Dyslexia: a different perceptual strategy, and how to learn a new strategy for reading. Gadi Geiger Center for Biological and Computational Learning Brain and Cognitive Sciences McGovern Institute for Brain Research Massachusetts Institute of Technology Cambridge MA

Developmental dyslexia: some references Orton: Modern dyslexia Gillingham, A and Stillman, B, (1970), ‘Remedial training for.. General developmental (lag) issues: Frostig, M. and Horne, D. (1964) The Frostig Program.. But Lewis, J.N. (1968), J. of Learning Disabilities 1 (11): Brain anatomy, ectopias and auto-immune/hormonal issues: Galaburda, A.M et Al. (1985), Ann. Neurol 18: Language deficit and phoneme awareness: Liberman, I.Y. (1971), Bull. Orton Soc. 21: Velutino, F. R. (1987) ‘Dyslexia’ Sci. Am., 256(3), Auditory deficits: Tallal, P. and Katz, W. (1989) in Brain and Reading Wright, B.A. et al. (1997), Nature 387:

Visual evidence: Misalignment of the two eyes: Stein, J.F. and Fowler, M.S. (1981), TINS 4: Transient and sustain sub-systems hypothesis: Lovegrove, W.J. et al.(1986), Cog. Neuropsychol 3: The magnocellular pathway deficit hypothesis: Livingstone, et al. (1991), Proc. Natl. Acad. Sci. USA 88: Visual stability and the generalized magnocellular hypothesis: Stein, J. and Walsh, V. (1997), TINS 20: But: E.g: Amitay, S. et al. (2002), Brain, 125(10): Tactile evidence: Grant, A.C. et al. (1999), Neuropsychologia 37, Attention: Facoetti, A. et al. (2003). Cog. Brain Res. 16,

Epidemiology and some numbers: Rutter,M and Yule. W., (1975). Psychiatry, Shaywitz, S.E. et al..(1992), (distribution) N. Engl. J. Med. 326, Shaywitz, S.E. et al. (1990) (boys girls) JAMA 264, “National” frequency of dyslexia: Lindgren, S.D. et al. (1985),’ Child Development 56, Definitions of dyslexia: The World Federation of Neurology: “A disorder manifested by difficulty in learning to read despite conventional instruction, adequate intelligence and sociocultural opportunity….” Critchley, M. (1970), ‘The dyslexic child’ Springfield Ill. or language based: Shaywitz B. A.et al.(1992). J. Child Neurol.

Collaborators: -Jerry Lettvin, MIT -Olga Zegarra-Moran in SISSA, Trieste Italy, (at the time). -Manfred Fahle, in Tübingen, Germany, (at the time). In: IRCCS “E. Medea”, La Nostra Famiglia, Bosisio Parini, Italy Silvia Pesenti Maria Luisa Lorusso Carmen Cattaneo Raffaella Galli Andrea Facoetti Massimo Molteni Uberto Pozzoli

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The form-resolving field (FRF) of English-native adults angular distance from center of gaze [degrees] correct recognition [%] ordinary readers (OR)

The form-resolving field (FRF) of English-native adults angular distance from center of gaze [degrees] correct recognition [%] ordinary readers (OR) dyslexics OR

The form-resolving field (FRF) of English-native adults angular distance from center of gaze [degrees] correct recognition [%] ordinary readers (OR) dyslexics the differences in recognition

The form-resolving field (FRF) of English-native adults angular distance from center of gaze [degrees] correct recognition [%] ordinary readers (OR) dyslexics the extent of recognition difference

Numerical characterization of the FRF: criterion C2 angular distance from center of gaze [degrees] correct recognition [%] +

Telling dyslexics and ordinary readers apart: the diagnostic power of C2. C2 The C2 criterion tells 87% of the tested person correct.

correct recognition [%] The FRF’s of the three Boder type dyslexics angular distance from center of gaze [degrees]

Correct recognition % The FRF’s of the three Bakker type dyslexics angular distance from center of gaze [degrees]

The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey, a scribe uses a narrow field to write and a painter or architect uses a variable field to arrange an ensemble into a whole. Each discipline of seeing take practice. But suppose, like a dyslexic, you have a strategy inappropriate to reading. When ordinary readers look at text

The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey, a scribe uses a narrow field to write and a painter or architect uses a variable field to arrange an ensemble into a whole. Each discipline of seeing take practice. But suppose, like a dyslexic, you have a strategy inappropriate to reading. When dyslexics look at text

The form-resolving field (FRF) of English-native adults angular distance from center of gaze [degrees] correct recognition [%] ordinary readers (OR) dyslexics OR

The form-resolving field (FRF) of Hebrew-native adults angular distance from center of gaze [degrees] correct recognition [%] ordinary readers (OR) dyslexics OR

The form-resolving field (FRF) of a “conditional dyslexic” angular distance from center of gaze [degrees] correct recognition [%] In the “alert” phase

in the “tired” phase tired alert The form-resolving field (FRF) of a “conditional dyslexic” angular distance from center of gaze [degrees] correct recognition [%] In the “alert” phase

Demonstrating lateral masking N x TENET Keep your gaze on the x without moving your eyes

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Demasking

The regimen of practice for learning a new perceptual strategy The practice comprises two parts: Novel, small-scale, hand-eye coordination tasks like painting, drawing, modeling, embroidery etc.. Reading with a window-mask.

