Fig. 6

Increased delta power correlates with decreased developmental quotient on the Mullen Scales of Early Learning in girls with Rett syndrome. Spearman’s rho correlations (with fitted line) between frontal delta power and developmental quotient on the Mullen Scales of Early Learning (MSEL) in the receptive language (a), visual reception (b), expressive language (c), and fine motor (d) domains. Developmental quotients were calculated by dividing developmental age as predicted by MSEL scores in each domain by chronological age (in months)