Abstract
Depression is a highly prevalent mood disorder that impairs a person’s social skills and also their quality of life. Among other problems depressed individuals exhibit a negative bias in the perception of others’ facial emotional expressions compared to non-depressed controls, and the extent of this bias is associated with a poorer prognosis. However, to date, little is known about the mechanisms that may account for this bias. The aim of this thesis was to clarify the nature of the association between depression and emotion perception. In addition, the possibility of rumination as an underlying mechanism that might explain the effects of depression on emotion perception was investigated. Specifically, it was proposed that rumination—an analytic type of self-focused attention often co-occurring with depression—may help explain increased sensitivity to emotional expressions. Study 1 provided an initial, correlational, test of the associations among depressive symptoms, rumination and perceived emotion perception which revealed that both depression and rumination are, independently and interactively, predictive of subjective emotion recognition skills. Study 2 further investigated the causal direction of these relationships, and participants’ objective skill at distinguishing emotions, in an experimental design. Affect and rumination were manipulated independently in the laboratory and their impact on the participants’ judgments of emotional expressions differing in intensity was measured. Results showed that mood and rumination interact to produce greater contrast between different level of emotional intensities, with the greatest contrast resulting from a combination of sad mood and ruminative thought. Study 3 examined a mediating mechanism of the contrast effects in Study 2, namely that negative mood and/or rumination produce more “concrete” (as opposed to “abstract”) thinking, which in turn lead to greater contrast between emotional intensities. Results showed, as in Study 2, that sad mood and rumination had a joint effect on construal level, such that only when participants were both sad and ruminating did construal level shift from baseline. In Study 4, participants’ level of construal was manipulated experimentally and their emotion perception evaluated using Study 2’s emotion perception task. Results indicated that construal level was sufficient to produce the contrast effects observed in ruminators in Study 2. Participants manipulated to think concretely reported greater differences between high and low-intensity emotions and, again, this effect was stronger for those in a negative affective state (i.e., dysphorics). Overall, these findings suggests that effects of depression on emotion perception may be due to the particular confluence of negative mood and rumination, which together produce a highly concrete approach to the stimuli. These findings have implications for both the emotion perception and rumination literatures, suggesting a mechanism for depressives’ perceptual biases. They may also be extrapolated to other phenomena associated with depression such as negative cognitions regarding the self and dysfunctional appraisal of social events and situations, creating new avenues for clinical intervention.