Lecture 18: Language Flashcards
what causes most language disturbances?
damage to the left side of the brain
which brain hemisphere is dominant for speech?
left
is right hemisphere speech dominance possible?
yes! it’s seen in 4% of right-handed people and 27% of left-handed people
prosody
Includes rhythm, emphasis, and tone of human speech
what hemisphere is responsible for prosody?
right
what controls the recognition of people’s voices?
right hemisphere
Phonagnosia
a disorder where people have difficulty recognizing voices and become literal in their interpretation of language
cause of phonagnosia
localized brain damage to the right superior temporal cortex
what part of the brain is needed for the comprehension of metaphors?
the right superior temporal cortex
aphasia
A disturbance in understanding, repeating, or producing meaningful speech
what happens when there is damage to the frontal lobe
deficits in speaking
what happens when there is damage to the sensory association cortex?
deficits in understanding language
Premotor cortex
located in the frontal lobe. responsible for motor comprehension
auditory association cortex
located in the temporal lobe. responsible for auditory comprenhension
visual association cortex
located in the occipital lobe. responsible for visual comprehension.
somatosensory association cortex
located in the parietal lobe. responsible for touch comprehension
broca’s area
located in the frontal lobe. responsible for speaking
posterior language area
critical for language comprehension
how do neurons in the posterior language cortex result in language comprehension?
Neurons here activate the ensemble of neurons throughout sensory association cortices that store the representations (the meanings) of specific words.
where is the posterior language area located?
at the junction of the temporal, occipital, and parietal lobes around the posterior end of the lateral fissure
types of frontal lobe damage aphasias
anterior, motor, expressive, broca’s, and non-fluent aphasia
types of sensory association cortex damage aphasias
posterior, sensory, receptive, Wernicke’s and fluent aphasia
transcortical sensory aphasia
Failure to comprehend the meaning of words and an inability to express thoughts with meaningful speech
what causes transcortical sensory aphasia?
damage to the posterior language area (back of the brain)
all language perception areas connect to what brain area
the posterior language area & Bronca’s area
conduction aphasia
Characterized by an inability to repeat the exact words you hear
what causes conduction aphasia?
Result of damage to the connection between Wernicke’s area and Broca’s area known as the arcuate fasciculus
arcuate fasciculus
A direct connection between Wernicke’s area and Broca’s area enables patients with transcortical sensory aphasia to repeat words they cannot understand
Wernicke’s area function
Involved in the analysis of speech sounds and in the recognition of spoken words
Wernicke’s area location
Region of the auditory association cortex (superior temporal gyrus) on the left temporal lobe
pure word deafness
An inability to comprehend or repeat spoken words
pure word deafness cause
damage to a small part of Wernicke’s area
wernicke’s aphasia
features of transcortical sensory aphasia and pure word deafness. People have poor language comprehension and what they say is meaningless and typically filled with function words
are people with wenicke’s aphasia aware of their condition?
no, they are unaware
difference b/n transcortical sensory aphasia an wernicke’s aphasia
Patients with transcortical sensory aphasia can repeat what other people say to them & recognize spoken words, but patients with Wernicke’s aphasia have trouble with learning comprehension and are generally not capable of repeating what other people say to them
visual word form area function
Responsible for written word perception
visual form area location
the fusiform gyrus of the left hemisphere
where is face perception dominant
in the right hemisphere fusiform gyrus
pure alexia
Inability to perceive written words
pure alexia cause
damage to the visual word-form area (VMFRA)
can people with pure alexia write?
yes, they just can’t read what they’ve written
dyslexia
difficulty reading
reading
involves at least two different processes: direct recognition of the word as a whole and sounding it out letter by letter
whole-word reading
reading by recognizing a word as a whole (sight reading)
steps of whole-word reading
The sight of word -> whole-word recognition -> control of speech
phonetic reading
reading by decoding the phonetic significance of letter strings (sound reading)
steps of phonetic reading
The sight of word -> letter recognition -> phonetic coding -> control of speech
surface dyslexia
an inability to recognize whole words. The person can only read words phonetically
phonological dyslexia
reading disorder in which the person can read familiar words but has difficulty reading unfamiliar words or nonwords
developmental dyslexia
a largely genetic form of phonological dyslexia where people have great difficulty learning to read and some never become fluent readers even though they are otherwise intelligent
direct dyslexia
can read out loud without understanding what they’re reading
direct dyslexia cause
a stroke in the back half of the brain
broca’s aphasia
Characterized by slow, laborious, and nonfluent speech
broca’s aphasia cause
Results from damage to Broca’s area in the left inferior frontal lobe
are people with broca’s aphasia aware of their condition?
yes, they are aware of it and frustrated by it
what type of words do people with broca’s aphasia mainly use?
content words
three main issue associated with broca’s aphasia
articulation problems. agrammatism, and anomia
articulation problems
Movement of tongue, lips, jaw, and other speech organs to make speech sounds.
agrammatism
Difficulty comprehending or using grammatical devices, such as verb endings
anomia
Difficulty in finding (remembering) the appropriate word to describe an object, action, or attribute
content word
Noun, verb, adjective, or adverb that conveys meaning.
function word
Preposition, article, or another word that conveys little meaning but is important for the grammatical structure of a sentence
anomic aphasia
Characterized by having a hard time thinking of the word they want to say. They can understand what other people say just fine, but describe things using circumlocution
circumlocution
A strategy by which people with anomia find alternative ways to say something when they are unable to think of the most appropriate word
fluency comprehension & repetition of global aphasia
patient isn’t fluent, can’t comprehend, and can’t repeat
fluency comprehension & repetition of Broca’s aphasia
patient isn’t fluent, can comprehend, but can’t repeat
fluency comprehension & repetition of Wernicke’s aphasia
patient is fluent, can’t comprehend, can’t repeat
fluency comprehension & repetition of conduction aphasia
patient is fluent, can comprehend, but can’t repeat
fluency comprehension & repetition of anomic aphasia
patient is fluent, can comprehend, and can repeat
what happens if pure alexia patients only have damage to the left primary visual cortex
they are right visual field blind, can’t see anything to the right of the fixation point, but can read
what happens if pure alexia patients have additional damage to the corpus callosum?
they are right visual field blind, can’t see anything to the right of the fixation point, but can’t read
acquired dyslexia
caused by damage to the brains of people who already know how to read
fluency comprehension & repetition of transcortical sensory aphasia
is fluent, can’t comprehend, can repeat
