ON THE BROAD APPLICABILITY OF THE AFFECTIVE CIRCUMPLEX: Representations of Affective Knowledge Among Schizophrenia Patients

Studies of affective experience are guided by the assumption that the structure of affect generalizes across people. Yet this assumption has not been tested among educationally and economically diverse community residents or among individuals with psychopathology. This study explicitly examined the broad applicability of the valence-arousal circumplex and whether schizophrenia patients and nonpatients have comparable knowledge structures of affective phenomena. Patients and nonpatients completed similarity ratings of 120 pairs of affect words. Similarity judgments were analyzed separately for each group using a multidimensional scaling procedure, and solutions were compared. Results revealed the same two-dimensional valence-arousal solution for schizophrenia patients and nonpatients, although there were subtle differences between the groups. These findings provide additional evidence that the circumplex model is a useful formalism for representing affective phenomena across diverse populations, and they bolster confidence in existing interpretations of schizophrenia patients’ reports of affective experience. Human interaction with the world, whether disordered or normative, is guided by a ubiquitous system: affect. Across many domains of psychological research, investigators have utilized dimensional models of affect to ground their inquiries. Dimensional models of affect have a long history in psychology. A dimensional approach was introduced by Wundt’s (1912/1924) introspections, and several dimensional models exist in modern-day accounts of affect (e.g., Cacioppo, Gardner, & Berntson, 1999; Lang, 1995; Watson & Tellegen, 1985). One of the most well-replicated models is the valence-arousal affective circumplex (Feldman Barrett & Russell, 1998; Remington, Fabrigar, & Visser, 2000; Russell, 1980; Russell & Feldman Barrett, 1999). Valence refers to the hedonic quality (pleasure or displeasure) of, and arousal (or activation) to the felt activation associated with, affectrelated stimuli. The valence-arousal structures have been replicated across cultures, people of different ages, and different types of affective stimuli, and have been used to organize biological measurements related to emotion (e.g., Lang, 1995). Given this replicability, the affective circumplex has been thought of as a multipurpose, mathematical formalism for representing affective phenomena as combinations of these two independent dimensions. When they are derived from similarity ratings of affect words, valence and arousal dimensions are thought to represent the basic aspects of semantic knowledge about affect (an interpretation consistent with the semantic differential work by Osgood, Suci, & Tannenbaum, 1957). Although not all information about emotion is captured by the circumplex model, it is a useful tool for representing the core features of declarative knowledge about affect-related stimuli. Despite the evidence supporting its broad replicability, the valencearousal model, like so many other phenomena, has not been verified in populations often neglected in psychological research. Indeed, very little research has verified the applicability of the affective circumplex among individuals with lower educational attainment and socioeconomic realization than the college students so often used in research. It would be tempting to assume that the model is robust and generalizable across many populations, were it not for the fact that contextual and sampling variables have a profound impact on research findings, often in the most unexpected ways. Moreover, despite the burgeoning interest in affective disturbances associated with mental disorders (Kring & Bachorowski, 1999), no research has examined whether the affective circumplex applies to mentally disordered populations, even though such applicability is often assumed. This issue is particularly germane to the study of emotion disturbances in schizophrenia. AFFECTIVE EXPERIENCE IN SCHIZOPHRENIA Consistent with historical observations (e.g., Bleuler, 1911/1950), a number of recent studies have found that, compared with nonpatients, schizophrenia patients exhibit very few outward displays of emotion despite reporting equivalent or greater amounts of experienced emotion (e.g., Berenbaum & Oltmanns, 1992; Kring & Earnst, 1999; Kring & Neale, 1996). Further, there has been remarkable consistency across studies and laboratories with respect to self-reported affective experience; specifically, patients report experiencing more unpleasant emotion in response to emotionally evocative stimuli than do nonpatients (Kring & Earnst, 1999, in press). Despite the consistency in findings, two fundamental issues remain unresolved. First, many researchers question whether schizophrenia patients can accurately complete a self-report measure of their affective experience, presumably because their cognitive impairments may preclude them from doing so. Second, the valence-arousal circumplex has not been explicitly identified in schizophrenia patients, although it is often assumed to apply. These two issues are intertwined, insofar as inferences about the veracity of schizophrenia patients’ reports of their experience are based on the untested assumption that schizophrenia patients’ representations of affective phenomena are faulty. Thus, the more fundamental question of how patients represent affective knowledge is perhaps the most important question to address. An investigation of whether schizophrenia patients’ affective knowledge differs significantly from nonpatients’ provides a necessary platform for understanding and interpreting affect-related phenomena in schizophrenia, especially if declarative knowledge about affect influences how people represent their own affective experience and process affect-related stimuli (Feldman, 1995; Feldman Barrett, 1998, 2001; First authorship is shared between Ann Kring and Lisa Feldman Barrett. Address correspondence to Ann Kring, Department of Psychology, 3210 Tolman Hall, University of California, Berkeley, Berkeley, CA 94720, e-mail: kring@socrates.berkeley.edu, or to Lisa Feldman Barrett, Department of Psychology, 427 McGuinn Building, Boston College, Chestnut Hill, MA 02167, e-mail: barretli@bc.edu. PSYCHOLOGICAL SCIENCE Affect in Schizophrenia 208 VOL. 14, NO. 3, MAY 2003 Russell, 1980). For example, finding that schizophrenia patients possess the same knowledge representations of affective phenomena as nonpatients would justify continued examination and comparison of patients’ and nonpatients’ reports of their felt experience within a common frame of reference. Early attempts to examine semantic knowledge about affect in schizophrenia focused on the idea that affective words interfered with other types of cognitive processing, thereby exacerbating the thinking disturbance often observed in schizophrenia (e.g., Lebow & Epstein, 1963), although empirical investigations failed to support this notion (Chapman & Chapman, 1975; Chapman, Chapman, & Daut, 1974). In another line of research, two studies explicitly examined schizophrenia patients’ similarity judgments of affective words (Neufeld, 1975, 1976) using an individual difference multidimensional scaling (MDS) technique (INDSCAL). Overall, patients’ similarity judgments were more similar than dissimilar to nonpatients’ judgments, and tended to yield valence and arousal dimensions (along with a dominance-type dimension). It is difficult to generalize broadly from these two studies, however, because of methodological considerations. First, neither study adequately sampled all combinations of valence and arousal, so the replicability and interpretability of the resulting dimensional solution is limited. Second, similarity judgments from nonpatient control participants were combined with the judgments from schizophrenia patients to produce one general solution. It would be important to analyze the judgments for each group separately to test their congruence before combining them into a single dimensional display. OVERVIEW OF THE PRESENT STUDY The present study addressed two questions: (a) Does the affective circumplex extend to diverse populations? (b) More specifically, do patients with schizophrenia possess the same representations of affect knowledge as do individuals without schizophrenia? To address these questions, we had schizophrenia patients and nonpatient community residents rate the similarity of affect words. We included a comprehensive and representative sample of terms from the affective circumplex, thus allowing for an unbiased analysis of the dimensional structure. Because similarity judgments are thought to be an index of mental structure, and dimensional analyses of these ratings produce dimensions that represent the underlying attributes or properties of that mental structure (Davison, 1983; Shepard, 1962, 1974, 1980), comparing solutions across groups allowed us to determine whether schizophrenia patients and nonpatients have comparable knowledge structures of affective phenomena, and whether these structures are identifiable as the valence-arousal circumplex.