Cortex 2b Flashcards

Question

what is prosopagnosia?

Answer 1

difficulty in recognizing faces although vision is normal problem with inferiotemporal -- ventral stream

Answer 2

bilateral system- different fibers cross at different levels bipolar cells in spiral ganglion, go into either cochlear nuclei- from here on= bilateral major cross over occurs in trapezoid body then to dorsal or intermediate acoustic stria, superior olive in lower pons (subconscious picking out of location of sound, efferents to hairs to buffer sounds to up specific frequencies) --> up lateral lemniscus--> up to primary auditory cortex in superior temporal gyrus (areas 1, 41)

Answer 3

area 41 tonotopically arranged - anterior- lower sounds - posterior- higher sounds bilaterally innervated columnar organization based on frequency- depth of column is sensitized to each frequency

Answer 4

one side: | -loss of localization- of just that frequency

Answer 5

``` 1- Dorsal "where & how" stream ~3 pathways -localizing sound sources -using sounds to guide movements -projects to frontal and parietal ``` 2- Ventral pathways - linguistic function - identifying the source of speech (who is speaking or what is emitting sounds); learning voices - Uncinate fasciculus - Arcuate fasciculus

Answer 6

1- Broca's (44,45) 2- Wenicke's (22)

Answer 7

Brodmann's area 22 acts to decode the sounds of language so that spoken as well as written words and sentences can be understood and comprehended this is where sounds that you are hearing get interpreted as language. also determines what you are saying

Answer 8

Brodmann's area 44,45) final sequential (syntactical, grammical) inprint so as to become organized and expressed as temporally ordered motoric linguistic articulations (speech) receives the command to say something from Wernicke's. Allows you to say something, line up works in a way that makes sense. Then sends info to motor strip to physically say the words.

Answer 9

partial or complete loss of language abilities following brain damage, often without the loss of cognitive faculties or the ability to move the muscles used in speech

Answer 10

=inability to find words

Answer 11

=inability to read

Answer 12

=inability to write

Answer 13

repeating a spoken word: | auditory cortex-->

Answer 14

=bilateral destruction of A1 individual becomes cortically deaf although able to hear they cannot perceive or comprehend non-verbal sounds or understand spoken language Wernicke's area in the L hemisphere are disconnected from all sources of auditory input and thus cannot extract meaning from the auditory environment= AUDITORY AGNOSIA these patients are NOT deaf, no permanent loss of acoustic sensitivity - this is bc sounds continue to be received in thalamic and subcortical centers including the amygdala. Hence, the patients can still detect sounds. However, they are unable to identify them and cannot recognize the sounds of speech, including spoken language - never the less, these patient can still speak. unfortunately, they are unable to perceive the words that they are saying as that info can no longer to received within the neocortex and can't be transferred to Wernicke's area which is responsible for comprehending the sounds of speech

Answer 15

=non-fluent speech few words, short sentences, any many pauses the words that can be produced come with great effort and often distorted the melodic intonation is flat and mono pitched. this gives the speech the general appearance of a telegraphic nature, because of the deletion of function words and disturbances in word order. the repetition of words and phrases is impaired aural comprehension for conversational speech is relatively intact. there is often an accompanying R hemiparesis involved the face, arm and leg

Answer 16

patient does not appear to have any difficulty articulating speech, but may be paraphasic comprehension of speech is impaired and sometimes as much as single words are not comprehended speaks in meaningless jargon, "neoligistic jargon" devoid of any content but free use of verb tenses, clauses and subordinates

Answer 17

fluent paraphasic expression that is characterized by numerous phonetic substitutions ("fetter" for "better") comprehension is intact severe impairment of repetition reading aloud is characterized by paraphasic output but comprehension is good writing impairment is mild frequent self corrections patient would know what he wanted to say but can't say it could not repeat simple statements, read out loud or write sentences are usually short and often unrelated to each other arcuate fasciculus is knocked out but wernicke's is knocked out (similar to wenicke's aphasia- difference is they understand!!)

Answer 18

the cortical border zones surrounding the language axis have been destroyed the language axis of the L hemisphere becomes completely disconnected from surrounding cortical tissue but presumably remains an intact functional unit the cerebrum is unable to communicate with the language zones. as such, an individual in unable to verbally describe what they see, feel, touch, or desire. moreover, because the language axis can't communicate with the rest of the brain, linguistic comprehension is largely abolished communication b/w wernicke's, broca's and the inferior parietal lobule is maintained, associations from other brain regions can't reach the speech center -although able to talk, the pt has nothing to say. moreover, although able to see and hear, the patient is unable to linguistically understand what they perceive. however, they are capable of generating automatic-like responses to well known phrases, prayers or songs

Answer 19

splenium of CC disconnection of the language centers from visual perceptual areas patient can't read but other language functions are intact pt must have a lesion of the L occipital lobe that also includes the pathways connecting the visual perceptual areas. these pathways make up the splenium of CC this produces a visual field cut on the R side and visual info can only be perceived by the R hemisphere. since the connections b/w the R hemisphere visual perception areas the L hemisphere language centers are lesioned, the pt can't decode the language related visual info and can't read. Howevere, the pt comprehends auditory info and can write and speak normally. this results in the paradoxical symptoms of a pt who can write spontaneously but can't read their own writing

Answer 20

can't write presumably the parietal lobe contracts the written-word images (probably via interaction with Wernicke's area) which assists in converting these into graphemes these motor-graphemes (or written word/letter images) are then transmitted to the L frontal convexity (broca's and exner's area) for grapheme conversion and motoric expression

Answer 21

1-linguistic stage - involves the encoding of auditory and visual info into syntactical-lexical unites- the symbols for letters and written words - this is mediated through the angular gyrus which thus provides the linguistic rules which subserve writing 2-motor-expressive-praxic stage -this stage is mediated presumably by Exner's writing area (premotor area)

Answer 22

b/c different regions of the brain contribute to the ability to write, damage to these differ areas, therefore, affect different aspects of the ability to write. thus, there are different subtypes of agaphia, depending on which areas of the brain have been damaged ``` frontal agraphia pure agraphia alexic agraphia apraxic agraphia spatial agraphia ```