Cohen’s d effect sizes for the reading disability group comparisons with and without cases exhibiting evidence of OWL LD based on combined verbal comprehension and total gray matter volume values that were below the combined percentile cutoffs
Left OFC | Left STS | Right CrbH | |
---|---|---|---|
No cases removed (N=255) | 0.34 | 0.37 | 0.24 |
Cases <15th/25th percentile removed (N=245) | 0.31 | 0.33 | 0.18 |
Cases <25th percentile removed (N=243) | 0.28 | 0.29 | 0.16 |
Cases <30th percentile removed (N=240) | 0.28 | 0.26 | 0.15 |
Cases <37th percentile removed (N=234) | 0.28 | 0.27 | 0.12 |
The 15th/25th percentile thresholds for classification of OWL LD were used for verbal comprehension and total gray matter volume, respectively. These thresholds were chosen based on the size of group differences reported in the literature for those variables. Otherwise, the same percentile threshold was used for both variables. The Cohen’s d values were calculated based on the mean and SD of the ROI gray matter volumes for each reading disability group.