speech and language Flashcards
what is language + what used for (2)
arbitrary symbols with specific meanings to (a) refer to the outside world, and (b) express ideas, feelings, desires and emotions
is the brain hardwired for language
- seem to be born with circuits prepared for oral language
- written language is learned and recycles some of the preexisting circuits (of oral language)
brain area linking sounds and meanings
left temporal and parietal -> wernicke’s area
brain area organizing production of meaningful speech through motor commands
left frontal -> broca’s area
brain area responsible for emotional content of speech
right hemisphere
elements needed to produce written and oral language (3)
- motor control of speech production
- auditory and visual perception
levels of language (5)
- phonetics -> set of unitary sounds used to form symbols (phonemes)
- grammar -> rules for use of symbol
- syntax -> ordering of symbols to create meaning
- semantics -> associating symbols with meaning
- prosody -> emotional valence by varying intensity, pitch, rhythm
timeline of language development (5)
- 1st year (universalists) -> sensitive to phonemes; can discern slight acoustic changes
- start imitating sounds around 20 wks
- 6 months -> phonetic prototypes
- after 1y -> neural commitment to mother tongue (formation of speech-motor patterns)
- 3y -> ~1000 words, sentences, conversation
when does capacity to distinguish phonemes decline
before onset of first words (by end of 1st year)
period of best acquisition of 2nd language
<7 years
definition of critical period for language + ex of critical periods
moment when brain is plastic for learning (extended neural modification supporting behavior) -> 2nd half of 1st year (phonetic learning); first 7 years (language acquisition)
what does language acquisition depend on (2)
- experience
- time
area next to broca’s area + what does it do
primary motor cortex -> moves phonatory muscles
area next to wernicke’s area + what does it do
primary auditory cortex -> processes auditory input
what connects broca and wernicke’s areas
arcuate fasciculus
brain area involved in word meaning
temporal lobe
effect of lesion to any language area
aphasia
broca’s aphasia (7)
- affects ability to produce language efficiently
- nonfluent, effortful language
- preserved comprehension
- impaired repetition
- deficiency in motor planning
- disrupted organizational aspects of language
- sometimes right hemiparesis
other names for (a) broca’s aphasia (b) wernicke’s aphasia
(a) motor or expressive aphasia
(b) sensory or receptive aphasia
wernicke’s aphasia (5)
- affects ability to understand spoken language (impaired comprehension)
- fluent, well articulated/structured
- abundant, but non-sensical speech
- repetition impaired
- difficulty putting together objects or ideas with meaning
aphasias (7)
- broca’s
- wernicke’s
- conduction aphasia
- alexia
- agraphia
- dysarthria
- hypergraphia
brain area activated by written language
left vwfa
what does written language involve
production and interpretation of visual symbols
activity in vwfa in dyslexic people
decreased activity in vwfa
dyslexia
learning disorder involving difficulty reading due to problems identifying speech sounds and learning how they relate to letters and words
intelligence of dyslexic people
normal or above normal
problems that can occur with/because of dyslexia (2)
writing and spelling (errors of transposition)
what allowed assessing the function of the left and right hemis separately
severing of anterior commissure and cc (split brain patients)
what did split brain patients confirm
language is lateralized
split brain patients: wo visual cues, identify object in (a) right hand, (b) left hand
(a) easily name object in right hand
(b) fail to produce verbal account or only produce indirect description
split brain patients: show word or object in (a) LVF (b) RVF
(a) cannot read word or identify object
(b) can read word and identify object
brain area where sign language functions in congenitally deaf people
similar cortical areas (broca and wernicke) -> but specialized for symbolic representation and communication (instead of hearing and speech)
left hemi functions (5)
- analysis of RVF
- stereognosis (right hand)
- lexical and syntactic language
- writing
- speech
right hemi functions (5)
- analysis of LVF
- stereognosis (left hand)
- emotional coloring of language
- spatial abilities
- rudimentary speech
language deficits after right hemi damage
loss of normal rhythm, stress and tonal variation of speech (prosody)
brain areas affected in aprosodias
broca and wernicke areas in right hemi
wada test
short-acting anesthetic injected into left carotid artery to transiently anesthetize left hemi -> if left dominant for language, patient becomes transiently aphasic
less invasive tests of hemispheric lateralization (4)
- pet
- fmri
- tms
- tachistoscopic stimulus presentations
why does focal damage to temporal lobe sometimes lead to deficits for specific categories of objects
because distinct regions of temporal cortex are activated by language tasks involving specific categories
ways aspects of language can be organized (2)
- categories of meaning
- individual words
semantic categories depend on
features of word -> motor, sensory, abstract
features of concrete words depend on
experience when learning the word - overlap bw conceptual and perceptual systems
embodied semantics
way store memory linked to sensory processing (and experience?)
congenitally deaf patients with lesions to (a) right hemi (b) left hemi (broca’s and wernicke’s)
(a) deficits in emotional tone of signing
(b) deficits in sign production and understanding
how is the way songbirds learn songs similar to the way humans learn language (4)
- sensory acquisition through tutor
- vocal learning through practicing
- acoustically stable (crystallized song)
- regional dialects
how can animals communicate
ability to associate specific meanings with arbitrary symbols
how is human communication similar to animal communication
inherent and acquired neural associations bw tokens and meanings of other animal communication
