TABLE 7.

(a) Direct effects of experiential scales on task RT (ms) performance. (b) Magnitude of indirect effect of socioeconomic variables on WM updating cost reaction time through cognitive enrichment subscale of HOME-SF

	WM response task		WM feature task		WM dimension task
(a)	Updating	Maintenance	Updating	Maintenance	Updating	Maintenance
HOME-SF cognitive enrichment	33.80*	22.29	6.14***	1.25	36.84	1.10
HOME-SF routine	−14.76	19.39	4.45	−5.99	35.32	2.72
HOME-SF parental closeness	−6.40	16.98	12.38	16.40	−49.45	−31.57
HOME-SF restrictive parenting	−2.87	3.66	26.99	−19.17	−39.56	−11.14
HOME-SF parental monitoring	26.37	−7.16	4.72	−4.84	−7.61	−1.87
HOME-SF supportive parenting	−16.85	5.94	−3.63	1.73	−31.42	27.24
LEC # Negative life events	−1.26	1.08	−14.65	3.26	−1.13	2.35
	WM response task, updating			WM feature task, updating
(b)	Total	Direct	Indirect	Total	Direct	Indirect
Household income in dollars	0.04	−0.42	0.45**	0.31	−0.37	0.67**
Income-to-needs ratio	0.29	−1.72	11.02	8.23	−7.82	16.06**
Parent 1 Education in years	2.29	−1.67	3.96	−4.48	−12.88	8.40*
Parent 2 Education in years	−2.54	−4.85	2.31	3.56	−0.55	4.11
Parent 1 Occupation level	15.07	3.18	11.89	1.59	−7.17	17.76
Parent 2 Occupation level	−3.82	−9.73	5.91	23.38	15.32	8.07

Notes. HOME-SF, Home Observation for Measurement of the Environment-Short Form; LEC, Life Events Checklist; WM, working memory.

Cells represent beta coefficients predicting task reaction time in regression models with 5,000 bootstrap replications, controlling for age of child. Missing data accounted for with maximum-likelihood maximum variation.

“Updating” represents cost of updating higher order rules into WM and “Maintenance” represents cost of increasing alternatives for action at the same level. “Updating” is calculated as difference between Level 1 and Level 2 (Block 2 − Block 1). “Maintenance” is calculated as difference between Level 2 and Level 4 (Block 4 − Block 2).

^*p < 0.05;

^**p < 0.01;

^***p < 0.001.