4 Language and the Brain Flashcards
What’s language?
Unique + universal human attribute.
spoken, written, signed forms.
How is language produced?
Larynx has vocal cords, as air moves through they contract + relax to produce vibrations. At rest = relax.
what are the types of sounds?
dental frictative - th, labiodental frictative - f,v.
when did language evolve?
descent of larynx - 100-200k yrs ago.
chimps - larynx higher up.
FOXP2 divergence happened around 200k yrs ago (also present in neanderthal - may have spoke, but less sophisticated).
Symbolic behaviour - 60k yrs ago.
Tower of Babel - religious exp.
Phonemes?
Phonotactic rules?
Morphemes?
Syntax?
Prosody?
basic sounds.
how phonemes can be combined.
structural units of language that indicate meaning.
word order.
patterns of stress + intonation.
What did Kuhl 2004 find?
between 1 + 5 and 5 + 12 - lose ability to learn a language as easily.
Broca - describe case study of Tan?
Loss of speech, not comprehension.
Lesion in left FC.
Similar results in 12 more.
Wernicke 1874? Aphasic syndrome?
fluent speech, lack of comprehension.
left superior temporal gyrus - wernicke’s area.
Receptive/ Wernicke’s aphasia.
usually more damage than to just this area.
mild impairment of ability to perceive phonemes.
What do the sign language versions of both aphasia involve?
In broca, ability to move hands is impaired in context of language, but no other tasks = not pure motor problem.
What are wada procedures?
injection of anaesthetic into carotid artery. anesthetises 1 side of brain.
What did wada procedures show about hemispherectomy?
right handed people = speech rep mostly in LH.
left = speech rep mostly in LH, remainder split equally between right + bilateral.
What did Wernicke-Geschwind model suggest?
what are problems w/ it?
produces speech on right, comprehension on left.
ignores that they’re separate + wernicke’s area more spread out.
Now obsolete.
What’s the more modern model for language?
dual stream - Hickok + Poeppel.
Describe dual stream model?
Dorsal stream concerned w/ producing speech, ventral is concerned w/ comprehension.
Ventral partly bilateral/
What does the dual stream model say is the language functions of each hemisphere?
LH = speech production, some aspects of comprehension - literal meanings, syntax, grammar.
RH = some aspects of comprehension - prosody, ambiguous, social comm. more recruited in sign language.
