Lecture 18 Flashcards
What kind of function is verbal behaviour?
Laterialized
Where do most language disturbance occur after damage to where?
Regardless of what?
To the left side of brain.
Regardless if people are left handed or right handed
What is left hemisphere dominant for?
In how much of the population?
Speech for 90 percent of the population
How much is right hemisphere dominance in right handed people and left handed people?
4 percent of right handed people
27 percent of left handed people
What does pitch of the human voice indicate?
What does it distinguish?
It indicates phrasing
It distinguish between assertions and questions
How do humans impart information about their emotional state?
Through the prosody of their speech
What is prosody?
Rhythm, emphasis and tone of their speech
What is prosody typically a function of?
What does this mean?
The right hemisphere.
People with left hemisphere damage will still be able to appreciate prosody and extract information from it
What is recognition of a particular voice independant of?
Words and their meanings
What can people with left hemisphere damage who might not be able to understand words still recognize?
Voices
What is the disorder where people have difficulty recognizing voices?
What is it a result of?
Phonagnosia
Localized brain damage to the right superior temporal cortex
What does a task that requires comprehension of metaphors activates what?
The right superior temporal cortex
What does judging the moral of Aesop’s fable as opposed to judging more superficial aspects of the stories activate?
Regions of the right hemisphere
What does aphasia refer to?
A disturbance in understanding, repeating, or producing meaningful speech
What must happen in order to someone to have an aphasia?
The difficulty must not be caused by simple sensory or motor deficits or lack of motivation
The deficit must be relatively isolated: the patient must be capable of recognizing when others are attempting to communicate
The patient must be somewhere aware of what is happening around them
What happens when there’s damage to the frontal lobe?
It causes deficits in speaking
What are aphasias in the frontal lobe?
anterior aphasia
motor aphasia
expressive aphasia
broca’s aphasia
non fluent aphasia
what does damage to the sensory association cortex cause?
deficits in understanding language
What are aphasia’s in the sensory association cortex?
posterior aphasia
sensory aphasia
receptive aphasia
wernicke’s aphasia
fluent aphasia
What are the steps to “really” understand what a word means?
Vision: what does it look like?
Auditory: what do they sound like?
Touch: what do they feel like?
Olfaction: what does it smell like?
Gustatory: what do they taste like?
Motor: What do they act like? What does touching entail?
What is the posterior language area critical for?
Language comprehension
What happens in the posterior language area?
Give an example.
Neurons activate the ensemble of neurons through sensory association cortices that store the representations (meanings) of specific words.
Activating the DOG neurons would cause activity through sesnory association cortices (vision, hearing, touch, smell, taste and even motor commands like petting) that are associated with the word DOG
Where is the posterior language area?
The junction of the temporal, occipital and parietal lobes, around the posterior end of the lateral fissure
What is the posterior language area critical for?
Language comprehension
What does damage to the posterior language area cause?
Transcortical sensory aphasia
What is transcortical sensory aphasia?
A failure to comprehend the meaning of words and an inability to express thoughts with meaningful speech
What is possible in transcortical sensory aphasia?
Word repetition
Reading
Writing
What is conduction aphasia?
It is characterized by an inability to repeat the exact words you hear.
What is fine with conduction aphasia?
Speech : meaningful, fluid speech and good speech comprehension
What is an example of conduction aphasia?
When asked to repeat a word like house, they’ll say home
What is conduction aphasia a result of?
Damage to the connection between wernicke’s area and broca’s area, known as arcuate fasciculus
What does a direct connection between Wernicke’s area and Broca’a area enable patients with transcortical sensory aphasia?
It enables patients to repeat words that they cannot understand
What pathway is Broca’s area associated with?
a pathway that is associated with conduction aphasia
How is conduction aphasia charcterized?
Inability to repeat words that are heard
What is fine in conduction aphasia?
The ability to comprehend speech and speak normally
What causes conduction aphasia?
Damage to and around the arcuate fasciculus, a bundle of axons that connects Wernicke’s area with Broca’s area
What is wernicke’s area involved with?
Analysis of speech sounds and in recognition of spoken words
What is affected when the primary auditory cortex is injured?
Being able to hear
What is affected when there’s an injury in Wernicke’s area?
Recognizing words
What is associated with the posterior language area?
Understanding the meaning of words
What does the posterior language area overlap with?
Wernicke’s area
What is pure word deafness?
A disorder of auditory word recognition,
Inability to comprehend or repeat spoken words
What causes pure word deafness?
Damage to wernicke’s area or disruption of auditory input to this region
What can people with pure word deafness do?
Hear just fine
Interpret non speech sounds
Read and write
Read lips
Speak intelligently
What CAN’T people do if they have pure word deafness?
They can’t recognize the words they are saying by listening to themselves
What is the result of damage to Wernicke’s area AND to the posterior language are?
What does this mean?
Wernicke’s aphasia
You have features of transcortical sensory aphasia AND pure word deafness
What is the defining feature of Wernicke’s aphasia and transcortical sensory aphasia?
