These childhood-to-adolescent years also mark advancement through puberty and its plethora of sex-specific hormonal changes that influence physical growth and maturity not only in physiognomy but also in brain morphology. Despite the likely linking of pubertal and brain structural development, few MRI studies provide information about pubertal staging at times of study (cf., Blakemore et al.). Those that have used schedules of pubertal development, such as Tanner staging (Tanner, 1962), or direct measurement of sex hormones report mixed results, with some [MRI: (Neufang et al., 2009; Peper et al., 2009a)] but not others [sleep electrophysology: (Feinberg et al., 2006)] finding staging or hormonal levels to be predictive of changes in brain structure or presumed associated function. Whether brain structural changes are great enough for detection with conventional MRI over about half-year intervals in young adolescents has not been tested and therefore never linked to active pubertal advancement.
