Reading and Dyslexia

Question 1

What is the word superiority effect?

Answer 1

• Visual processing time is not strongly affected by length, suggesting letters are not analysed one by one e.g., psychology vs. sky
• Letters identification is affected by whether it makes up a word or not e.g., carpet vs tae cat
• Letter identification has top-down influences from word knowledge - the brain stores some sort of “word forms”. When word form is lost, you develop “word blindness”

Question 2

What is word blindness?

Answer 2

Incapability to understand written words

Question 3

Give a case study of word blindness:

Answer 3

Monsieur C - incapable of understanding written words.
- Autopsy by neurologist Joseph Dejerine shows stroke damage to the left ventral occipito-temporal cortex (vOTC)

Question 4

Is the Visual Word Form Area (VWFA) located in the left brain only?

Answer 4

• It is only on the left. There is no right-brain equivalent of a VWFA
  (Split-brain Patient A.C. cannot recognise words presented in the left hemifield. Visual information in the right visual cortex cannot be sent across to the left vOTC for word form processing
• Words shown in both hemifields activate the VWFA more than consonant strings
• Only the left vOTC seems to be specialised for word form processing

Question 5

What is acquired dyslexia?

Answer 5

Reading difficulties developed due to acquired brain damage (injuries, stroke, dementia etc.)

Question 6

What are the two types of acquired dyslexia?

Answer 6

1. Peripheral Dyslexia
2. Central Dyslexia

(see Lecture 15, slide 23)

Question 7

How is peripheral dyslexia acquired?

Answer 7

Disruption of early visual-attentional processing (letter & words)
- Includes: Pure Alexia, Attentional Dyslexia, Neglect Dyslexia

Question 8

What is Central Dyslexia?

Answer 8

Disruption of phonological or semantic processing after visual word form processing
- Includes: Surface Dyslexia, Phonological Dyslexia, Deep Dyslexia

Question 9

What is Pure alexia?

Answer 9

Word blindness

Question 10

What is attentional dyslexia?

Answer 10

• Difficulty in separating constituent letters/words
• Letter migration errors

Question 11

What is neglect dyslexia?

Answer 11

• Letter substitution errors on one side (contralateral lesion)

Question 12

What is surface dyslexia?

Answer 12

• Can’t pronounce irregular words like pint
• Patients know the rules of regular pronunciation. When the pronunciation is irregular, they follow the regular pronunciation

Question 13

What is phonological dyslexia?

Answer 13

• Can’t pronounce non-words
• Fine with real words (regular and irregular)
• Tend to read a non-word as a real word e.g., churse –> nurse
• They tend to show problems in phonological processing

Question 14

What is deep dyslexia?

Answer 14

• Read real words with semantic errors
• Can read real words but reading is error-prone:
  ~ Semantic Errors: Cat –> Dog
  ~ Derivational Errors: Beg –> Beggar
  ~ Concrete words > abstract words –> wine and truth