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Children with dyslexia show cortical hyperactivation in response to increasing literacy processing demands.

Morken F, Helland T, Hugdahl K, Specht K - Front Psychol (2014)

Bottom Line: In the analyses, six regions showed an interaction effect between group and condition in a factorial ANOVA.The six regions further grouped into three patterns, which are discussed in terms of processing demands, compensatory mechanisms, orthography and contextual facilitation.We conclude that the observed hyperactivation is chiefly a result of compensatory activity, modulated by other factors.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological and Medical Psychology, University of Bergen Bergen, Norway.

ABSTRACT
This fMRI study aimed to examine how differences in literacy processing demands may affect cortical activation patterns in 11- to 12-year-old children with dyslexia as compared to children with typical reading skills. Eleven children with and 18 without dyslexia were assessed using a reading paradigm based on different stages of literacy development. In the analyses, six regions showed an interaction effect between group and condition in a factorial ANOVA. These regions were selected as regions of interest (ROI) for further analyses. Overall, the dyslexia group showed cortical hyperactivation compared to the typical group. The difference between the groups tended to increase with increasing processing demands. Differences in cortical activation were not reflected in in-scanner reading performance. The six regions further grouped into three patterns, which are discussed in terms of processing demands, compensatory mechanisms, orthography and contextual facilitation. We conclude that the observed hyperactivation is chiefly a result of compensatory activity, modulated by other factors.

No MeSH data available.


Related in: MedlinePlus

ROI analyses interaction effects. Y-axes show activation levels. Significant t-tests are marked by *. The typical group is shown as a dotted blue line and the dyslexia group is shown as a solid red line.
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Figure 3: ROI analyses interaction effects. Y-axes show activation levels. Significant t-tests are marked by *. The typical group is shown as a dotted blue line and the dyslexia group is shown as a solid red line.

Mentions: To investigate the effects of increases in literacy processing demand, ROI analyses with repeated measures ANOVA followed by Fisher's LSD and t-tests were performed for the six regions showing an interaction effect of group by condition on the factorial ANOVA, indicating a difference in the way the typical and the dyslexia group handled changes in processing demand. Figure 3 shows an overview of the activation patterns in the different ROI.


Children with dyslexia show cortical hyperactivation in response to increasing literacy processing demands.

Morken F, Helland T, Hugdahl K, Specht K - Front Psychol (2014)

ROI analyses interaction effects. Y-axes show activation levels. Significant t-tests are marked by *. The typical group is shown as a dotted blue line and the dyslexia group is shown as a solid red line.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4273608&req=5

Figure 3: ROI analyses interaction effects. Y-axes show activation levels. Significant t-tests are marked by *. The typical group is shown as a dotted blue line and the dyslexia group is shown as a solid red line.
Mentions: To investigate the effects of increases in literacy processing demand, ROI analyses with repeated measures ANOVA followed by Fisher's LSD and t-tests were performed for the six regions showing an interaction effect of group by condition on the factorial ANOVA, indicating a difference in the way the typical and the dyslexia group handled changes in processing demand. Figure 3 shows an overview of the activation patterns in the different ROI.

Bottom Line: In the analyses, six regions showed an interaction effect between group and condition in a factorial ANOVA.The six regions further grouped into three patterns, which are discussed in terms of processing demands, compensatory mechanisms, orthography and contextual facilitation.We conclude that the observed hyperactivation is chiefly a result of compensatory activity, modulated by other factors.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological and Medical Psychology, University of Bergen Bergen, Norway.

ABSTRACT
This fMRI study aimed to examine how differences in literacy processing demands may affect cortical activation patterns in 11- to 12-year-old children with dyslexia as compared to children with typical reading skills. Eleven children with and 18 without dyslexia were assessed using a reading paradigm based on different stages of literacy development. In the analyses, six regions showed an interaction effect between group and condition in a factorial ANOVA. These regions were selected as regions of interest (ROI) for further analyses. Overall, the dyslexia group showed cortical hyperactivation compared to the typical group. The difference between the groups tended to increase with increasing processing demands. Differences in cortical activation were not reflected in in-scanner reading performance. The six regions further grouped into three patterns, which are discussed in terms of processing demands, compensatory mechanisms, orthography and contextual facilitation. We conclude that the observed hyperactivation is chiefly a result of compensatory activity, modulated by other factors.

No MeSH data available.


Related in: MedlinePlus