The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey, a scribe uses a narrow field to write and a painter or architect uses a variable field to arrange an ensemble into a whole. Each discipline of seeing take practice. But suppose, like a dyslexic, you have a strategy inappropriate to reading. The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey, a scribe uses a narrow field to write and a painter or architect uses a variable field to arrange an ensemble into a whole. Each discipline of seeing take practice. But suppose, like a dyslexic, you have a strategy inappropriate to reading.

The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey, a scribe uses a narrow field to write and a painter or architect uses a variable field to arrange an ensemble into a whole. Each discipline of seeing take practice. But suppose, like a dyslexic, you have a strategy inappropriate to reading. The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey, a scribe uses a narrow field to write and a painter or architect uses a variable field to arrange an ensemble into a whole. Each discipline of seeing take practice. But suppose, like a dyslexic, you have a strategy inappropriate to reading. Reading with a window-mask

The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey, a scribe uses a narrow field to write and a painter or architect uses a variable field to arrange an ensemble into a whole. Each discipline of seeing take practice. But suppose, like a dyslexic, you have a strategy inappropriate to reading. The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey, a scribe uses a narrow field to write and a painter or architect uses a variable field to arrange an ensemble into a whole. Each discipline of seeing take practice. But suppose, like a dyslexic, you have a strategy inappropriate to reading. Reading with a window-mask

The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey, a scribe uses a narrow field to write and a painter or architect uses a variable field to arrange an ensemble into a whole. Each discipline of seeing take practice. But suppose, like a dyslexic, you have a strategy inappropriate to reading. The way we see is not determined by what we want to see but how we have learned to practice seeing. There are several strategies that we pick between depending on what we have learned to see, and we switch between them as the task changes. So for example, a hunter uses a wide field of vision to locate prey, a scribe uses a narrow field to write and a painter or architect uses a variable field to arrange an ensemble into a whole. Each discipline of seeing take practice. But suppose, like a dyslexic, you have a strategy inappropriate to reading. Reading with a window-mask

TübingenBrookline experimental-dyslexics reference-dyslexics Grades Improvements in reading after 3 months of practice

Correct recognition % The FRF of the experimental dyslexics before after OR before and after 3 months of practice angular distance from center of gaze [degrees]

word ident. comprehension word attack before after before and after practice grades Reading levels of 14 adult dyslexics grades improvements ("0" is the expected level for each individual) * * * ( * - denotes significance better than 0.05)

The form-resolving field (FRF) of English-native Dyslexics before and after practice angular distance from center of gaze [degrees] correct recognition [%] before after OR

G-L practice Logopedia before after Accuracy of reading SD improvements * ( reading levels are indicated by standard deviation (SD) units from the expected norm) G-L practice Logopedia before after Speed of reading SD improvements * Reading of passages and word-lists by dyslexic children

Reading non-words improvements

86420 G-L practice Logopedia before after Fusing syllables to words errors improvements * Measuring auditory-phonemic skills 6420 G-L practice Logopedia before after Omitting syllables from words errors improvements *

Smooth and jagged letters angular distance from center of gaze [degrees] correct recognition [%] The FRF of adult ordinary readers when presented with smooth letters jagged letters jagged

-Dyslexics and ordinary readers differ in their visual and auditory perceptual strategies. A wide strategy for dyslexics and a narrow one for ordinary readers. -The strategies differ mainly in their neural tuning and coding specificity, that leads to different distributions of lateral masking and the pattern of attention. -The wide perceptual strategy explains why reading ordinarily is difficult or almost impossible for dyslexics. -Dyslexics are able to learn a narrow strategy for reading by practice. -This practice results in cross sensory-modality learning. Main points

initial final Grades The initial and final reading scores of 24 dyslexic children

The form-resolving field adults angular distance from center of gaze [degrees] correct recognition [%] Ordinary readers “speed readers” OR speed readers

Line drawings of objects used as stimuli

The form-resolving field (FRF)of adult ordinary readers angular distance from center of gaze [degrees] correct recognition [%] large letters “objects” letters objects