Chapter 20: Language Flashcards
Language is universal in () (no mute tribe has ever been found)
human society
The universality of language suggests that the human brain has evolved special ().
language-processing systems
before the rise of brain imaging techniques, most knowledge on brain mechanisms of language was obtained from ()
brain-damage patients
What is Language
A system for representing and communicating
(1); uses words combined according to (2)
- information
- grammatical rules (Chomsky: universal grammar)
An audible form of communication built on the sounds
humans produce
speech
features of human language
- discreteness
- productivity
- grammar
- displacement
- modality independent
(): Linguistic representations can be broken down into small discrete units (e.g., sentences are built up of discrete words).
Discreteness
(): we are able to produce an infinite number of ideas using a limited set of words.
productivity
Grammar: Languages employ (1) categories, such as noun and verb, present and past, which may be used to express exceedingly complex meanings; (): a clause can contain another clause (as in “[I see [the dog is running]]”)
- grammatical and semantic
- recursivity
(): humans can talk about things that are not physically present or that do not even exist.
Displacement
Modality independent: ()
spoken language, writing, braille
a set of features that characterize human language and set it apart from animal communication
Hockett’s design features
Hockett’s Design Features
(): while humans are born with innate language capabilities, language is more learned after birth through a social setting.
Traditional (cultural) transmission
explain the idea that speech comes naturally to humans
a child picks up spoken language from his environment even without formal training
Human Language:
- Complex, flexible, powerful (1) for communication
- Creative use of words according to (2)
- system
- rules
Speech and language disorders run in (1), more likely to co-occur in (2)
- families
- identical twins
inability to produce clear speech
verbal dyspraxia
Study of KE family (verbal dyspraxia)
- found that affected famly members had (1) mutation
- affected development of structures like: (2)
- also had deficits in (3)
- FOXP2 (transcription factor) single mutation
- motor cortex, cerebellum, striatum
- grammatical skills and muscular control of lower face
() strongly expressed in brain areas involved in song learning in birds; A small and relatively recent mutation in the gene may have set humans on a path toward developing language that was needed for higher cognitive function and the development of human culture
FOXP2
Developmental delay in mastery of language,
especially verbs; not associated with hearing difficulty or more general developmental delays
specific language impairment (SLI)
aside from FOXP2, mutations in () are also thought to be involved in SLI
CNTNAP2, KIAA0319
() codes a neurexin protein; plays an important role in brain development
neurexin - proteins on presynaptic terminals; serve to hold presynaptic and postsynaptic elements together
CNTNAP2
() is thought to be critical for neuronal migration during neocortical development as well as for normal function of adult neurons
KIAA0319
() - trouble with reading despite normal intelligence; appears to have strong genetic link; 5-10% of population; 40-50% comorbidity with SLI
Dyslexia
Partial/complete loss of language abilities following
brain damage; often without the loss of cognitive faculties or ability to move speech muscles
aphasia
Greek/Roman Empires: () thought to control speech
tongue
(): region of dominant left frontal lobe, articulate speech
Broca’s area
(): superior surface of temporal lobe between auditory cortex and angular gyrus, lesions disrupt normal speech; proposed a language processing map
Wernicke’s area
Used to determine hemisphere dominant for speech; anesthetizing only 1 hemisphere
Wada procedure
anesthesia to left hemisphere (not right) always led to speech impairment
Distinct types of aphasia suggest language is processed in ()
several stages at different brain areas
(): Damage in motor association cortex of frontal lobe; comprehension generally good, but trouble in understanding complex sentences
Broca’s Aphasia
inability to find words (need to pause to find right word)
anomia
explanation of Broca’s aphasia symtoms
Wernicke: Broca’s area contains (); makes sense considering Broca’s area is near the part of the motor cortex controlling the mouth and lips.
memories for the fine series of motor commands required for articulating word sounds
describe
“telegraphic style” of speech
mostly content words, no function words -> only nounds and verbs
explanation of Broca’s aphasia symtoms
Alternative: Broca’s area may be specifically involved in making (); makes sense considering the difference in the aphasic’s ability to use content words and function words
grammatical sentences out of words
(): Posterior temporal lobe damage; fluent speech but poor comprehension
Wernicke’s aphasia
explanation of Wernicke’s aphasia symptoms
Wernicke’s area is located near A1; may () -> in Wernicke’s aphasia, speech production system may operate without control over content
relate incoming sounds to their meaning (storing memories of sounds that make up words).
components of the Wernicke-Geschwind Model
model for language processing in the brain; offers simple explanations for key elements of Broca’s nd Wernicke’s aphasias
- Broca’s Area
- Wernicke’s Area
- arcuate fasciculus
- angular gyrus
Wernicke-Geschwind Model
W -> B connection
arcuate fasciculus
Wernicke-Geschwind Model
visual to auditory transformation
angular gyrus
- Numerous more elaborate language models have been proposed
- Current models of language processing emphasize multiple
streams of processing
parallel language pathways
(): Disconnection lesion of arcuate fasciculus and parietal cortex; difficulty repeating words but comprehesion and speech are good
conduction aphasia
inequal effects of aphasia in bilinguals (varying fluency in L1 vs L2) implies:
L2 uses different, although overlapping neuron populations used by L1
in split brain studies, behavior (1) but animals acted as if (2)
- largely unchanged
- had 2 brains
effects of aphasia in deaf ppl/ppl who can use sign language imply:
some universality to language processing in the brain
because it didn’t seem to be important, surgeons felt they were justified in cutting the corpus callosum as a last resort in treating ()
epilepsy
Gazzaniga’s exp: Brief stimuli delivered only to ()
one hemisphere.
if the left hemisphere is dominant for language, the right hemisphere is better at ()
spatial perception and emotional content of speech
Bradshaw & Nettleton (1981)
– (1) hemisphere: sequential, analytic, and time
dependent.
– (2) hemisphere: synthetic and holistic.
- Left
- Right
left vs right hemispheres
Instead of breakdown by type of task (verbal vs. spatial), may be better categorized as () (LH: analytic skills, with language just an example; RH: synthetic processing, so better at visuospatial tasks).
different ways of dealing with the information
most significant example of anatomical asymmetry between the 2 hemispheres; (part of Wernicke’s area) larger than right in 65% cases (the opposite cases: 10%)
found in human fetus and apes
planum temporale
(): the best predictor for language-dominant hemisphere
Insula
recent techniques for language studies (neurosci)
study language function in living humans with electrical brain stimulation and PET scans
Three main effects of brain stimulation on language
Vocalizations, speech arrest, speech difficulties
similar to aphasia
brain stimulation in (): immediate speech
arrest (occasionally vocalization)
motor cortex
brain stimulation in (): speech arrest from strong stimulation, speech hesitation from weak stimulation
Broca’s area
brain stimulation in (): word confusion and speech arrest
posterior parietal lobe near Sylvian fissure and in temporal lobe (vicinity of Wernicke’s area and arcuate fasciculus)
in brain stimulation language studies, areas affecting speech roughly correspond to ()
aphasia-related areas
Ojemann studies found that ()
stimulation effects can sometimes be quite specific
stimulation of different small cortical areas affect different aspects of language: naming, reading, repeating facial movements
