Table 3.

SES × age interactions in language-related regions of interest

ROI	Factors	Model R2	Beta (sig)
LSTG	Age	0.549	−2.633 (0.010)
	Total cortical volume		0.734 (2.6 × 10 −8 )
	Average parent education		−1.396 (0.010)
	Parent education × age		2.516 (0.012)
LIFG	Age	0.482	−2.820 (0.013)
	Total cortical volume		0.554 (3.7 × 10 −5 )
	Average parent education		−1.217 (0.042)
	Parent education × age		2.769 (0.014)

Note: LSTG = Left superior temporal gyrus; LIFG = Left inferior frontal gyrus. Models of effects of SES on region of interest (ROI) volume, controlling for age and total cortical volume, and including SES × age interactions. Sample is restricted to the 44 children whose parent education ranged from 11 to 17.5 years, to reduce the confound between age and parent education seen in the full sample. Parent education × child age interactions are observed in the volume of the left superior temporal gyrus and left inferior frontal gyrus, suggesting that the effects of SES in these regions are not constant at different ages. This is illustrated in Figure 3. No SES × age interactions were found in other ROIs.