Lateralisation and Language Flashcards
Right hemisphere
Bigger than left - contains more grey matter
Corpus Callosum
set of axons between left and right hemispheres
damage to this interferes with exchange between the hemispheres
Language
Most lateralised task
Left brain
Dax
Said left hemisphere was responsible for speech
Broca’s area
Paul Broca
Speech production
Broca’s aphasia refers to serious impairment in language production
Omission of most pronouns, prepositions, conjunctions etc..
Trouble in understanding
Wernicke’s area
Receptive aphasia
Language comprehension
Poor comprehension
Speech sounds normal but have no mean - word salas
Brodmann’s area
Based on neuronal architecture
What connects Wernicks’s area and Brocas
The arcuate fasciculus
Damage here causes conduction asphasia (inability to repeat words just heard)
Comprehension and speech normal
Geschwind’s territory
Geschwind’s territory. a newly discovered brain region, implicated in language. This area connects Broca’s and Wernicke’s areas via a region of the parietal lobe of the cortex, and may be important for the acquisition of language in childhood.
Left angular gyrus
JJ dejerine
Written comprehension
Legions here cause inability to read and write
Able to speak and comprehend
Wernicke-Geschwind model
Geschwind:
Integrated the ideas of Broca, Wernicke and Dejerine into a omplete model of language processing
Involves seven components, all of which are in the left hemisphere
Auditory cortex - wernicke’s area for comprehension - brocas areas via arcuate fasciculus - motor cortex for response
Over simplistic
Current status of the wernicke-geschwind model
- Empirical evidence supports two elements
- Important roles played brocas and wernicke’s. Many aphasic have damage in these areas
- anterior damage associated with expressive deficits and posterior with receptive
- No support for more specific predictions
- Brain damage in other areas can produce asphasia
- damage limited to speciific areas does not produce permanent aphasia