Poor language comprehension
What can people with poor language comprehension do?
They can have fluent speech production
What do people with poor language comprehension do?
What they say is meaningless
They talk with a lot of function words (a, the, about)
They talk with a lot of intonation and emphasis
Are people with poor language comprehension aware of their problem?
No
What has poor language comprehension been characterized as?
Receptive or fluent aphasia
What do people with transcortical sensory aphasia have trouble with?
Language comprehension BUT they can recognize spoken words
What’s the difference between transcortical sensory aphasia and wernicke’s aphasia?
TSA: can repeat what other ppl say to them
WA: cant’t
What are transcortical sensory aphasia and wernicke’s aphasia associated with?
Damage in and around wernicke’s area
Would you be able to differentiate between Wernicke’s aphasia and transcortical sensory aphasia just be looking at a brain scan?
No
What is the result of damange to the visual word form area?
It disrupts the ability to perceive written words
Where is the visual word form area?
Fusiform gyrus of the left hemisphere
What happens when you damage the the visual word form area?
What’s this called?
What can they still do?
They cannot read
Pure Alexia or Pure Word blindness
Write
What is dyslexia?
“faulty reading”, they have difficulty reading
What processes does reading involve?
Direct recognition of the word as a whole and sounding it out letter by letter
What’s whole word reading?
Reading by recognizing a word as a whole; “sight reading”
What’s phonetic reading?
Reading by decoding the phonetic significance of letter stings. “sound reading”
What is surface dyslexia?
What does it mean?
What is difficult for person? Why?
An inability to recognize whole words.
The person can only read words phonetically.
Irregularly spelled words are difficult
What is phonological dyslexia?
Reading disorder in which a person can read familar words but has difficulty reading unfamiliar words or non words
What is developmental dyslexia mostly?
Phonological dyslexia, largely genetic
What do people with developmental dyslexia have difficulty with?
Reading, some never become fluent and grammar and spelling, distinguishing the order of sound sequences
What is direct dyslexia?
What’s it from?
Not able to extract meanings from words despite being able to read out loud.
Stroke
What are the most important cues to object recognition?
Those that remain relatively constant, even when objects are viewed from different angles
What happens when there’s damage to Broca’s area in the left inferior frontal lobe?
Broca’s aphasia : Makes it difficult for patients to express themselves verbally
What is broca’s aphasia chracterized by?
Slow, laborius and non fluent speech
Are people with broca’s aphasia aware of their condition?
Yes and very frustrated with it
What are the three semi distinct issues that encompasses Broca’s aphasia?
Articulation problems
Agrammatism
Anomia
What’s articulation?
Movement of tongue, lips, jaw, and other speech organs to make speech sound
What’s aggramatism?
Difficulty comprehending or using grammatical devices
What do people with aggramatism typically do?
Do not derive meaning from the sequence of words
They almost exclusively use content words without any function
What’s a content word?
Noun, verb, adjective or adverb that conveys meaning
What’s a function word?
A prepositio,article or other word that conveys little meaning but is important for grammatical structure of a sentence
What’s anomia?
Difficulty in finding the appropiate word to describe object, action, or atrribute; one of symptoms of broca’aphasia
What do people with Anomic aphasia have a hard time with?
Thinking of the word they want to say
What do people with anomic aphasia have no trouble with?
Understanding what other people say, they talk just fine
What do people with anomic aphasia do?
Describe things in a roundabout ways (circumlocution)
What’s circomlocution?
Strategy by which people with anomia find alternative ways to say something when they are unable to think of most appropiate word
What are subvocal articulations?
Ex: when we talk about ourselves in our head, there is often subvocal articulations ( slight movements of muscles involved in speech that do not actually cause obvious movement)
What is stuttering?
A speech disorder characterized by frequent pauses, prolongations of sounds, syllabeles, or words that disrupt the normal flow of speech
What does stuttering appear to be a problem of?
Selecting, initiating and executing the motor sequences required for fluent speech
What does stuteering appear to be influenced by?
Genetic factors
How much of the world is affected by stuttering? How many more times men than in woman?
1 percent of population, 3 times more prevalent in men than in woman
What is the neural basis of stuttering?
Unknown
What have we discovered in the brains of people who stutter?
Many studies have revealed irregularities in timing of neural activity in different areas if the brain
What have human fMRI studies comparing brain activity in people who do or don’t stutter when speaking found?
Small differences in the amount of activity and the timing of activity across left and right cerebral hemispheres across frontal and temporal lobes, primairly in Broca’s area, Wernicke’s area and primary motor cortex
What does writing depend on knowing?
The words you want to use
Proper Grammatical structure
Specific motor commands that control the hand
What is trouble with writing called?
Dysgraphia
Can their be specifc deficits in motor programs?
yes
How can spelling a word be accomplished by?
Phonetically sounding out a word and visually imagining the word
What is phonological dysgraphia?
Condition where people cannot spell words by sounding them out
What is orthographic dysgraphia?
Condition where people cannot spell words by visualizing them
