Disorders of Reading

Question 1

What is alexia with agraphia?

Answer 1

Impaired reading along with impaired spelling or writing

Question 2

What is alexia without agraphia?

Answer 2

• Impaired reading but intact spelling or writing
• Paradoxial inability to read words that they had just written

Question 3

Dejerine first coined the agraphia terms, what did he argue?

Answer 3

1) In the angular gyrus, there is a center for the visual images of letters that is necessary for both reading and writing
2) Damage to the center itself = would lead to alexia with agraphia
3) Dissconnection of the center from visual areas = alexia without agraphia

Question 4

How did Marshall & Newcombe come to propose a two-route model of reading?

Answer 4

The model was based on the error patterns..
- Surface dyslexia
- Deep dyslexia

Question 5

What is deep dyslexia associated with?

Answer 5

An impairment in the sound analysis system

Question 6

What is surface dyslexia associated with?

Answer 6

An impairment in the meaning analysis system

Question 7

What are the 3 potential routes for reading?

Answer 7

1) Visual Analysis System -> Visual Input Lexicon -> Semantic system -> Speech Output lexicon -> Phoneme level -> Speech

2) Visual analysis system -> Visual Input Lexicon -> Speech Output Lexicon -> Phoneme Level -> Speech

3) Visual analysis system -> Grapheme Phoneme Conversion -> Phoneme Level -> Speech

Question 8

Describe Peripheral Dyslexias

Answer 8

Occur early on in the visual analysis process for reading

Question 9

Describe Central Dyslexias

Answer 9

Disorders that happen once thye get past the analysis system

Question 10

What are the 3 types of dyslexias?

Answer 10

1) Neglect Dyslexia
2) Attentional Dyslexia
3) Letter By Letter Reading

Question 11

Define Neglect Dyslexia

Answer 11

Neglect half of the world

Ex. cowboy = boy
Ex. milk = chalk

Question 12

Define attentional dyslexia

Answer 12

Can see the whole world but can’t identify individual letters

Question 13

Define Letter-by-letter reading

Answer 13

Pure alexia completely abolished, you read letters better than words

• Very labored sequential process
• Shown the word book: “B-O-O-K… Book”
• Long words should take more time to read than short ones
• Script more difficult than print
• Can not read with breif presentations
• Impairment occurs after letter-form processing

Question 14

What route is impaired in letter-by-letter peripheral dyslexia?

Answer 14

There is an imapirment in their visual analysis system which leads to the subsequent pathway not being utilized
- Patients develop a compensatory procedure to circumvent the visual analysis system impairment

Question 15

Describe surface level dyslexia

Answer 15

Damage to sound analysis

1) Assigning inapproporatye sounds to ambiguous grapheme OR assigning phonetic value to silent grapheme
Ex. insect&raquo_space; insist
Ex. listen&raquo_space; liston

2) Regularization: Applying valid correspondence rules
Ex. disease&raquo_space; decease
Ex. gone&raquo_space; goan

3) Influenced by Regular vs. Irregular Word Manipulation

Question 16

What route is impaired in surface dyslexia?
- What do surface dyslexia errors reflect?

Answer 16

Impairment in the
Visual Analysis System -> Visual Input Lexicon -> Speech

Errors reflect attempts to read soley through graphene-phoneme correspondence rules

Question 17

What route is impaired in deep dyslexia?

Answer 17

the visual analysis system to visual input lexicon

Question 18

Describe the behaviour of deep dyslexia patients
Specific errors?

Answer 18

They do not extract phonetic information from words, instead they read as if words are an ideogram

Semantic Error
- ill&raquo_space; sick
- cheer&raquo_space; laugh

Visual
- life&raquo_space; wife
- sword&raquo_space; words

visual then semantic
- sympathy&raquo_space; orchestra
- favor&raquo_space; taste

there is a lack of a phonological check

Question 19

What is the right hemisphere hypothesis of deep dyslexia?

Answer 19

Patients aren’t reading though the left hemisphere AT ALL

• It’s not the selective damage of a single pathway, but BOTH pathways in one hemisphere
• Deep dyslexics have a damage LH system and are reading though the right hemisphere
• Word recognition is mediated by the visual input lexicon in the right hemisphere
• The RH doesn’t have the infrastructure to read phonologically leading to an over-reliance on semantic representations

Question 20

What can the RH do?

Answer 20

• Analyze orthographic (visual/written text) input
• Orthographic analysis leads to the semanticization NOT phonological interpretation
• Cannot produce speech

Question 21

What can the LH do?

Answer 21

• All functions
• Note that the speech production system is seperate and beleived to be in tact in deep dyslexia

Question 22

Whats happending in deep dyslexia in terms of hemispheres?

Answer 22

• Patients can produce speech but cannot gain access from print to the orthographic lexicon in the LH
• Thius the orthographic input enters the RH, semantic info sent over to the LH, and then there is phonological output

Question 23

What is evidence for lateralization in split brain patients?

Answer 23

When word stimuli shown to RH, cannot interpret rhyme or non-words

Question 24

What is evidence for laterization in left hemispherectomy patients?

Answer 24

Make semantic errors akin to DD

Question 25

Describe phonological dyslexia

Answer 25

In phonological dyslexia, patients have impaired non-word reading but intact lexical reading

They will “regularize” non-words: e.g. they will say the word “soot” when presented with “soof”

They respond with a real word because they can only read throguh their lexicon and can’t sound out the words phonologically

Question 26

But wait! the marcel model might be flawed. what indicates that thier model is flawed?

Answer 26

Are there really two routes that bypass the semantic system?

Is there really a ‘pure’ GPC route seperate from the lexicon? why?

Question 27

What do the errors made by surface level dyselxia patients indicate?

Answer 27

Errors have a hint of lexical involvement

• Ex. Show a patient “incense” and they say “increase” - increase is the more common word AND phonological pronounciation of incense
• Performance is also graded in a way that suggests word meaning/frequency knowledge
• In children: they try and mathc a new word to an old word that they know previously
• Sounding words out is a last resort