1. Cerebral Cortex 2

2. Heteromodal Association Cortex
Multimodal association cortical areas
Integration of sensory information for multiple modalities
Most of neocortex in humans
NO direct motor or sensory areas
Do not receive direct sensory input
Do not project to LMN

3. Bidirectional connections with
Motor and sensory association cortex
Limbic cortex

4. Association Cortex Involved in higher intellectual functions
Abstract reasoning
Complex planning
Personality
Processing of memory
Generation of emotions

6. Higher Cortical Functions
Hemispheric specialization
Some functions located on one side of the cerebral cortex
May speed up processsing if it is all done on one side

7. Handedness 90% right-handed – left cerebral hemisphere is dominant
Simple movements – contralateral hemisphere
Skilled, complex tasks – dominant hemisphere
Lesions of left hemisphere more often associated with apraxia – difficulties formulating skilled movements

8. Language Left hemisphere is usually dominant for verbal communication
Language function may be more bilateral
Tend to recover language faster

9. Language Non-dominant side Non-verbal communication
Emotional aspects of events and language
Musical perception

10. Attention Both sides involved in attention for the contralateral side
Right side attends to both sides
R side stroke will produce inattention to the left

11. Dominant hemisphere
(usually L)
Non-dominant hemisphere (Usually R)
Language
Prosody (emotion conveyed by tone of voice)
Skilled motor formulation (praxis)
Visual-spatial analysis and spatial attention
Arithmetic: sequential and analytical calculating skill
Arithmetic: ability to correctly line up columns of numbers on a page

12. Dominant hemisphere
(usually L)
Non-dominant hemisphere (Usually R)
Musical ability: sequential and analytical skills in trained persons
Musical ability: in untrained persons. Complex musical pieces in trained musicians
Direction: following a set of written directions in sequence
Direction: finding one’s way by overall sense of spatial orientation

13. Higher Order Cerebral Function
Language
Attention and spatial processing
Frontal lobes
Visual processing
Attention and Awareness

14. Language Brain regions involved Primary auditory cortex
Wernicke’s area (part of auditory association cortex)
Primary motor cortex for the face
Broca’s area (association cortex)
Connections between Broca’s and Wernicke’s areas
Arcuate fasciculus

15. Wernicke’s Area Primarily involved in language comprehension
Maps sounds to meaning in order to produce meaningful language (lexicon)
Comprehension
Production

16. Broca’s area Higher level aspects of speech formulation and planning
Correct syntax of language comprehension and production

17. Language – Non-dominant hemisphere
Connected with dominant hemisphere through corpus callosum
May have difficulty aspects of language imparted by tone of voice
May have difficulty producing emotionally appropriate expression

18. Aphasia Deficit in language processing
Injury to language dominant hemisphere
Affects both spoken and written language

19. Broca’s Aphasia Damage to Broca’s area or surrounding structures
Decreased fluency of spontaneous speech
Phrase length of fewer than 5 words
More content words (nouns) than function words (prepositions, articles, etc.)
Can be tested by word generation tasks
FAS (12 or more words)
Prosody is frequently lacking

20. Comprehension usually relatively intact
Naming difficulties
Impaired repetition
“No ifs, ands or buts”
Comprehension usually relatively intact
Difficulties where syntax matters – passive voice
Writing and reading aloud – similar to speaking difficulties – slow, agrammatical, and effortful

21. Frustration and depression common Associated problems
Dysarthria
Hemiplegia on R side
Apraxia
Often affects left-side and oral-buccal-lingual structures
Stroke – MCA (superior division)

22. Wernicke’s Aphasia Lesion – Wernicke’s area and adjacent structures
Stroke – MCA (inferior division)
Impaired comprehension
Do not respond appropriately to questions or commands
May respond to some commands about axial muscles

23. Normal fluency, prosody and grammatical structure
Sentences do not have meaning
Paraphasic errors
Replace word with one of a similar meaning
Replace part of a word with a similar sound
Neologisms – make up new word
Impaired naming

24. Disconnect from Broca’s area Reading and writing – similar deficits
Impaired repetition
Reading and writing – similar deficits

25. Associated dysfunctions
Contralateral visual field cut
Apraxia may be present – difficult to assess due to aphasia
Often appear unaware of disorder
May exhibit angry or paranoid behavior

26. Syndromes related to aphasia
Alexia and agraphia
Apraxia
Aphemia
Cortical deafness
Pure word deafness
Nonverbal auditory agnosia

27. Alexia and agraphia Reading and writing impairments
Deficits in central language processing
Patients with aphasia have agraphia
Deficits in patients with aphasia tend to mirror the aphasia

28. Writing With Broca’s aphasia With Wernicke’s aphasia
Effortful, agrammatical and sparse
With Wernicke’s aphasia
Fluent, paraphasic and largely incomprehensible

29. Apraxia
Ideomotor apraxia – inability to carry out an action in response to a verbal command, in the absense of any comprehension deficit, motor weakness or incoordination
Ask patient to carry out an imaginary action
Awkward looking attempts
Perform tasks ineffectually

30. 1/3rd of patients with aphasia have some apraxia
Different regions of the body (orofacial, proximal, or distal limb) may be affected differently

31. Aphemia (Verbal apraxia)
Small lesion in Broca’s area
Motor speech deficits
Writing is intact
Verbal apraxi – aphemia that occurs as a developmental disorder in children

32. Cortical deafness
Lesion to bilateral auditory corex

33. Pure Word Deafness AKA verbal auditory agnosia
Can identify non-verbal sounds
Cannot understand spoken words
Can read and write normally
Lesion to auditory cortex of dominant hemisphere which extends deep to the subcortical white matter

34. Non-dominant hemisphere Attention and spatial processing
Usually Right side
Global Attention
Vigilance, Concentration, Generalized Behavioral Arousal
Selective or Directed Attention
Focusing attention on a specific domain

35. Cerebral Hemispheres and Attention
Involves both cerebral hemispheres
Right cerebral hemisphere is more important for most people
L side – responds to R
R side – responds to L and R
Opposite role of premotor cortex
R side – Left hand
L side – L and R hand

36. Slight left attentional bias

37. Effects of Injury on Attention
Right hemisphere lesion
Severe left neglect
Left hemisphere lesion
Minimal right neglect
Bilateral hemisphere lesion
Severe right neglect