Task 5

Question 1

What is dyslexia?

Answer 1

It is a specific learning disability that is neurobiological in nature.

It is characterized by difficulties with accurate and/or fluent word recognition and by poor spelling and decoding abilities.

These difficulties typically result from a deficit in the phonological component of language that is often unexpected in relation to other cognitive abilities and the provision of effective classroom instruction

Question 2

What are the characteristics of dyslexia?

Answer 2

It is characterized by difficulties with accurate and/or fluent word recognition and by poor spelling and decoding abilities.

These difficulties typically result from a deficit in the phonological component of language that is often unexpected in relation to other cognitive abilities and the provision of effective classroom instruction

Question 3

Name the four stages that help children learn to read.

Answer 3

Rapid auditory processing
Phonological awareness
Orthography
Visual Word Processing

Question 4

What is rapid auditory processing?

Answer 4

Processing of rapidly changing information

Facilitates auditory discrimination necessary to distinguish phonemes (the smallestmeaningful unit of sound in a particular language).

Question 5

What are phonemes?

Answer 5

the smallest meaningful unit of sound in a particular language

Question 6

What is phonological awareness?

Answer 6

use of sound structure of language: identification & manipulation of sound structure of words

Question 7

Why is phonological awareness important and when does it develop?

Answer 7

It is important for learning how to read

Develops around 6 years old when children are taught to read.

Question 8

What is orthography?

Answer 8

recognize that letters & letter strings represent the sounds of spoken language

Be able to pull apart spoken words into elemental particles of speech (phonemes).

Insight that letters in a written word represent these sounds.

Question 9

What goes wrong in the reading development of children with dyslexia?

Answer 9

Deficits in rapid auditory processing –> inability to discriminate auditory cues necessary to distinguish phonemes

Deficits in phonological awareness –> inability to manipulate the sound structure of words –? inability to read

Deficits in specialized visual word processing

Deficits in orthography

Question 10

Explain how deficits in decoding and comprehension can affect dyslexic’s ability to read.

Answer 10

in dyslexia, a deficit at the level of the phonologic module impairs the ability to segment the spoken word into its underlying phonologic elements and then link each letter(s) to its corresponding sound.

As a result, the reader experiences difficulty, first in decoding the word and then in identifying it. The phonologic deficit is domain-specific; that is, it is independent of other, nonphonologic, abilities
.
The problem is that the affected reader cannot use his or her higher-order linguistic skills to access the meaning until the printed word has first been decoded and identified

Question 11

It is found that the phonological deficit observed in dyslexic children is domain specific. What does that mean and what does it say about higher order linguistic skills?

Answer 11

it is independent of other, nonphonologic, abilities

The problem is that the affected reader cannot use his or her higher-order linguistic skills to access the meaning until the printed word has first been decoded and identified

Question 12

Which areas are involved in compensation as observed in some dyslexic individuals (e.g. older)?

Answer 12

Areas in the inferior frontal gyrus in both hemispheres

Right hemisphere of the left occipito-temporal word form area

Question 13

How do dyslexics compensate?

Answer 13

They may use executive functions to learn to read/memorize words

Question 14

What was the aim of Maurer et al’s study?

Answer 14

investigated how tuning (focused/specialization…) of visual activity for print advances in the same children before and after initial reading training in school

Question 15

Describe the method used in Maurer’s study

Answer 15

Method:
Children with history of dyslexia vs. those without

2 assessment time: kindergarten vs. 2nd grade – visual & auditory acuity assessed, parents filled out questionnaires regarding deviant behaviour & neurological disorders.

T1: intelligence, phonological abilitys & word/letter knowledge tested.

T2: tests for reading and spelling. Questionniare on handedness.

Question 16

Describe the procedure in Maurer’s study

Answer 16

Stimuli: word pseudoword, symbol & picture conditions shown on white background

72 stimuli per condition in 2 blocks

Test: participants asked to press mouse button with preferred hand after an immediate stimulus repetition.

ERP recordings

Question 17

What is the function of N1?

Answer 17

It specializes on written words

Question 18

What is the function of P1?

Answer 18

It is more related to symbols than words

Question 19

What were Maurer’s findings in relation to visual specialization for print (word-symbol contrasts)?

Answer 19

More accurate at detecting targets for both children after training, especially for words & especially for control groups

In general, children had faster responding in 2nd grade and faster reaction time for symbols than words.

Question 20

What was Maurer’s results in relation to the ERP P1?

Answer 20

Early P1 = smaller for words than symbols after reading training
Dyslexa = smaller P1 amplitutes than controls for both stimulus & both age levels

Question 21

What was Maurer’s findings regarding N1?

Answer 21

Stronger for words than symbols but mainly in 2nd grade, but less in children with dyslexia.

control: word-symbol difference was slight right-laterized in kindergarten, then left laterized in 2nd grade. – no difference found in dyslexic children

Question 22

What does the data regarding P1 and N1 imply about dyslexic children?

