Gray's three-arousal model: an empirical investigation

We evaluated the validity of Gray's and Fowles' three-arousal model in two studies of criminal offenders using a continuous motor task involving rewar ds and punishments. Consistent with predictions for the behavioral approach /activation system (BAS), offenders displayed significant (p < 0.00001) inc reases in response time and heart rate (I-IR) from a no-incentive practice phase to a reward-only (experiment I) and active-avoidance (experiment 2) p hase. Trait impulsivity was correlated with the response time index of BAS activation ill experiment 1 but not experiment 2. Consistent with predictio ns for the behavioral inhibition system (BIS), offenders showed a significa nt increase in number of skin conductance responses (SCRs) (p < 0.05) from a reward-only to a mixed-incentive phase in experiment I and a significant increase in SC amplitude to punishment cues in both experiments. Consistent with predictions for the dynamics of the model, participants showed signif icant slowing of response time (p < 0.0001) from reward-only (experiment I) or active avoidance (experiment 2) to mixed-incentive phases despite showi ng an initial tendency toward response facilitation to the onset of the pun ishment cue signifying the beginning of the mixed-incentive phases. Partici pants also showed significant (p < 0.002) decreases in HR between these pha ses in both studies, but this effect was only evident on trial I, The BIS-i nfluenced response time and HR indices were significantly (p < 0.05) correl ated with anxiety in experiment 1, but unexpectedly, anxiety was not correl ated with SC indices of the BIS in either study, Although much of the data support the validity of the Gray/Fowles model, particular findings suggest that further refinement of this theory is indicated, (C) 2000 Elsevier Scie nce Ltd. All rights reserved.