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Cortical signatures of dyslexia and remediation: an intrinsic functional connectivity approach.

Koyama MS, Di Martino A, Kelly C, Jutagir DR, Sunshine J, Schwartz SJ, Castellanos FX, Milham MP - PLoS ONE (2013)

Bottom Line: The full remediation group also exhibited stronger negative iFC between the same L.FFG seed and right medial prefrontal cortex (R.MPFC), a core region of the default network These results suggest that behavioral remediation may be associated with compensatory changes anchored in L.FFG, which reflect atypically stronger coupling between posterior visual regions (L.FFG-R.MOG) and greater functional segregation between task-positive and task-negative regions (L.FFG-R.MPFC).These findings were bolstered by significant relationships between the strength of the identified functional connections and literacy scores.We conclude that examining iFC can reveal cortical signatures of dyslexia with particular promise for monitoring neural changes associated with behavioral remediation.

View Article: PubMed Central - PubMed

Affiliation: Rutgers University Center for Molecular and Behavioral Neuroscience, Newark, New Jersey, USA.

ABSTRACT
This observational, cross-sectional study investigates cortical signatures of developmental dyslexia, particularly from the perspective of behavioral remediation. We employed resting-state fMRI, and compared intrinsic functional connectivity (iFC) patterns of known reading regions (seeds) among three dyslexia groups characterized by (a) no remediation (current reading and spelling deficits), (b) partial remediation (only reading deficit remediated), and (c) full remediation (both reading and spelling deficits remediated), and a group of age- and IQ-matched typically developing children (TDC) (total N = 44, age range = 7-15 years). We observed significant group differences in iFC of two seeds located in the left posterior reading network - left intraparietal sulcus (L.IPS) and left fusiform gyrus (L.FFG). Specifically, iFC between L.IPS and left middle frontal gyrus was significantly weaker in all dyslexia groups, irrespective of remediation status/literacy competence, suggesting that persistent dysfunction in the fronto-parietal attention network characterizes dyslexia. Additionally, relative to both TDC and the no remediation group, the remediation groups exhibited stronger iFC between L.FFG and right middle occipital gyrus (R.MOG). The full remediation group also exhibited stronger negative iFC between the same L.FFG seed and right medial prefrontal cortex (R.MPFC), a core region of the default network These results suggest that behavioral remediation may be associated with compensatory changes anchored in L.FFG, which reflect atypically stronger coupling between posterior visual regions (L.FFG-R.MOG) and greater functional segregation between task-positive and task-negative regions (L.FFG-R.MPFC). These findings were bolstered by significant relationships between the strength of the identified functional connections and literacy scores. We conclude that examining iFC can reveal cortical signatures of dyslexia with particular promise for monitoring neural changes associated with behavioral remediation.

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Compensatory changes in iFC of the left fusiform gyrus (L.FFG) in the remediation groups.The box-and-whisker plots depict (A) L.FFG-R.MOG iFC and (B) L.FFG-R.MPFC iFC for each group and group differences, whereas the scatterplots represent the relationships between the strength of these connections and reading as well as spelling scores. iFC = intrinsic Functional Connectivity, R.MOG = Right Middle Occipital Gyrus, R.MPFC = Right Medial Prefrontal Cortex, Dys-N = Dyslexia with No Remediation, Dys-R = Dyslexia with Reading Remediation, Dys-RS = Dyslexia with Reading and Spelling Remediation, TDC = Typically Developing Children, Dys = Dyslexia, ss = standard scores: ***p<0.001, **p<0.01 (corrected): Both the partial and full remediation groups exhibited stronger L.FFG-R.MOG iFC, relative to both DTC and Dys-N, whereas the full remediation group exhibited stronger negative L.FFG-R.MPFC iFC, relative to TDC, Dys-N, and Dys-R.
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pone-0055454-g005: Compensatory changes in iFC of the left fusiform gyrus (L.FFG) in the remediation groups.The box-and-whisker plots depict (A) L.FFG-R.MOG iFC and (B) L.FFG-R.MPFC iFC for each group and group differences, whereas the scatterplots represent the relationships between the strength of these connections and reading as well as spelling scores. iFC = intrinsic Functional Connectivity, R.MOG = Right Middle Occipital Gyrus, R.MPFC = Right Medial Prefrontal Cortex, Dys-N = Dyslexia with No Remediation, Dys-R = Dyslexia with Reading Remediation, Dys-RS = Dyslexia with Reading and Spelling Remediation, TDC = Typically Developing Children, Dys = Dyslexia, ss = standard scores: ***p<0.001, **p<0.01 (corrected): Both the partial and full remediation groups exhibited stronger L.FFG-R.MOG iFC, relative to both DTC and Dys-N, whereas the full remediation group exhibited stronger negative L.FFG-R.MPFC iFC, relative to TDC, Dys-N, and Dys-R.

Mentions: One-way ANOVA, with group as level (4 levels: no remediation, partial remediation, full remediation, and TDC), identified a significant main effect of group (Z >2.3; p<0.05, corrected) on iFC associated with two seeds in the posterior reading network – the left intraparietal sulcus (L.IPS) and left fusiform gyrus (L.FFG). Specifically, we observed a main effect of group on iFC between the L.IPS seed and left middle frontal gyrus (L.MFG, BA9; x = −34, y = 4, z = 40; see Figure 4), and on iFC between the L.FFG seed and the right middle occipital gyrus, extending towards the right intraparietal sulcus (R.MOG, BA19; x = 34, y = −70, z = 4; see Figure 5.A), as well as between the L.FFG seed and the right medial prefrontal cortex (R.MPFC, BA33; x = 14, y = 46, z = 10; see Figure 5.B), a region corresponding to the anterior region of the dorsal MPFC [82].


