is at arm's-length. They take in information -- the placement of objects, the shape of people's faces, writing in braille -- using their hands, or a white cane. The tongue devices have the power to change all that -- expanding their surroundings from the car parked a block away to the mountain on the horizon.
"It's hard to describe to people who take it for granted that they can see," Mr. Ciarciello said. "This opens up a whole other door."
Visit our homepage to watch an exclusive video showing how this technology is helping the blind to "see."
© National Post 2007
SEEING WITH TONGUES: New technology to help the blind...Visual data is transmitted from a tiny camera on the forehead to a device on the tongue as electrical impulses. The impulses activate the visual cortex of the brain, allowing the user to sense the world around them. For the first time, blind people will be able to sense objects in the distance and even movement. Photograph by : Kagan McLeod, National Post
Wednesday, January 17, 2007
FORUM volume 41, 15 Janvier
C’est la gloire pour Maurice Ptito
Il expérimente un dispositif lingual permettant aux aveugles de «voir» avec leur langue.
Le réseau télévisé d’information continue britannique BBC World a diffusé, le 11 décembre dernier, un reportage sur une recherche du neuropsychologue Maurice Ptito, professeur à l’École d’optométrie, qui expérimente un dispositif lingual permettant aux aveugles de «voir» avec leur langue. Après la diffusion de ce reportage, les chaines ABC puis Eurovision ont également fait écho aux travaux de cet expert du développement du système visuel. «C’est, à ma connaissance, la recherche qui a suscité, sur le plan médiatique, le plus de réactions internationales au cours des 10 dernières années», mentionne Sophie Langlois, directrice des relations médias pour l’Université.C’est à la suite de la parution d’un premier article en juin 2004 dans Forum express, un bulletin bisannuel bilingue sur la recherche à l’UdeM envoyé dans la plupart des salles de presse d’Amérique et d’Europe, que l’engouement s’est manifesté. Des publications comme le New York Times (24 novembre 2004) et Der Spiegel (3 juin 2004) ainsi que d’innombrables sites Web (Healthnews, MedlinePlus, Science Daily, News-Medical.net, etc.) ont fait état des travaux du chercheur québécois, sans parler des médias canadiens (Le Devoir, La Presse, Radio-Canada, Canal Z). La revue de presse, partielle, des retombées de ce projet de recherche fait à elle seule plus de 100 pages.
Joint au Danemark, où il poursuit ses travaux sur le dispositif lingual à l’Université d’Århus, Maurice Ptito se montre agréablement surpris, bien qu’étonné, par cet enthousiasme. «Nous avons reçu une quinzaine de demandes d’entrevues au cours des derniers jours. Des recherchistes de l’émission The Oprah Winfrey Show ont même communiqué avec nous après des reportages qu’ont diffusés BBC World et ABC, indique-t-il, amusé. Rien n’est confirmé pour l’heure, mais c’est déjà quelque chose.»
L’émission hebdomadaire de la célèbre animatrice américaine, qui est le talk-show le plus populaire de la planète, a des cotes d’écoute de l’ordre de 30 millions de téléspectateurs dans 109 pays.
Labyrinthes pour aveugles
À l’époque où Forum express avait rencontré le professeur, les sujets de recherche devaient tenter de distinguer la lettre T dans différentes positions à l’aide de la Tongue Display Unit (TDU), mise au point à l’origine par le professeur Paul Bach-y Rita, de l’Université du Wisconsin. Depuis, l’appareil s’est perfectionné au point de permettre aux non-voyants de s’orienter dans un environnement contrôlé.
Grâce à d’importantes subventions qui lui ont été accordées (il est notamment devenu titulaire de la Chaire Colonel-Harland-Sanders en sciences de la vision de l’UdeM, dotée d’un capital de 1,2 M$), Maurice Ptito a pu aménager de vastes locaux de recherche. Des labyrinthes ont été construits à l’École d’optométrie et à l’Université d’Århus, où des équipes de quatre personnes, sous la direction du neuropsychologue, mènent des expériences encore plus poussées sur la TDU. Les sujets de recherche, qui souffrent de déficience visuelle et qui sont au nombre de 22 à Montréal et de 20 au Danemark, participent aux succès de l’expérience.
«La langue ne remplacera jamais l’œil, bien entendu, signale le professeur Ptito. Mais, chez des aveugles de naissance, le cortex cérébral dévolu à la vision se réactive sous l’effet de ce dispositif. L’activité électrique, enregistrée par tomodensitomètre, est très claire sur ce point.»
Pour le chercheur, cette visibilité internationale demeure anecdotique. La TDU permet d’abord et avant tout de réaliser des percées scientifiques majeures. D’ailleurs, son équipe a publié en 2005 et 2006 des articles dans des revues prestigieuses comme Brain et PNAS.
Mathieu-Robert Sauvé
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