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Reading networks in children with dyslexia compared to children with ocular motility disturbances revealed by fMRI.

Saralegui I, Ontañón JM, Fernandez-Ruanova B, Garcia-Zapirain B, Basterra A, Sanz-Arigita EJ - Front Hum Neurosci (2014)

Bottom Line: Developmental dyslexia is a neurological disorder the underlying biological and cognitive causes of which are still being investigated, a key point, because the findings will determine the best therapeutic approach to use.We found that Spanish-speaking children with dyslexia have a brain circuit for reading that differs from that in children with monocular vision.That is, they seem to compensate for impairment in the phonological route through orthographic routes of both hemispheres.

View Article: PubMed Central - PubMed

Affiliation: Department of Neuroradiology, Osatek, Galdakao-Usansolo Hospital Galdakao, Spain.

ABSTRACT
Key PointsDyslexia is a neurological disorder with a genetic origin, but the underlying biological and cognitive causes are still being investigated.This study compares the brain activation pattern while reading in Spanish, a semitransparent language, in three groups of children: typically developing readers, dyslexic readers and readers with functional monocular vision.Based on our results Dyslexia would be a neurological disorder not related to vision impairments and would require a multidisciplinary treatment based on improving phonological awareness and language development. Developmental dyslexia is a neurological disorder the underlying biological and cognitive causes of which are still being investigated, a key point, because the findings will determine the best therapeutic approach to use. Using functional magnetic resonance imaging, we studied the brain activation pattern while reading in the language-related cortical areas from the two reading routes, phonological and orthographic, and the strength of their association with reading scores in 66 Spanish-speaking children aged 9-12 years divided into three groups: typically developing readers (controls), dyslexic readers and readers with monocular vision due to ocular motility disorders but with normal reading development, to assess whether (or not) the neuronal network for reading in children with dyslexia has similarities with that in children with impaired binocular vision due to ocular motility disorders. We found that Spanish-speaking children with dyslexia have a brain circuit for reading that differs from that in children with monocular vision. Individuals with dyslexia tend to hypoactivate some of the language-related areas in the left hemisphere engaged by the phonological route, especially the visual word form area and left Wernicke's area, and try to compensate this deficit by activating language-related areas related to the orthographic route, such as the anterior part of the visual word form area and the posterior part of both middle temporal gyri. That is, they seem to compensate for impairment in the phonological route through orthographic routes of both hemispheres. Our results suggest that ocular motility disturbances do not play a causal role in dyslexia. Dyslexia seems to be a neurological disorder that is unrelated to vision impairments and requires early recognition and multidisciplinary treatment, based on improving phonological awareness and language development, to achieve the best possible outcome.

No MeSH data available.


Related in: MedlinePlus

Surface rendering of the location of the ROI evaluated in fMRI analysis (A) and group differences in mean activation for the three groups in the selected areas (B) for the pseudoword reading condition of the lexical decision task. Parts of left and right Broca's area (left BA 45: −34, 20, −1; right BA 45: 37, 19, −4); left MTG (BA 21: −52, −39, −1) and right MTG (BA 21: 52, −32, −2); left VWFA 1 (−45, −41, −21), and left Wernicke's area (BA 22: −55, −41, 24), *P < 0.05, **P < 0.01.
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Figure 3: Surface rendering of the location of the ROI evaluated in fMRI analysis (A) and group differences in mean activation for the three groups in the selected areas (B) for the pseudoword reading condition of the lexical decision task. Parts of left and right Broca's area (left BA 45: −34, 20, −1; right BA 45: 37, 19, −4); left MTG (BA 21: −52, −39, −1) and right MTG (BA 21: 52, −32, −2); left VWFA 1 (−45, −41, −21), and left Wernicke's area (BA 22: −55, −41, 24), *P < 0.05, **P < 0.01.

Mentions: Six areas were studied in the ROI analysis of this condition (Figure 3).


