Statistical Analyses
As explained above, we controlled for age in the analyses. To test the
prediction that the HD group would demonstrate greater ERN during
simulated discarding decisions relative to emotionally neutral decisions
as compared to the control groups, we used a 3 (group) x 2 (task: ERN
during the discarding task vs. neutral task) mixed analysis of
covariance (ANCOVA), controlling for age. To test the prediction that
the HD group would demonstrate greater right vs. left alpha asymmetry,
we used 1-way ANCOVA, controlling for age. For our prediction that the
HD group would demonstrate greater psychophysiological activity during
the simulated discarding task relative to the neutral task compared to
the control groups, we used 3 (group) x 2 (task: ETCO2,
SCL, HRV, and HR during the discarding task vs. neutral task) mixed
ANCOVAs, controlling for age. Finally, we used hierarchical multiple
regression to test the prediction that the ERN during discarding
decisions would predict SI-R scores, controlling for age.