Language Organization Classic model

1. Language OrganizationClassic model Sensory perception--comprehension (WA)--Broca’s (formulation, motor plan)--motor cortex (final common pathway)

2. Language OrganizationClassic model Sensory perception--comprehension (WA)--Broca’s (formulation, motor plan)--motor cortex (final common pathway)

3. Classical conception of aphasia. Paul Broca (1824-1880). Communication a la Societe d’Anthropologie (1865)” Je vous ai communique…….dix observations d’aphemie dans lesquelles on a trouve a l’autopsie des lesions diverses de la 3me circonvolution frontale…..Je persiste a penser que l’aphemie verbale, c’est a dire la perte de la parole sans paralysie des organes de l’articulation et sans destruction de l’intelligence est liee aux lesions de la 3me circonvolution frontale. Ma communication est relative a la singuliere predilection de l’aphemie pour l’hemisphere gauche du cerveau” Mr.Leborgne =Tan-Tan died 4/17/1861

4. Mr. Leborgne died 4-17-1861 11am at the age of 51. MRI of Leborgne 4-15-1994

5. Voxel-based Lesion-Symptom Mapping (VLSM): sample maps Fluency Comprehension Bates, Wilson, Saygin, Dick, Sereno, Knight & Dronkers, 2002

6. Disruption model of language function “Broca’s Area”: PIFG “Wernicke’s area”: PT/IP Reading Area: Angular Gyrus Basal Temporal Language Area

7. Frontal regions 44 inf 44/6 9/6 Exners area 46 45 47 6 medial Temporal regions 41/42 22 21/20 37 Parietal: 40 39

8. 1 1 2 2 3 5 8 4 6 6 3 3 7 7 6 9 9 10 10 8

9. Basal Temporal Language Area • Mills Naming Center; Nielson’s language formulation center • Involved in object naming • Lesion: Pure anomic aphasia • Category specificity in more anterior areas • Believe pathways project ant/sup through insula 1 1

11. BTLA is difficult to image: • Major artifacts; need to indicate where you haven’t signal- false negative risk • Object naming area: verb generation is NOT a good activator of this region

12. Wernicke’s area(s) • Inferior portion: middle temporal gyrus/superior temporal sulcus • Often bilateral activation • Superior portion: superior temporal gyrus/supramarginal gyrus • Posterior/adjacent to TTG 2 2 3 3

15. Wernicke’s area(s) • Critical for auditory language comprehension; word recognition, sequencing phonemes • Lesions: grammatic speech; multiple paraphasias; • Superior lesions: phoneme selection deficits, sequencing deficits; reading problems • Activations often quite deep in sulci • Output travels posterior and superior in arcuate fasciculus • Lesions of white matter tracts into and out of the region can lead to serious deficits;These can be quite distal to the cortical processing areas • Object naming, word generation --poor activators

16. Arcuate fasciculushttp://da.biostr.washington.edu/da.html

17. Frontal language areas 5 8 4 6 6 6 9 9 10 10

18. Bookheimer 2003 Annual Rev. Neurosci.

19. Orbital frontal cortex: 47/45 • Arguments about its job: semantics; verbal selection; selection generally • Integration of (semantic) information • Lesion/electrical stimulation: semantic integration deficits: normal object naming, grammatic speech; impaired auditory responsive naming 4

20. “Broca’s” area: 44 and 45 • Superior to IFS/PCS border, inferior to sylvian • Focal region; variable in precise location; some language specificity • Must exist! • Lesions: grammatic output; naming; generation; phoneme monitoring; syntax comprehension; effortful speech; arrest or anomia with stimulation 6

23. A B

24. Phonology in IFG Gelfand and Bookheimer, Neuron 2002

25. reverse delete match

27. Exner’s Area • 6/8 in MFG/PMC • Associated with pure agraphia • Appears in many tasks 7 8

28. Longcamp et al NeuroImage 2003

29. Exner’s area vs FEF Phoneme to grapheme task; saccades Matsuo et al Neurosci Lett 2003 Exner’s FEF

31. Stimulated region Tumor Stimulated region

32. Angular Gyrus • Critical for reading • Integrates auditory and visual information • Pathways from IT to AG, oCC-AG, AG-SMG, all vulnerable 7 Reading phrases

