L12 - language

What are the 3 features of human language?

universal - all cultures have a language and development occurs similarly across cultures, generative - smaller components combine into bigger units, and rule based for syntax

What 2 pieces of evidence shows that language is largely lateralised?

language is lateralised to the left hemisphere for most people, the Wada test where an anaesthetic is injected into the internal carotid arteries temporarily affects one hemisphere resulting in loss of limb control and speech, and split brain patients: corpus callosum connection between hemispheres is severed, when word appears in RVF patients can name word but when in LVF patients cannot say word as can’t access language functions from LH but can draw it

What is the arcuate fasiciculus?

fibre connection between the Wernicke’s area and Broca’s area

What is Wernicke’s aphasia?

fluent effortless speech but impaired speech comprehension and repetition and often unaware of errors

What is transcortical sensory aphasia?

damage between Wernickes and region that assigns meaning, intact repetition but impaired speech comprehension

What is transcortical motor aphasia?

damage between region that assigns meaning and Brocas, intact repetition but difficulty finding words

What is conduction aphasia?

damage to the arcuate fasiciculus, intact comprehension but impaired repetition

What is Broca’s aphasia?

non-fluent effortful speech issues with speech production, impaired repetition

What is pure word deafness?

difficulties understanding speech but can read and understand speech, hear and describe other sounds

What is apraxia?

problem in speech programming muscles, can generate words to say but brain can’t command muscles to say them

What is dysarthria?

problem of control over speech muscles, commands to muscle are correct but muscles aren’t responding

What does the classic model fail to account for?

hierarchal structure of language

What is the dual stream model of language?

bilateral arrows to show bottom up and top down processing, analysis of tone and timing of sounds, break down of sounds, split into dorsal (how to say it, map sound to motor representation) and ventral stream (what was said, map sound to meaning)

What is the association between speech and the superior temporal gyrus?

particular neurons respond to particular aspects of speech e.g. high pitch, neurons with similar responses are clustered together in STG

What is the association between the right hemisphere and language and consider damage?

right hemisphere processes prosody: where the stress is put in a sentence changing its meaning, when the right STG is damaged associated with impaired identification of emotional prosody

What is mental lexicon?

knowledge of words, meanings, pronunciation, grammar, and related words

What is semantic dementia and what area is associated with it and why?

people forgot the meanings of uncommon words first then the meanings of common words later on, associated with damage to the anterior temporal lobe which is thought to be a ‘hub’ which links cortical regions