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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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Relationship between the two putatively compensatory functional connections of the left fusiform gyrus (L.FFG) seed.The scatterplot represents the relationships between the two L.FFG connections (one with R.MOG and another with R.MPFC). 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: The correlation between these two L.FFG connections was significantly negative across all groups, across dyslexia groups, and in the full remediation group.
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pone-0055454-g006: Relationship between the two putatively compensatory functional connections of the left fusiform gyrus (L.FFG) seed.The scatterplot represents the relationships between the two L.FFG connections (one with R.MOG and another with R.MPFC). 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: The correlation between these two L.FFG connections was significantly negative across all groups, across dyslexia groups, and in the full remediation group.

Mentions: Given that L.FFG is involved in both functional connections (L.FFG-R.MOG, L.FFG-R.MPFC) associated with compensatory changes, an obvious question regards the relationship between these two sets of L.FFG connections. We examined their relationship (Figure 6). The correlation between L.FFG iFC with R.MOG and with R.MPFC was significantly negative across all groups (R2 = 0.39, n = 44, p<0.001) as well as across dyslexia groups (R2 = 0.38, n = 33, p<0.001). When examining groups individually, this relationship was significant in the full remediation group (Dys-RS, R2 = 0.61, n = 11, p<0.01). That is, children with stronger positive L.FFG-R.MOG connectivity were characterized by stronger negative iFC for the L.FFG-R.MPFC circuit, and this was particularly true in children in the full remediation group.


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)

Relationship between the two putatively compensatory functional connections of the left fusiform gyrus (L.FFG) seed.The scatterplot represents the relationships between the two L.FFG connections (one with R.MOG and another with R.MPFC). 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: The correlation between these two L.FFG connections was significantly negative across all groups, across dyslexia groups, and in the full remediation group.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3569450&req=5

pone-0055454-g006: Relationship between the two putatively compensatory functional connections of the left fusiform gyrus (L.FFG) seed.The scatterplot represents the relationships between the two L.FFG connections (one with R.MOG and another with R.MPFC). 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: The correlation between these two L.FFG connections was significantly negative across all groups, across dyslexia groups, and in the full remediation group.
Mentions: Given that L.FFG is involved in both functional connections (L.FFG-R.MOG, L.FFG-R.MPFC) associated with compensatory changes, an obvious question regards the relationship between these two sets of L.FFG connections. We examined their relationship (Figure 6). The correlation between L.FFG iFC with R.MOG and with R.MPFC was significantly negative across all groups (R2 = 0.39, n = 44, p<0.001) as well as across dyslexia groups (R2 = 0.38, n = 33, p<0.001). When examining groups individually, this relationship was significant in the full remediation group (Dys-RS, R2 = 0.61, n = 11, p<0.01). That is, children with stronger positive L.FFG-R.MOG connectivity were characterized by stronger negative iFC for the L.FFG-R.MPFC circuit, and this was particularly true in children in the full remediation group.

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