| Heller (1993) has posited a central role for parietotemporal regions of the right hemisphere in the modulation of autonomic and behavioral arousal in emotional states. Her model addresses two dimensions of emotion with special clinical significance---depression and anxiety---by linking depression with a decrease and anxiety with an increase in right hemisphere arousal. Heller et al. (1995) tested the model in undergraduates classified into either high- or low-depression and high- or low-trait-anxiety subgroups. The dependent measure was the Chimeric Faces Task, or CFT (Levy et al., 1983). On this task, most individuals show a left-hemispace bias, seen as reflecting greater right-hemisphere arousal. The results supported the model: depression was related to weaker bias, anxiety to a stronger bias.;The aim of the current study was to test the reliability of Heller et al.'s (1995) results, and to assess contributions to CFT scores of anxiety subtypes---state vs. trait. Along with the CFT, 357 undergraduates completed self-report measures of depression, state anxiety, and trait anxiety. The study also compared Heller's model with a model proposed by Davidson (1992) that shifts the focus from parietotemporal to frontal regions and links approach and avoidance behaviors to left and right frontal regions, respectively. Approach and withdrawal behaviors were measured by a test of coping styles (engagement vs. disengagement) in stressful situations.;The results did not support Heller's model: trait anxiety and depression were unrelated to either strength or direction of hemispace bias, whereas state anxiety was related to a weaker, rather than stronger, left-hemispace bias. Likewise, in subjects high in depression and trait anxiety and in subjects high in state anxiety and trait anxiety, proportionately more, rather than fewer, had right-hemispace biases compared to controls, implying greater left- than right-hemisphere arousal. The only supported prediction was the one derived from Davidson's model, namely, that the tendency to disengage from stressful situations was related to a stronger left hemispace bias. This was true, however, only for subjects high in trait anxiety.;Because state anxiety was inversely, rather than directly, related to CFT scores, the data were re-examined to better understand this relation. First, on the possibility that "state anxiety" contains a mix of subtypes, a principle components analysis was performed on this measure. This analysis revealed four factors. Next, a hierarchical regression was performed to compare the factors' relation to CFT scores. Only two factors were related to bias---those best described as "cognitive worry" and "free-floating anxiety." For both, higher levels were related to weaker left-hemispace bias.;Together, the results suggest that in state-anxious persons, only cognitive worry and free-floating anxiety are associated with decreased right-hemisphere arousal, whereas in trait-anxious persons, disengagement is associated with increased right-hemisphere arousal. The results thus do not support Heller's model but suggest how its with Davidson's might have more explanatory power. Integration, however, will require making meaningful distinctions among anxiety subtypes. |
