Download
the brain might read that way n.
Skip this Video
Loading SlideShow in 5 Seconds..
The Brain Might Read That Way! PowerPoint Presentation
Download Presentation
The Brain Might Read That Way!

The Brain Might Read That Way!

204 Vues Download Presentation
Télécharger la présentation

The Brain Might Read That Way!

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. The Brain Might Read That Way! Donald J. Bolger Assistant Professor

  2. Reading the Brain

  3. Outline Frameworks of Reading Development Theories of Reading Impairment Cortical Models of Reading Development Cross-Sectional fMRI Studies of Reading Development Spelling-sound processing in Typically developing versus Impaired readers Role of Executive Functions in Impaired Reading Training of Executive Functions

  4. Letter identification system Orthographic Input Lexicon Grapheme-phoneme rule system Semantic system Phonological Output Lexicon Phoneme System Route Models of Reading Hypotheses • 2 Routes: • G-P-C (sub-lexical) • Lexical • Determined by RULES • Encapsulate Modules • Feedforward Early visual feature analysis system C-A-T Letter identification system CAT /k/ - /a/ - /t/ Orthographic Input Lexicon Grapheme-phoneme rule system Semantic system Phonological Output Lexicon /k-a-t/ Phoneme System Speech

  5. Interactive Models of Reading: Parallel Distributed Processing Hypotheses • Single Mechanism • Instance-based • Interactive (Feedback) • No explicit lexical/sublexical distinction • Patterns emergent Semantics Orthography Phonology /gōť/ GOAT

  6. Bootstrapping of Skills CAT A = /a/ T = /t/ C = /k/

  7. Sub/Lexical Pattern Development BOAT GOAT *OAT= /ōť/

  8. Outline Frameworks of Reading Development Theories of Reading Impairment Cortical Models of Reading Development Cross-Sectional fMRI Studies of Reading Development Spelling-sound processing in Typically developing versus Impaired readers Role of Executive Functions in Impaired Reading Training of Executive Functions

  9. Reading Impairment Developmental or Phonological Dyslexia • Diagnosis • Normal range for spoken language comprehension • Below normal achievement for reading • Word Identification, fluency, reading comprehension • Phonological Deficit • Failure to perceive phonemes (phonological awareness) • Failure to connect letters-sounds • Fail to read (decode) irregular and low frequency words

  10. Reading Impairment Developmental or Phonological Dyslexia • Phonological Deficit • Not seen in Italian and German (regular orthographies) • Problem with fluency • Implicit vs. Explicit pattern processing (phonology) • Explicit: simple letter-sound pattern (Intact) • Implicit: derive sublexical patterns from wordforms

  11. Outline Frameworks of Reading Development Theories of Reading Impairment Cortical Models of Reading Development Cross-Sectional fMRI Studies of Reading Development Spelling-sound processing in Typically developing versus Impaired readers Role of Executive Functions in Impaired Reading Training of Executive Functions

  12. The Reading Brain: The Early Days Phonology Contrasts: PLOK > CDTR Rhyme Tasks Orthography Contrasts: CDTR > $#%@ Orthographic judgments Semantic Contrasts: SING > PLOK Meaning-based Judgments Meta-image of contrasts involving words > null control state. Bolger, Perfetti & Schneider (2005) Human Brain Mapping.

  13. Development of Reading Grapheme-Phoneme Rule System Phonological Output System Semantic System Early Visual Analysis Orthographic Lexicon Dorsal Route (YELLOW): early developing, letter-sound decoding Ventral Route (BLUE): later developing automatic lexical processing Pugh et al. (2001) Journal of Communication Disorders

  14. Interactive Cortical Model Auditory Association Secondary Motor (articulatory) Supra-modal Processing Primary Visual Processing Visual Association Reading Network  Associative Regions Tuned to relationships between Orth – Phon – Sem

  15. Where are written words identified ? Focus on the left fusiform region (VWFA) • Dubbed “Orthographic Lexicon” • Activated for tasks of visual words vs. … • False Fonts (Tagamets et al., 2002) • Letter strings (Cohen et al., 2000) • Auditory words (Price, 2000) • Increases with reading skill (Shaywitz et al., 2004; Pugh et al., 2000) • Inconsistent findings for Words vs. Pseudowords • Pseudowords > Words (Fiez et al., 1999) Hypothesis: VWFA reflects interactivity between orthography and phonology (semantics?)

