Language Flashcards
Define language
Is a system for representing and communicating information that uses words combined according to grammatical rules
Define speech
An audible form of communication built on the sounds humans produce.
What are phonemes?
Fundamental sounds that a language uses to communicate
What is language acquisition?
Learning a language
How do children learn the the combination of sounds?
Possible locations of word boundary
Syllable emphasis
How does listening to speech affect the brain?
Activates extensive areas in the temporal lobe with activation strongly biased toward the left hemisphere.
Define verbal dyspraxia
An inability to produce the coordinated muscular movements needed for speech
What genes underlie verbal dyspraxia?
FOXP2 - a transcription factor responsible for turning other genes off and on,
What is specific language impairment?
Consists of a developmental delay in the mastery of language that may persist into adulthood and is not associated with hearing difficulty or more general developmental delays
What genes are involved with SLI?
FOXP2
CNTNAP2 - neurexin protein
KIAA0319
What role does CNTNAP2 play in the brain?
Proteins on the presynaptic side of synapses that serve to hold the presynaptic and postsynaptic events together.
Brain development by properly locating potassium channels in the developing neurons.
What is the role of KIAA0319 in the brain?
Neuronal migration during neocortical development
Define dyslexia
Difficulty learning to read despite normal intelligence and training,
What gene is involved with dyslexia?
KIAA0319
Define aphasia
Partial or complete loss of language abilities following brain damage, often without the loss of cognitive faculties or the ability to move muscles used in speech
Define Broca’s aphasia
A language disturbance in which a person has difficulty speaking or repeating words but can understand language
Where is Broca’s area located?
Left frontal lobe
Where is wernickes area located?
Superior surface of the temporal lobe between the auditory cortex and the angular GYRUS
Define anomia
Inability to find words
Define agrammatism
Inability to construct grammatically correct sentences
Define paraphasic errors
Substitute incorrect sounds or words
What are the characteristics of Broca’s aphasia?
Anomia
Content words (nouns, verbs and adjectives carrying content specific to the sentence) is used but function words (articles, pronouns and conjunctions) are left out
Agrammatism
Paraphasic errors
Define wernickes aphasia
Speech is fluent but comprehension is poor
Define Wernicke-Geschwind model
A model for language processing involving interactions of Broca’s area and Wernicke’s area with sensory and motor areas
What brain areas are involved in Wernickes-Geschwind model
Broca’s
Wernickes
Arcuate fasciculus - a bundle of axons connecting the two cortical areas
Angular GYRUS
Describe the pathway involved in repeating a spoken word
Sound - auditory cortex - wernickes area (meaning found) - arcuate fasciculus - Broca’s area (coding for muscle movement) - motor cortex
Describe the pathway involved in repeating aloud a written word
Reading - primary visual cortex - angular GYRUS - wernickes - Broca’s - motor cortex
What are several errors with the Wernicke-Geschwind model?
- Visual information can be processed in other areas which bypass the angular GYRUS
- Aphasia also due to damage to thalamus which is not shown in model
- Language improvements after stroke. Other brain regions can compensate for lost areas
Define conduction aphasia
A type of aphasia associated with damage to the arcuate fasciculus, characterised by good comprehension and speech but difficulty repeating words
What happens to a bilingual person suffers from a stroke
Not predictable but the language learned more fluently and earlier in life tends to be relatively more preserved
Similar effect to both languages if learned at the same time
Define split brain studies
Hemispheres are surgically disconnected
Describe the affects of left hemisphere language dominance in split brains
Repeat words, describe numbers, words and pictures casually present on the right visual field.
Describe the objects being manipulated in only the right hand.
Unable to describe anything to the left of the visual fixation point
What affects the language functions of the right hemisphere in split brains?
Read and understand numbers, letters and short words as long as no verbal response was required
What is the right hemisphere usually dominant in?
Comprehending languages,
What is an anatomical difference in the two hemispheres
Left Sylvian fissure is longer and less steep than the right,
What areas are larger on the left between the two hemispheres?
PLANUM Temporal
Broca’s area
Insula
Which brain region is the best predictor for language dominance?
Insula
What did stimulation of the motor cortex in the area that controls the mouth and lips
Immediate speech arrest
In other motor cortex areas, evoked cries or rhythmic vocalisation.
What sites resulted in word confusion and speech arrest after stimulation?
Posterior lobe near the Sylvian fissure
Temporal lobe
In the vicinity of the arcuate fasciculus and wernickes area.
What conclusions have been made from stimulation of the cerebral cortex?
- There is a considerable variability in areas stimulated that affects language.
- Areas between known language regions do not affect language,
- Stimulation at nearby site ps can evoke different effects but far away areas evoke same effect
