Table 2:

Parameter estimates from piecewise linear regression analyses and change-point age.

	Rate of Initial Change					Rate of Subsequent Change
	Estimate	Lower Bound	Upper Bound	t-value	Change Point	Estimate	Lower Bound	Upper Bound	t-value
PC1	−263.3	−272.0	−254.7	−59.52	17.7	−32.6	−36.3	−28.9	−17.18
PC2	−69.5	−73.1	−65.8	−37.26	19.5	−5.1	−7.4	−2.7	−4.16
PC3	−142.5	−148.2	−136.9	−49.47	18.6	−12.6	−15.4	−9.9	−9.00
PC4	−422.2	−436.8	−407.6	−56.64	17.2	−71.0	−77.0	−64.9	−22.97
PC5	−269.9	−280.5	−259.4	−50.07	16.1	−22.7	−25.9	−19.6	−14.19
PC6	−209.8	−219.7	−199.8	−41.45	16.4	−11.9	−16.2	−7.5	−5.37

Note: Parameter estimates represent the amount of change in component scores (time-frequency energy) for a year change in chronological age (independent of effects of sex), and these are provided separately for initial change and change after the inflection point (knot), along with lower and upper bounds of 95% confidence intervals. Both age effects are associated with 4027 df.