  16. The Left Fusiform (VWFA) Region Bolger, Perfetti & Schneider (2005) Human Brain Mapping. Overlapping Meta-Images: Letter/Letterstrings (XYZF) vs. Null Pseudowords (PLOK) vs. Null Japanese Kana (syllabary) vs. Null Japanese Kanji (characters) vs. Null Chinese Characters vs. Null Words (MINT) vs. Null Pseudowords (PLOK) vs. Null

  17. Outline Frameworks of Reading Development Theories of Reading Impairment Cortical Models of Reading Development Cross-Sectional fMRI Studies of Reading Development Spelling-sound processing in Typically developing versus Impaired readers Role of Executive Functions in Impaired Reading Training of Executive Functions

  18. The Development of word form representations in Cortex • How does the brain process sub-lexical spelling-sound correspondences? • Does phonology constrain the processing of orthographic recognition? • Does this ability appear to develop with skill?

  19. Representational Properties in Cortex: Repetition Effects Repetition effects show the sensitivities and characteristics of cortical regions Example: Fusiform Face Area Responds to Identity

  20. Effects of sub-lexical priming in cortexBolger et al. (submitted) + 1700ms MINT 800ms + 200ms PINT 800ms • Participants: 46 subjects (20♀, 26♂)between ages of 9-15 yrs. All normal range reading ability. • Prime-Target rhyme judgment Task: • Do prime (pint) and target (mint) rhyme? • Conditions: • O+P+: walk – talk • O+P-: pint – mint • O-P+: grade – laid • Event-related Design • DeconvolvedPrime and Targets

  21. Repetition Effects: Prime > TargetWalk-Talk vs. Pint-Mint + Jazz-Has(O+P+) (O+P-) (O-P+) Left Fusiform Gyrus

  22. Hemo-dynamic Response Function (HRF)Prime-Target in Left Fusiform Gyrus O+P+:FINE - LINE O-P+:JAZZ - HAS O+P-:PINT - MINT Prime Target

  23. Brain-Behavior CorrelationsPhonological Awareness Skill = Difference in Priming Effects Ex: walk/talk > pint/mint (O+P+) (O+P-)

  24. Participants: 40 subjects ages of 9-15 yrs. All normal range reading ability. Prime-Target rhyme (spelling) judgment Task: Do prime and target rhyme (spelled the same)? Conditions: O+P+: fine – line O+P-: pint – mint O-P+: grade – laid Event-related Design Deconvolve Prime and Targets Repetition Priming Effects of Orthographic Information in a Spoken Language TaskFan Cao, K. Khalid, R. Zaveri, D.J. Bolger, & J.R. Booth (HBM 2009) + 1700ms MINT 800ms + 200ms PINT 800ms

  25. Repetition Priming Effects Comparison of Priming Effects (P>T) O+P+ Vs. O+P-: Fine – Line vs. Pint – Mint  Change in Phonology increased activation in middle frontal and ACC to target stimuli

  26. Repetition Priming Effects Comparison of Priming Effects (P>T) O+P+ Vs. O-P+: Fine – Line vs. Grade – Laid  Change in Orthography increased response in fusiform to target

  27. Correlation of Priming Effects with Age Differential of O+P+ > O-P+ with Age

  28. Summary • Orthographic processing in the brain is shaped by phonological information. • Left Fusiform (VWFA) sensitive to sub-lexical spelling-sound patterns occur with statistical regularity • These effects are modulated by skill as well as age suggesting that they are based on experiential factors

  29. Outline Frameworks of Reading Development Theories of Reading Impairment Cortical Models of Reading Development Cross-Sectional fMRI Studies of Reading Development Spelling-sound processing in Typically developing versus Impaired readers Role of Executive Functions in Impaired Reading Training of Executive Functions

  30. Spelling-sound relationships in typically achieving & impaired readers How does the brain handle differences in spelling-sound relationships? Do impaired readers learn these relationships?

