Language Flashcards
Aphasia
Language deficit
Lesion in an area involved with language
Hemisphere mainly involved in language =
Left
Kanzi the bonobo
Savage-Rumbaugh (1986)
Pigmy chimp - learned to communicate with pictures.
But believed to be stimulus response pairing - no complex communication, only asking for food, water, etc. (conditioning).
Auditory theory
Speech signal is compared against a stored repertoire of auditory representations (words).
Decipher the meaning of the auditory information from previous exposure to same sounds (top-down, use contextual info).
Motor theory
Auditory signal is matched with own internal speech motor programme.
Lateralisation definition
The function of the same area in the two hemispheres are different - specialisation of function in one side.
Prevents redundancy - wasting resources.
Type of aphasia - Tan
Broca’s aphasia
Only able to say word TAN
Wada procedure
Anaesthetic injected into carotid artery (sodium amobarbitol).
Enters cerebral cortex on ipsilateral side. Can test the effects on language (temporary) - see which side of brain is dominant in language.
Normally left in RH people, but can be on right in LH people or bilateral.
Broca’s area
Anterior to wernicke’s area.
Involved in language production.
Lesions to Broca’s area produce deficits in speech production.
Frontal lobes.
Wernicke’s area
Posterior to broca’s area.
Involved in language comprehension.
Lesions to Wernicke’s area cause incomprehensible speech.
Auditory cortex
A1 - Heschl's gyrus. Tonotopcally organised (sensitive to temporal changes). Respond to speech sounds LH - comprehensible RH - incomprehensible, melodical.
Expressive aphasia
AKA Broca’s aphasia
Slow speech
Difficulty with speech
No function words, e.g. a, the, my.
Only content words, e.g. nouns, adjectives, verbs.
Some effect on comprehension (agrammatisation).
Aware of own deficit.
Agrammatisation
What area is thought to be damaged in agrammatisation?
Difficulty using grammar structures.
Can have difficulties understanding ambiguous statements. e.g. the cat licked the dog.
Able to understand if meaning is clear
Damage to the inferior frontal lobes.
Articulation
What area is thought to be damaged in articulation?
Difficulty in pronunciation of word, and sometimes changing the order of sounds in words.
Damage to the insula cortex.
Anomia
What area is thought to be damaged in anomia?
Difficulty in finding the appropriate word to use - words are used inappropriately.
Damage to the inferior frontal lobes.
Speech apraxia
Difficulty in speech motor production. Often involving damage to the inferior frontal lobes.
Wernicke’s aphasia
Problem with comprehension of words and production of content words.
Normal speech flow
Contains function words, e.g. a, the, my.
Poor comprehension of speech.
Appear unaware of deficit.
Both transcortical sensory aphasia and word deafness.
Word deafness
Inability to recognise speech sounds.
Deficit in perception/processing.
Not deaf, as can recognise other sounds, e.g. dog barking
suggesting that a very specific area of the brain is responsible for hearing speech, as opposed to other sound signals.
No deficit in comprehension of speech - understands lip reading, and communicated through writing.
Deficit in aud. input to W area.
Transcortical sensory aphasia
Repeats spoken words, can hear.
Unable to understand heard or repeated words.
Unable to produce own meaningful speech.
Still have auditory input to W area, can still recognise speech sounds.
Type of aphasia that suggests that there is direct link between Broca’s and Wernicke’s ares.
Transcorical sensory aphasia (TSA).
Able to recognise speech sounds but unable to comprehend them.
Area linking Broca’s —> Wernicke’s areas.
Post language area
Lesion to Post lang area = loss of meaning and production of speech.
Area linking Wernicke’s —> Broca’s area.
Arcuate fasciculus.
Conveys sounds of words but not their meaning.
Conduction aphasia
Damage to arcuate fasciculus.
Cannot repeat words that they do not recognise
W and A areas are still connected via posterior lang area. - must have meaning already stored.
Ventral route
What pathway (auditory)
Dorsal route
Where/how pathway (motor)
Parietal –> frontal lobes.
Proposed homologue for Wernicke’s area in rodents
DF area
If damaged, unable to communicate via ultrasonic signalling (bonding).
Side of brain in bilingual people involved in 1st language/2nd language
Right/Left (left more difficult language).
In split-brain patients, which hemisphere will an image shown to the R visual field be processed in?
Left hemisphere
In split-brain patients, which hemisphere will an image shown to the L visual field be processed in?
Right hemisphere
If shown to left visual field, will be able to say/touch key?
Touch and say key
If shown to right visual field, will be able to say/touch key?
Touch key only
Which hemisphere controls writing?
Both - even if Left or right handed.
Patient JW
Split brain patient.
Unable to integrate compound words, e.g. head-stone. Does not provide the emergent word.
Hemisphere more involved in visual memory?
What test can we use to test this?
Right hemisphere
Corpus callostomy, eg JW, LH mistakenly identifies more within-scene distractors as seen than the RH.
Location of possible neural audio dictionary =
Wernicke’s area
Recognition of speech sounds - known or not known?