Cortical signatures of dyslexia and remediation: an intrinsic functional connectivity approach.

Koyama MS, Di Martino A, Kelly C, Jutagir DR, Sunshine J, Schwartz SJ, Castellanos FX, Milham MP - PLoS ONE (2013)

Compensatory changes in iFC of the left fusiform gyrus (L.FFG) in the remediation groups.The box-and-whisker plots depict (A) L.FFG-R.MOG iFC and (B) L.FFG-R.MPFC iFC for each group and group differences, whereas the scatterplots represent the relationships between the strength of these connections and reading as well as spelling scores. iFC = intrinsic Functional Connectivity, R.MOG = Right Middle Occipital Gyrus, R.MPFC = Right Medial Prefrontal Cortex, Dys-N = Dyslexia with No Remediation, Dys-R = Dyslexia with Reading Remediation, Dys-RS = Dyslexia with Reading and Spelling Remediation, TDC = Typically Developing Children, Dys = Dyslexia, ss = standard scores: ***p<0.001, **p<0.01 (corrected): Both the partial and full remediation groups exhibited stronger L.FFG-R.MOG iFC, relative to both DTC and Dys-N, whereas the full remediation group exhibited stronger negative L.FFG-R.MPFC iFC, relative to TDC, Dys-N, and Dys-R.
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Related In: Results  -  Collection

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pone-0055454-g005: Compensatory changes in iFC of the left fusiform gyrus (L.FFG) in the remediation groups.The box-and-whisker plots depict (A) L.FFG-R.MOG iFC and (B) L.FFG-R.MPFC iFC for each group and group differences, whereas the scatterplots represent the relationships between the strength of these connections and reading as well as spelling scores. iFC = intrinsic Functional Connectivity, R.MOG = Right Middle Occipital Gyrus, R.MPFC = Right Medial Prefrontal Cortex, Dys-N = Dyslexia with No Remediation, Dys-R = Dyslexia with Reading Remediation, Dys-RS = Dyslexia with Reading and Spelling Remediation, TDC = Typically Developing Children, Dys = Dyslexia, ss = standard scores: ***p<0.001, **p<0.01 (corrected): Both the partial and full remediation groups exhibited stronger L.FFG-R.MOG iFC, relative to both DTC and Dys-N, whereas the full remediation group exhibited stronger negative L.FFG-R.MPFC iFC, relative to TDC, Dys-N, and Dys-R.
Mentions: One-way ANOVA, with group as level (4 levels: no remediation, partial remediation, full remediation, and TDC), identified a significant main effect of group (Z >2.3; p<0.05, corrected) on iFC associated with two seeds in the posterior reading network – the left intraparietal sulcus (L.IPS) and left fusiform gyrus (L.FFG). Specifically, we observed a main effect of group on iFC between the L.IPS seed and left middle frontal gyrus (L.MFG, BA9; x = −34, y = 4, z = 40; see Figure 4), and on iFC between the L.FFG seed and the right middle occipital gyrus, extending towards the right intraparietal sulcus (R.MOG, BA19; x = 34, y = −70, z = 4; see Figure 5.A), as well as between the L.FFG seed and the right medial prefrontal cortex (R.MPFC, BA33; x = 14, y = 46, z = 10; see Figure 5.B), a region corresponding to the anterior region of the dorsal MPFC [82].

Bottom Line: The full remediation group also exhibited stronger negative iFC between the same L.FFG seed and right medial prefrontal cortex (R.MPFC), a core region of the default network These results suggest that behavioral remediation may be associated with compensatory changes anchored in L.FFG, which reflect atypically stronger coupling between posterior visual regions (L.FFG-R.MOG) and greater functional segregation between task-positive and task-negative regions (L.FFG-R.MPFC).These findings were bolstered by significant relationships between the strength of the identified functional connections and literacy scores.We conclude that examining iFC can reveal cortical signatures of dyslexia with particular promise for monitoring neural changes associated with behavioral remediation.

View Article: PubMed Central - PubMed

Affiliation: Rutgers University Center for Molecular and Behavioral Neuroscience, Newark, New Jersey, USA.

ABSTRACT
This observational, cross-sectional study investigates cortical signatures of developmental dyslexia, particularly from the perspective of behavioral remediation. We employed resting-state fMRI, and compared intrinsic functional connectivity (iFC) patterns of known reading regions (seeds) among three dyslexia groups characterized by (a) no remediation (current reading and spelling deficits), (b) partial remediation (only reading deficit remediated), and (c) full remediation (both reading and spelling deficits remediated), and a group of age- and IQ-matched typically developing children (TDC) (total N = 44, age range = 7-15 years). We observed significant group differences in iFC of two seeds located in the left posterior reading network - left intraparietal sulcus (L.IPS) and left fusiform gyrus (L.FFG). Specifically, iFC between L.IPS and left middle frontal gyrus was significantly weaker in all dyslexia groups, irrespective of remediation status/literacy competence, suggesting that persistent dysfunction in the fronto-parietal attention network characterizes dyslexia. Additionally, relative to both TDC and the no remediation group, the remediation groups exhibited stronger iFC between L.FFG and right middle occipital gyrus (R.MOG). The full remediation group also exhibited stronger negative iFC between the same L.FFG seed and right medial prefrontal cortex (R.MPFC), a core region of the default network These results suggest that behavioral remediation may be associated with compensatory changes anchored in L.FFG, which reflect atypically stronger coupling between posterior visual regions (L.FFG-R.MOG) and greater functional segregation between task-positive and task-negative regions (L.FFG-R.MPFC). These findings were bolstered by significant relationships between the strength of the identified functional connections and literacy scores. We conclude that examining iFC can reveal cortical signatures of dyslexia with particular promise for monitoring neural changes associated with behavioral remediation.

Show MeSH
Related in: MedlinePlus