  31. Consistency Effects Phonological Consistency Spelling-to-Sound seat /ɛ/ /ɛ/ me /i/ /i/ see Sound-to-Spelling Orthographic Consistency • Phonological • Inconsistent mappings from spelling to sound (i.e. seat and sweat) • Orthographic • Inconsistent mappings from sound to spelling (i.e. seat and see) • Both Produce: • increased RT • decrease Accuracy • Lexical decision & Naming tasks

  32. X = -42 SPL/IPL (BA40/7) IFG/MiFG (BA44/45/47/9) STG/MTG (BA39) X = -6 STG/MTG (BA22) PCC/PreCun (BA29/7) ACC/MeFG (BA32/24/6) FG (BA37) Activation Correlated with Consistency Negative Activation - Inconsistency Positive Activation - Consistency

  33. Development of Consistency Effects with Reading Skill Left Fusiform Gyrus Accuracy correlated with activity in the left fusiform for the rhyming task.

  34. Bilateral MiFG ACC/ MeFG IFG Bilateral IFG/Insula IFG/PrCG MiFG ITG/FG ITG/FG Phonological Consistency Orthographic Consistency Both Differences between Impaired and Non-impaired readers Main Effects: Inconsistency Differences: Normal vs. Impaired Main Effects: Inconsistency Differences: Normal vs. Impaired

  35. = Impaired Readers =Normally Achieving Readers Brain-Behavior CorrelationsDecoding Ability and Orthographic Consistency Similar effects in Frontal Cortex with Phonological Awareness

  36. 1700ms + + 800ms MINT 200ms + + PINT PINT 800ms 800ms Neural Correlates of Orthographic and Phonological Consistency in Auditory WordsBolger et al., (under revision) • 46 ND children (20 girls), age 9-15 (mean 11.3) • Visually presented Rhyming & Spelling Tasks • Event-related design • Item-level regressor Consistency = Friends/(Friends+Enemies) • Analyzed neural response to primes • Deconvolved Primes and Targets as individual predictors

  37. Main Effect of Inconsistency IFG/MiFG (BA 44/9) ACC/MeFG (BA 8/6) IPL (BA 40/7) IFG/MiFG/insula (BA 44/9/6) STG (BA 22) FG (BA 20) IPL (BA 40/7)

  38. Consistency Effects for Auditory Words: Normal vs. Impaired Readers NORM - IMPAIRED NORM - IMPAIRED Z = 33 L MeFG Orthographic (0,39,33) L MiFG Phonological (-42,9,33) L MeFG L MiFG Z = 33 Z = 33 L MiTG Phonological (-45,-42,-6) R MiTG Orthographic (57,-51,0) L MiTG R MiTG Y = -42.2 Y = -51.2

  39. Reading Impairment: Causes • Phonological Deficit • Failure to perceive phonemes (phonological awareness) • Failure to connect letters-sounds • Not seen in Italian and German (regular orthographies) • Attentional Processing Deficit • Comorbidity with ADD/ADHD • Complex set of attentional processes impact reading & math performance • Neural system underlying both

  40. The Dyslexic Brain Hypoactivation of Wernicke’s Area

  41. Cross-Language Effects in Dyslexia. Paulesu et al (2000) Dyslexics Normals

  42. What is the problem? • Hearing speech sounds? • Underlying auditory processing deficit? • Seeing the letters • Holding the letters and there positions in mind? • ACT vs. CAT • Disruption to the circuitry underlying both • Attention & Executive Function…

  43. Outline Frameworks of Reading Development Theories of Reading Impairment Cortical Models of Reading Development Cross-Sectional fMRI Studies of Reading Development Spelling-sound processing in Typically developing versus Impaired readers Role of Executive Functions in Impaired Reading Training of Executive Functions

  44. Reading Impairment & Executive Function • Complex cognitive skills are sub-served by our capacity to: • Selectively attend to relevant information, • Inhibit responses to irrelevant information, • Maintain information over time for processing • 3 Critical mechanisms of Executive Function • Selective attention • Response inhibition • Working memory

  45. Role of Orienting of Attention

  46. Inhibition of Irrelevant Stimuli

  47. Role of Selective Attention