Schizophrenia Bulletin vol. 34 no. 5 pp. 819–834, 2008 doi:10.1093/schbul/sbn071 Advance Access publication on June 25, 2008 Emotional Response Deficits in Schizophrenia: Insights From Affective Science Ann M. Kring1,2 and Erin K. Moran2 Many factors have contributed to the relatively recent 2Department of Psychology, University of California, Berkeley, CA increaseinresearchonemotioninschizophrenia,butacen- trally important factor has been the development and adoption of methods and theories in basic affective sci- Our understanding of the emotional features of schizophre- ence.Emotionwaslongconsideredtobethe‘‘blacksheep’’ nia has benefited greatly from the adoption of methods and of the family with respect to behaviors that could be em- theory from the field of affective science. This article covers pirically studied, but pioneering work by investigators basic concepts and methods from affective science on the psy- such as Paul Ekman and Carroll Izard in the 1960s paved chological and neural mechanisms contributing to emotions the way for emotion research to become not only well ac- and reviews the ways in which this research has advanced our cepted and integrated into psychology and neuroscience understanding of emotional response deficits in schizophre- but also as a discipline in its own right. Indeed, the explo- nia. We review naturalistic studies and elicitation studies sion of brain imaging techniques has further advanced our that evoke emotion responses among participants, including understanding of how emotion works at the level of the emotion expression, experience, and autonomic physiology. brain, and taken together, we now know a great deal about emotional behavior and its neural underpinnings (see We also consider how these emotion response mea- 4 5 sures correspond to schizophrenia symptoms, and we focus Barrett et al and Wager et al for recent reviews). particular attention on the issue of sex differences in emotional responding and how this may influence our under- Constraining Emotion and Emotion Disturbances in standing emotional functioning among individuals with Schizophrenia schizophrenia. From the affective science perspective, emotions are com- Key words: schizophrenia/emotion experience/ plex systems that have developed through the course of emotion expression/affect human evolutionary history to prepare organisms to act in response to a number of environmental stimuli and Theoretical and clinical writings in schizophrenia are re- challenges. Thus, under most circumstances, emotions serve a number of important intra- and interpersonal plete with rich descriptions of emotional disturbance that 6–9 date back to the early 20th century.1,2 For example, Ble- functions, a point which amplifies the notion that emo- uler noted tions are adaptive and not simply the bane of our rational or ‘‘reasoned’’ existence. The functions of emotion in per- ‘‘Occasionally, a patient will maintain that he has a marked sons with schizophrenia are comparable to those without and powerful affect, whereas the observer can note none or schizophrenia7,10; however, emotion disturbances in another type of affect than that which the patient professes schizophrenia can interfere with the achievement of these to feel (3(p51)).’’ important emotion-related functions. For example, This apparent disconnect between the outward display of a schizophrenia patient’s absence of facial expressions emotion and feeling that Bleuler referred to has now been may evoke negative responses from others,11 thus nega- confirmed empirically, and in the present article, we re- tively impacting social relationships and interactions.12 view the literature on emotion responding in schizophre- Emotional responses are typically considered to be nia and argue that the adoption of the affective science comprised of multiple components, including (but not approach has greatly advanced our understanding of limited to) expression, experience, and physiology. The the nature of emotion disturbances. extent to which these emotion components correspond with one another or cohere remains a topic of debate.13–15 Functionalist accounts of emotion suggest that coherence 9 1 among components is adaptive, yet the empirical data To whom correspondence should be addressed; Department of 13,16 Psychology, 3210 Tolman Hall, University of California, Berkeley, supporting coherence is mixed. CA 94720-1650; tel: 510-643-1560, fax: 510-642-5293, e-mail: The terms ‘‘affect’’ and ‘‘emotion’’ are often used in- [email protected]. terchangeably in the schizophrenia literature, but from Ó The Author 2008. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: [email protected]. 819 A. M. Kring & E. K. Moran the affective science perspective, there are important (1) studies that elicit(evoke, generate) emotion responses conceptual and empirical distinctions between the terms. from participants (eg, presenting emotionally evocative Specifically, affect is most often used in reference to feel- film clips and assessing reports of emotional experience), ing states, whereas emotion is used in reference to mul- (2) studies that assess perception(recognition) of affective tiple components (only one of which is a feeling state). stimuli (eg, presenting pictures of faces and assessing ac- By contrast, in the schizophrenia literature, affect is curacy of emotion expression identification), (3) natural- sometimes used to refer to a feeling state and sometimes istic studies that assess emotion in participants’ natural used to refer to the expression of emotion (eg, flat affect). environments (eg, assessing emotional experience in con- It does not seem likely that the affective science perspec- text of daily life several times a day for several days, ob- tive on terminology will take hold in the schizophrenia serving emotional behavior in an inpatient setting); (4) literature, nor is it clear that it need be adopted. However, studies that assess trait or individual differences in emo- it would be of benefit to the field to forego broad and tion components (eg, collecting self-report measures of uninformative terms such as ‘‘affect processing’’ or anhedonia or emotional expression), and (5) studies ‘‘emotion processing’’ (see also Herbener et al17). These that assess the impact of emotion on some other process terms are used to describe anything from the study of (eg, assessing how the emotional valence of words emotion facial expressions following the presentation impacts the ability to recall the words). Of course, these of emotionally evocative film clips to the reading of emo- are not rigid demarcations, and many studies combine tional words. Not only are these tasks different, but they more than one of these methods. For example, a study also recruit different brain regions in the service of per- may present emotionally evocative pictures and assess forming them5 and the behavioral outputs from these facial expression responses to the pictures and then later tasks are linked to different aspects of schizophrenia, in- test memory for the previously viewed pictures. Moreover, cluding specific symptoms and functional outcomes. Per- studies designed to elicit emotion will likely require rec- haps reflecting the fact that studies of emotion in ognition of the affective significance of the stimulus to schizophrenia are fewer and more recent than studies engender a response, and studies designed to assess the of cognitive deficits, such terminological imprecision perception of affective stimuli may well elicit an emotional might be expected. Indeed, ‘‘information processing’’ response.5 Nevertheless, it can be helpful to keep in mind was long used to describe different studies of cognition the goals and methods of the study with respect to what in schizophrenia until the translation of cognitive neuro- aspect(s) of emotion is being manipulated and assessed. science theory and methods to schizophrenia research It is also helpful to distinguish the types of dependent pointed to the importance of more clearly demarcating variables or measures of emotion included in particular the specific type of cognition (eg, episodic memory, cog- studies. Studies that elicit emotion are typically interested nitive control) under investigation, thus rendering the use in assessing emotional responses, such as facial expres- of the more vague term less likely (As a rough index of the sion, experience, physiology, or brain activation. Studies decline in the use of the term ‘‘information processing,’’ that assess perception or recognition of affective stimuli a PubMed search for ‘‘information processing and are typically interested in assessing accuracy of identifi- schizophrenia’’ in the title yielded 106 articles dating cation or discrimination, but these studies also may assess back to 1971. Three-quarters of these articles were pub- responses to these stimuli (eg, brain activation, auto- lished prior to the year 2000. A similar search in PsychIn- nomic physiology). Naturalistic studies often assess fo yielded 193 articles dating back to 1964; 80% of these reports of emotional experience in context (eg, when at were published prior to the year 2000.). As the current home, when with friends). Studies that assess emotion’s review will point out, there are important distinctions impact on some other process typically assess the other in which components of emotional response are (or are process of interest. For example,