Reading networks in children with dyslexia compared to children with ocular motility disturbances revealed by fMRI.

Saralegui I, Ontañón JM, Fernandez-Ruanova B, Garcia-Zapirain B, Basterra A, Sanz-Arigita EJ - Front Hum Neurosci (2014)

Surface rendering of the location of the ROI evaluated in fMRI analysis (A) and group differences in mean activation for the three groups in the selected areas (B) for the pseudoword reading condition of the lexical decision task. Parts of left and right Broca's area (left BA 45: −34, 20, −1; right BA 45: 37, 19, −4); left MTG (BA 21: −52, −39, −1) and right MTG (BA 21: 52, −32, −2); left VWFA 1 (−45, −41, −21), and left Wernicke's area (BA 22: −55, −41, 24), *P < 0.05, **P < 0.01.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4237045&req=5

Figure 3: Surface rendering of the location of the ROI evaluated in fMRI analysis (A) and group differences in mean activation for the three groups in the selected areas (B) for the pseudoword reading condition of the lexical decision task. Parts of left and right Broca's area (left BA 45: −34, 20, −1; right BA 45: 37, 19, −4); left MTG (BA 21: −52, −39, −1) and right MTG (BA 21: 52, −32, −2); left VWFA 1 (−45, −41, −21), and left Wernicke's area (BA 22: −55, −41, 24), *P < 0.05, **P < 0.01.
Mentions: Six areas were studied in the ROI analysis of this condition (Figure 3).

Bottom Line: Developmental dyslexia is a neurological disorder the underlying biological and cognitive causes of which are still being investigated, a key point, because the findings will determine the best therapeutic approach to use.We found that Spanish-speaking children with dyslexia have a brain circuit for reading that differs from that in children with monocular vision.That is, they seem to compensate for impairment in the phonological route through orthographic routes of both hemispheres.

View Article: PubMed Central - PubMed

Affiliation: Department of Neuroradiology, Osatek, Galdakao-Usansolo Hospital Galdakao, Spain.

ABSTRACT
Key PointsDyslexia is a neurological disorder with a genetic origin, but the underlying biological and cognitive causes are still being investigated.This study compares the brain activation pattern while reading in Spanish, a semitransparent language, in three groups of children: typically developing readers, dyslexic readers and readers with functional monocular vision.Based on our results Dyslexia would be a neurological disorder not related to vision impairments and would require a multidisciplinary treatment based on improving phonological awareness and language development. Developmental dyslexia is a neurological disorder the underlying biological and cognitive causes of which are still being investigated, a key point, because the findings will determine the best therapeutic approach to use. Using functional magnetic resonance imaging, we studied the brain activation pattern while reading in the language-related cortical areas from the two reading routes, phonological and orthographic, and the strength of their association with reading scores in 66 Spanish-speaking children aged 9-12 years divided into three groups: typically developing readers (controls), dyslexic readers and readers with monocular vision due to ocular motility disorders but with normal reading development, to assess whether (or not) the neuronal network for reading in children with dyslexia has similarities with that in children with impaired binocular vision due to ocular motility disorders. We found that Spanish-speaking children with dyslexia have a brain circuit for reading that differs from that in children with monocular vision. Individuals with dyslexia tend to hypoactivate some of the language-related areas in the left hemisphere engaged by the phonological route, especially the visual word form area and left Wernicke's area, and try to compensate this deficit by activating language-related areas related to the orthographic route, such as the anterior part of the visual word form area and the posterior part of both middle temporal gyri. That is, they seem to compensate for impairment in the phonological route through orthographic routes of both hemispheres. Our results suggest that ocular motility disturbances do not play a causal role in dyslexia. Dyslexia seems to be a neurological disorder that is unrelated to vision impairments and requires early recognition and multidisciplinary treatment, based on improving phonological awareness and language development, to achieve the best possible outcome.

No MeSH data available.


Related in: MedlinePlus