Week 5 Flashcards
(37 cards)
1
Q
Lateralisation of the cerebral cortex
A
- The cortical regions are responsible for a particular psychological function are located in only one of the hemispheres OR
- Both hemispheres contribute, but the contribution of one is more important than or different to that of the other
2
Q
Corpus callosum
A
- Bundle of fibres that crosses over between the two hemispheres
3
Q
Divided visual field technique
A
- Relies on the visual anatomy of the pathway of the eye to the cerebral cortex
- Image showed briefly
- Sperry
4
Q
Split brain study
A
- Presented in the right visual field – processed in the left hemisphere – verbal
- Presented in the left visual field – processed in the right hemisphere – visual
5
Q
Block study
A
- Views a pattern made with squares and told to recreate using blocks
- Left hand – can complete it – right hemisphere
- Right hand – find it hard – left hemisphere
- Right hemisphere linked to visuospatial tasks
6
Q
Lateralisation of language – Wada test
A
- Deactivate one hemisphere
- Person loses power of speech if left hemisphere is put to sleep
- However, can grab things with the left hand – right hemisphere
7
Q
Language being across the brain
A
- In most people tested
- Fundamental components of language are located in the left hemisphere
- Can be in the right hemisphere – left handed
8
Q
Broca
A
- Damage to Broca’s area
- Problems with language production – broca’s aphasia
- Doesn’t seem to effect comprehension
9
Q
Broca’s area location
A
- An area in the left frontal lobe
- Next to the motor cortex
10
Q
Broca’s aphasia symptoms
A
- Slow, laboured speech output
- Some degree of anomia
- Paraphasic errors
- Telegraphic speech
- Repetition of multisyllabic words impaired
- Aware of deficit and easily frustrated
11
Q
Wernicke
A
- Can produce fluent, grammatical speech
- Difficulties comprehending spoken or written language
- Wernicke’s aphasia
12
Q
Wernicke’s aphasia symptoms
A
- Problems understanding spoken and written language
- Speech is fluent with normal grammar
- Phonemic and semantic paraphasia – substituting words that related to eachother
13
Q
Wernicke’s area
A
- Damage located in the posterior part of the superior temporal gyrus
14
Q
Wernicke-Geschwind model
A
- Model of language organisation in the brain
- It shows how different region with different functions interact in language production and comprehension
15
Q
Wernicke-Geschwind Broca’s area
A
- Formulates the speech plan implemented by motor cortex
- Turns intended meanings into motor plans for the speech articulators
16
Q
Wernicke-Geschwind Wernicke’s area
A
- Controls language comprehension and processing of meaning
- Requires language to be coded in a specific way
17
Q
Wernicke-Geschwind angular gyrus
A
- Provides visual language in the appropriate code to Wernicke’s area
18
Q
Wernicke-Geschwind auditory cortex
A
- Provides spoken language in the appropriate code to Wernicke’s area involved in sensory processing of speech sounds
19
Q
Wernicke-Geschwind motor cortex
A
- Involved in the production of articulatory movements
20
Q
Wernicke-Geschwind arcuate fasciculus
A
- Bundle of axons linking Wernicke’s and Broca’s area
- Allows us to read aloud and repeat what others say
21
Q
Wernicke-Geschwind repeating spoken words
A
- Auditory cortex processes speech sounds
- Meaning is accessed in Wernicke’s area
- Signals are transmitted via arcuate fasciculus to Broca’s area
- Broca’s area forms a speech-type representation of the word
- Instructions are sent to the motor cortex to execute action
22
Q
Wernicke-Geschwind repeating written words
A
- Word is processed by the visual cortex
- Information is transmitted to the angular gyrus.
- The visual code is converted into a phonological in the angular gyrus
- The phonological representation is interpreted in Wernicke’s area
- Instructions are sent to the motor cortex to execute action
23
Q
Conduction aphasia lesion
A
- damage to the arcuate fasciculus
24
Q
conduction aphasia symptoms
A
- Good comprehension and production
- Repetition and reading aloud has paraphrasic errors and may fail with multisyllabic or nonsense words
25
Global aphasia
- damage to temporal and frontal areas
- poor comprehension, little speech and impaired repetition
26
Issues with Wernicke-Geschwind Model
- it is rare to find patients with damage confined to those regions
- the model is oversimplified
- functional distinctions aren't mirrored in the brain
27
Issues with Wernicke-Geschwind Broca's area
- it is only partly responsible for the ascribed function
- recent study of Broca's patient showed damage to the insula cortex, other deep white and grey matter and the forebrain nuclei
28
Issues with Wernicke-Geschwind Wernicke's area
- damage to Wernicke's area alone produces mild symptoms
- initial swelling may cause the aphasia
- Visual information can reach Broca's area without going via the angular gyrus and Wernicke's area
29
Lichtheim's model
- interpretation and comprehension of language required conceptual knowledge stored in a region outside Broca and Wernicke's areas, interconnected by white matter tracts
- 3 types of disconnection damage could occur
30
Lichtheim damage to pathway from Wernicke's to Broca's areas
- this would be damage to the arcuate fasciculus
- causes conduction aphasia
31
Lichtheim damage to pathway from Wernicke's to conceptual area
- impairs comprehension of speech (but not repetition)
-> transcortical sensory aphasia
32
Lichtheim damage to pathway from conceptual area to Broca's
- similar to Broca's aphasia, no repetition issues
obsessive repetition of heard phrases
-> transcortical motor aphasia
33
electrical stimulation methods
- Electrodes applied directly to the cortical surface whilst a patient was in surgery
(Penfield)
34
electrical stimulation LH
- aphasic arrest areas correspond roughly to Broca's, Wernicke's and angular gyrus
35
electrical stimulation of rostral regions
- strong stimulation- stop a patient talking
- weak stimulation- produce hesitant speech, mild anomia
- -> production issues
36
electrical stimulation of posterior regions
- speech arrest or words confusion
- -> comprehension issues
37
Right hemisphere linguistic function
- related to rhythm and expressive intonation in speaking and comprehension (surrounding meaning and emotional state of the speaker)
