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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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Locations of seed ROIs.Seeds are presented as overlaid black circles. MNI coordinates of these seeds are provided in Table 2. L.IOC = Left Inferior Occipital Gyrus, L.FFG = Left Fusiform Gyrus, L.STG = Left Superior Temporal Gyrus, L.TPJ = Left Temporoparietal Junction, L.IPS = Left Inferior Parietal Lobule, L.IPS = Left Intraparietal Sulcus, L.PCG = Left Precentral Gyrus, L.SMA = Left Supplementary Motor Area, L.IFGop = Left Inferior Frontal Gyrus pars Opercularis, L.IFGtr = Left Inferior Frontal Gyrus pars Triangularis, L.MFG = Left Middle Frontal Gyrus, L.THAL = Left Thalamus.
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pone-0055454-g003: Locations of seed ROIs.Seeds are presented as overlaid black circles. MNI coordinates of these seeds are provided in Table 2. L.IOC = Left Inferior Occipital Gyrus, L.FFG = Left Fusiform Gyrus, L.STG = Left Superior Temporal Gyrus, L.TPJ = Left Temporoparietal Junction, L.IPS = Left Inferior Parietal Lobule, L.IPS = Left Intraparietal Sulcus, L.PCG = Left Precentral Gyrus, L.SMA = Left Supplementary Motor Area, L.IFGop = Left Inferior Frontal Gyrus pars Opercularis, L.IFGtr = Left Inferior Frontal Gyrus pars Triangularis, L.MFG = Left Middle Frontal Gyrus, L.THAL = Left Thalamus.

Mentions: We examined functional connectivity associated with 12 regions of interest (ROIs), including 11 regions that had been derived from meta-analyses of reading in children [51] and adults [50] and validated in a previous R-fMRI study [39]. One additional region, the left inferior parietal lobule (L.IPL), was added based on the most recent meta-analysis of children with dyslexia [52]; the remainder of the regions in the meta-analysis were already included in our previous work [39]. The 12 ROIs in the current study were: 1) left inferior occipital gyrus (L.IOG), 2) left posterior fusiform gyrus (L.FFG), 3) left posterior superior temporal gyrus (L.STG), 4) left temporoparietal junction (L.TPJ), 6) left inferior parietal lobule (L.IPL), 7) left intraparietal sulcus (L.IPS), 8) left dorsal precentral gyrus (L.PCG), 9) left supplementary motor area (L.SMA), 8) left inferior frontal gyrus pars opercularis (L.IFGop), 10) left inferior frontal gyrus pars triangularis (L.IFGtr), 11) left middle frontal gyrus (L.MFG), and 12) left thalamus (L.THAL). Each ROI was a spherical seed (6 mm radius in 2 mm standard space) [39], centered on the MNI coordinates listed in Table 2. Figure 3 shows the spatial locations of the seeds.


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)

Locations of seed ROIs.Seeds are presented as overlaid black circles. MNI coordinates of these seeds are provided in Table 2. L.IOC = Left Inferior Occipital Gyrus, L.FFG = Left Fusiform Gyrus, L.STG = Left Superior Temporal Gyrus, L.TPJ = Left Temporoparietal Junction, L.IPS = Left Inferior Parietal Lobule, L.IPS = Left Intraparietal Sulcus, L.PCG = Left Precentral Gyrus, L.SMA = Left Supplementary Motor Area, L.IFGop = Left Inferior Frontal Gyrus pars Opercularis, L.IFGtr = Left Inferior Frontal Gyrus pars Triangularis, L.MFG = Left Middle Frontal Gyrus, L.THAL = Left Thalamus.
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Related In: Results  -  Collection

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

pone-0055454-g003: Locations of seed ROIs.Seeds are presented as overlaid black circles. MNI coordinates of these seeds are provided in Table 2. L.IOC = Left Inferior Occipital Gyrus, L.FFG = Left Fusiform Gyrus, L.STG = Left Superior Temporal Gyrus, L.TPJ = Left Temporoparietal Junction, L.IPS = Left Inferior Parietal Lobule, L.IPS = Left Intraparietal Sulcus, L.PCG = Left Precentral Gyrus, L.SMA = Left Supplementary Motor Area, L.IFGop = Left Inferior Frontal Gyrus pars Opercularis, L.IFGtr = Left Inferior Frontal Gyrus pars Triangularis, L.MFG = Left Middle Frontal Gyrus, L.THAL = Left Thalamus.
Mentions: We examined functional connectivity associated with 12 regions of interest (ROIs), including 11 regions that had been derived from meta-analyses of reading in children [51] and adults [50] and validated in a previous R-fMRI study [39]. One additional region, the left inferior parietal lobule (L.IPL), was added based on the most recent meta-analysis of children with dyslexia [52]; the remainder of the regions in the meta-analysis were already included in our previous work [39]. The 12 ROIs in the current study were: 1) left inferior occipital gyrus (L.IOG), 2) left posterior fusiform gyrus (L.FFG), 3) left posterior superior temporal gyrus (L.STG), 4) left temporoparietal junction (L.TPJ), 6) left inferior parietal lobule (L.IPL), 7) left intraparietal sulcus (L.IPS), 8) left dorsal precentral gyrus (L.PCG), 9) left supplementary motor area (L.SMA), 8) left inferior frontal gyrus pars opercularis (L.IFGop), 10) left inferior frontal gyrus pars triangularis (L.IFGtr), 11) left middle frontal gyrus (L.MFG), and 12) left thalamus (L.THAL). Each ROI was a spherical seed (6 mm radius in 2 mm standard space) [39], centered on the MNI coordinates listed in Table 2. Figure 3 shows the spatial locations of the seeds.

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