115
Direct comparison of the mean HR change during the
shock and reward conditions was also examined by employing a
repeated measures analyses of variance (ANOVA) using group
(LH, LH NCS, RH, RH NCS) as the between subject factor and
condition (shock minus no-shock and reward minus no-reward)
as the within subject factor. There was no significant
difference within the two tasks [F(1,43) = .237, P = .629]
or between groups [F(3,43) = 1.060, P = .376]. The group by
task interaction was also not significant [F(3,43) = .400, P
=.754]. The mean bpm change from baseline for each group
are as follows: LHD mean=.032, sd=2.02; LH NCS mean=.343,
sd=.820; RHD mean=-.177, sd=2.012; RH NCS mean=.435,
sd=1.439). The ANOVA table, Table C-52, is presented in
Appendix C.
Heart rate Dl, Al, and D2 values for shock task were
compared to the values for reward task by subtracting the
control values from the stimulus values for each subject for
each trial block. These values were compared using a
repeated measures analysis of variance for each variable.
The between subject factor was group (LHD, LH NCS, RHD, RH
NCS) and the within subject factor was task (shock minus
shock-control and reward minus reward-control). There were
no significant differences between the shock and reward
conditions for any of the three variables. The ANOVA
tables, Table C-53, C-54, C-55, are presented in Appendix C.