Table 2: Tests for the effect of potential confounds on delay.

From: Age-related delay in visual and auditory evoked responses is mediated by white- and grey-matter differences

 Age versus delayAge versus acuityDelay versus acuityDelay versus acuity
Cov=age
Age versus delay
Cov=acuity
N
Auditory cumulative0.37***−0.46***−0.21***−0.050.31***575
Visual constant0.32***0.43***−0.14**−0.000.30***524
  Age versus ampDelay versus ampDelay versus amp
Cov=age
Age versus delay
Cov=amp
 
Auditory cumulative-0.20***0.06−0.020.37***577
Visual constant-0.07*−0.03−0.010.32***526
  Age versus offsetDelay versus offsetDelay versus offset
Cov=age
Age versus delay
Cov=offset
 
Auditory cumulative 0.13**−0.16***−0.23***0.41***577
Visual constant 0.30***0.09−0.010.31***526
  Age versus RMSEDelay versus RMSEDelay versus RMSE
Cov=age
Age versus delay
Cov=RMSE
 
Auditory cumulative 0.070.060.030.37***577
Visual constant −0.13**−0.09*−0.050.33***526
  1. Partial rank correlations (Spearman’s Rho) demonstrating that the age versus delay relationships observed in the main results section are not accounted for by visual or auditory acuity, age-related changes in amplitude scaling (Amp), amplitude offset (Offset) or root mean square error (RMSE) of fit. Column 2 shows the relationship between age and the potential confounding variable (for example, auditory/visual acuity). Column 3 shows the relationship between evoked response delay and the confounding variable. Column 4 shows the relationship between delay and the confounding variable while controlling for age. Column 5 shows the relationship between age and delay while controlling for the confounding variable. In all cases, except for amplitude offset, controlling for age abolishes the relationship between delay and the confounding variable. In all cases, controlling for the confounding variable has very little effect on the age-delay relationship. Auditory acuity measures were not available for 2 participants, who were excluded from the above analysis. * P<0.05, **P<0.01, ***P<0.001.