Answer 22

Reduced P1 in Kindergarten implies that the dyslexic children already have deficits in identifying symbols before they even start interacting with letters.

Dyslexic children have deficits in identifying written words even after training.

Question 23

Which brain region was correlated with reading ability in Maurer’s study?

Answer 23

Correlation between group and reading ability + negative word-symbol N1 effects at occipito-temporal in 2nd grade.

Question 24

Which brain area was specialized in reading for controls following training in the Maurer study?

Answer 24

Control at 2nd grade = inferior & lateral occipito temporal cortex for N1

Question 25

What were Maurer's findings regarding the neural underpinnings for visual processing in controls?

Answer 25

N1 tuning observed in kindergarten (more prominent than adults) Increase in N1 specialization with reading training (2nd grade) Specialization for print in 2nd grade = left inferior occipitotemporal region, some on the right hemishphere

Question 26

What were Maurer's findings regarding the neural underpinnings for visual processing in dyslexic children?

Answer 26

Slightly larger specialization of right hemisphere in kindergarten No significant N1 specialization for 2nd graders with dyslexia after reading training

Question 27

What is the neural underpinning for visual processing in normal adults?

Answer 27

N1/N170 = word-specific processing Words = larger N1 amplitudes than low-level visual control stimuli (e.g. symbol strings) Left hemisphere

Question 28

What is the neural underpinnings for visual processing in dyslexic adults?

Answer 28

Reduced activation in inferior occipito-temporal regions = visual word processing Fast N1/N170 is attenuated

Question 29

What was the aim of Temple's study?

Answer 29

determine if dyslexic children have a disruption in temporo-parietal response to phonological processing of visual letters.

Question 30

Describe the method used in Temple's study

Answer 30

Method: 8=12 years old. normal reading vs. dyslexic. Blocks: 5 stimulus pairs, 6 blocks Rhyming: press a button if the names of two visually presented letters rhymed with each other, e.g. D and T. – asseses phonological analysis of letter names Match letters: e child pressed a button if two visually presented letters were the same, e.g. D and D Match lines: pushed a button if two lines were the same

Question 31

What three tasks were used in Temple's study?

Answer 31

Rhyming: press a button if the names of two visually presented letters rhymed with each other, e.g. D and T. – asseses phonological analysis of letter names Match letters: e child pressed a button if two visually presented letters were the same, e.g. D and D Match lines: pushed a button if two lines were the same

Question 32

What were the results regarding phonological processing in dyslexic children in Temple's study?

Answer 32

Phonological processing: Dyslexic children (8±12 years old) were selectively impaired for making phonological (rhyme) judgments, compared with children without reading disability. Further, rhyme judgment performance correlated with reading scores in the dyslexic children; this suggests that the rhyme judgment task invoked phonological processes important for reading. The dyslexic children also exhibited reduced left-hemisphere temporo-parietal brain activity during the rhyme task, which required phonological analysis dyslexic children failed to activate this area at all above baseline this de®cit appears to be speci®cally phonological, because visual processing of letters in the match letters task did not activate this area in either dyslexic or normal-reading children left frontal activation was evident in both dyslexic and control children making phonological judgments

Question 33

What were Temple's results regarding orthographic processing?

Answer 33

An unanticipated and larger difference between dyslexic and normal-reading children involved orthographic processing of single letter pairs (match letters vs match lines) despite equal accuracy in the match letters task for both groups Normal-reading children showed greater activity in a large extrastriate region when matching letters versus matching lines, which included bilateral (left greater than right) middle/superior occipital gyrus and superior parietal lobe. The dyslexic children did not show activity in the occipitalparietal area, and there was a signi®cant group difference in this region when the two groups were compared directly

Question 34

What were the conclusions of Temple's study?

Answer 34

Dyslexic children had impaired performance on a phonological task that correlated with their reading scores and those children failed to exhibit the left temporo-parietal activation seen in normal-reading children during phonological processing. The dyslexic children also showed reduced extra-striate activity during an orthographic task. These ®ndings indicate that dyslexia in childhood, when children are trying to learn how to read, may be characterized by impaired neural responses in a temporo-parietal region that is important for phonological processing and in extra-striate occipital regions that are important for orthographic processing

Question 35

What are the neural underpinnings of phonological processing?

Answer 35

Letter rhyming: both had activity in left frontal brain regions, but only TC children had activity in left temporo-parietal cortex. Letter matching: TC showed activity throughout the extrastriate cortex, especially in occipito-parietal regions. Dyslexics = had little activity in extrastriate cortex. Phonological processing = disruptions in left posterior language regions in both dyslexic adults and children Rapid auditory processing = left prefrontal regions disruptions in both adults and children White matter connecting posterior and frontal regions is disrupted in dyslexic adults . Left white matter organization is correlated with reading ability.