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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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The strength of the identified iFC in two typically developing child groups and a typical adult group.iFC = Intrinsic Functional Connectivity, L.IPS = Left Intraparietal Sulcus, L.MFG = Left Middle Frontal Gyrus, L. FFG = Left Fusiform Gyrus, R.MOG = Right Middle Occipital Gyrus, R.MPFC = Right Medial Prefrontal Cortex, N.S. = Not Significant, TDC-C = Typically Developing Children in the Current work (n = 11), TDC-P = Typically Developing children in the Previous work (n = 25) [39], TA = Typical Adults (n = 25): Group differences were observed neither between the two TDC groups nor between TDC and TA groups.
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pone-0055454-g007: The strength of the identified iFC in two typically developing child groups and a typical adult group.iFC = Intrinsic Functional Connectivity, L.IPS = Left Intraparietal Sulcus, L.MFG = Left Middle Frontal Gyrus, L. FFG = Left Fusiform Gyrus, R.MOG = Right Middle Occipital Gyrus, R.MPFC = Right Medial Prefrontal Cortex, N.S. = Not Significant, TDC-C = Typically Developing Children in the Current work (n = 11), TDC-P = Typically Developing children in the Previous work (n = 25) [39], TA = Typical Adults (n = 25): Group differences were observed neither between the two TDC groups nor between TDC and TA groups.

Mentions: A secondary analysis aimed to verify that the iFC patterns observed in the current TDC group are representative of normative/typical iFC profiles. As expected, pair-wise comparisons using unpaired t-tests revealed that, for all identified connections (L.IPS-L.MFG, L.FFG-R.MOG, and L.FFG-R.MPFC), there were no significant differences between the two TDC groups (Figure 7). This allows us to assert that the group differences observed in the present study reflect atypical/altered iFC patterns associated with dyslexia. In addition, for all identified connections, there were no significant differences between the TDC groups and the TA group (Figure 7), indicating that either they are not developmentally sensitive, or they are mature prior to age 7 (but see [39] for developmental differences for brain-behavior relationships with respect to L.FFG-R.MPFC iFC).


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)

The strength of the identified iFC in two typically developing child groups and a typical adult group.iFC = Intrinsic Functional Connectivity, L.IPS = Left Intraparietal Sulcus, L.MFG = Left Middle Frontal Gyrus, L. FFG = Left Fusiform Gyrus, R.MOG = Right Middle Occipital Gyrus, R.MPFC = Right Medial Prefrontal Cortex, N.S. = Not Significant, TDC-C = Typically Developing Children in the Current work (n = 11), TDC-P = Typically Developing children in the Previous work (n = 25) [39], TA = Typical Adults (n = 25): Group differences were observed neither between the two TDC groups nor between TDC and TA groups.
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Related In: Results  -  Collection

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

pone-0055454-g007: The strength of the identified iFC in two typically developing child groups and a typical adult group.iFC = Intrinsic Functional Connectivity, L.IPS = Left Intraparietal Sulcus, L.MFG = Left Middle Frontal Gyrus, L. FFG = Left Fusiform Gyrus, R.MOG = Right Middle Occipital Gyrus, R.MPFC = Right Medial Prefrontal Cortex, N.S. = Not Significant, TDC-C = Typically Developing Children in the Current work (n = 11), TDC-P = Typically Developing children in the Previous work (n = 25) [39], TA = Typical Adults (n = 25): Group differences were observed neither between the two TDC groups nor between TDC and TA groups.
Mentions: A secondary analysis aimed to verify that the iFC patterns observed in the current TDC group are representative of normative/typical iFC profiles. As expected, pair-wise comparisons using unpaired t-tests revealed that, for all identified connections (L.IPS-L.MFG, L.FFG-R.MOG, and L.FFG-R.MPFC), there were no significant differences between the two TDC groups (Figure 7). This allows us to assert that the group differences observed in the present study reflect atypical/altered iFC patterns associated with dyslexia. In addition, for all identified connections, there were no significant differences between the TDC groups and the TA group (Figure 7), indicating that either they are not developmentally sensitive, or they are mature prior to age 7 (but see [39] for developmental differences for brain-behavior relationships with respect to L.FFG-R.MPFC iFC).

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