34. Supplementary Speech Area (Pre-SMA, Speech SMA) • Important in initiating a motor speech plan • When removed, get a complete arrest of speech; lesions may reduce initiation or lead to a “dwindling aphasia”; comprehension is normal • Easily reorganizes to intact RH when the callosum is intact- 1-3 weeks 10

35. Anterior Insula • Very often bilaterally symmetric • When lesioned bilaterally (and selectively): pure apraxia of speech • Lesions of area (nearby white matter, IFG, striatum) lead to profound expressive aphasia • Do not use to establish laterality; don’t recommend to remove it either 5

36. Dorsolateral Pre-frontal Cortex • Not a language area • Will show activation, sometimes unilateral, especially on generation tasks • Lesions show reduced fluency; stimulation often produces perseverations • Don’t use for laterality; often removed in surgery 8

37. Language 2 • Reading system and reading disorders • Right hemisphere contributions to language • Prosody • context

38. Reading System • Major issue in reading: 1 or 2 pathways • Call this the Dual Route model • Was controversial before functional imaging- now its pretty well accepted • Based on differences in acquired alexia errors

39. Types of Alexia • Phonologica, literal or Surface • Patients read in a letter-by-letter fashion • They sound out each word • Errors: they can read pronounceable nonsense words “migbus”; cannot read irregular words like “yacht” • Damage likely to the visual recognition system in the LH: cant recognize whole words

40. Alexia cont. • Alexia type 2: visual, semantic alexia • Can read whole words • Can read irregulars like yacht and pharoah • Cannot read nonsense words • Strong frequency effect- more likely to read common than uncommon words; better at concrete nouns • Make visual or regularization errors: lit = light; groal=goal, etc. • Apparently have damage to phonological to orthographic conversion system or to phonological system

41. Rarer alexias • Global alexia: affects all reading. AG lesions or WM exiting visual cortex in LH • Deep dyslexia: associated with large LH lesions- characterized by global dyslexia with: • Visual errors: gird=“girl” • Derivational errors: architecture= architect • Semantic errors: orchestra=symphony • Superior at reading concrete nouns • Suggested to represent some primitive RH whole word recognition capabilities

42. Rarer alexias, cont. • Alexia without agraphia or occipital alexia: • Most other acquired alexics have impaired writing similar to reading • Alexia without agraphia associated with 2 lesions: one in the left occipital cortex and one in the posterior callosum • Disruption of visual information into the LH reading system. Usually accompanied by a field or quadrant cut • Can write, but cant read what they write

43. Developmental dyslexia • Most are similar to the surface alexic • Difficulty with auditory processing • Poor at grapheme to phoneme conversion • Lousy at reading nonwords • Slow readers; often learn by whole-word approach • Rarer, there are visual types and often some with general language difficulties

44. Anatomy of Reading Inferior Frontal Gyrus Supramarginal Gyrus (40) Angular Gyrus (39) Superior Temporal Gyrus (posterior)42,41;22 Temporal/Occipital Junction 21/20/37

45. Dual Routes • Inferior Route: • Occipital V1-V2-V3-IT-insula/44/47 • Superior Route • V1-V2- AG-ST- IFG 44/6 • Interaction through AG • Writing: includes SMG and Exner’s area (46/6 anterior to M1 hand)

47. Right hemisphere contributions to language • Some evidence that early right brain lesions can be more detrimental to language development than LH lesions • LH may process more rapid information. RH may maintain a context and provide emotional cues to global meaning • Some evidence that the ear itself is tuned for more rapid auditory information in LH or infants (Sininger 2004 Science).

48. Prosody Paradigm • Selective attention/stimulus matched paradigm • For the 2 prosody conditions: • “Do the sentences sound alike” regardless of literal meaning • For the SC condition: • “Do the sentences mean the same thing” regardless of the sound

49. Affective prosody vs. others

50. Linguistic vs. Affective