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Featured researches published by Christian G. Kohler.


Schizophrenia Bulletin | 2010

Facial Emotion Perception in Schizophrenia: A Meta-analytic Review

Christian G. Kohler; Jeffrey B. Walker; Elizabeth A. Martin; Kristin M. Healey; Paul J. Moberg

OBJECTIVES A considerable body of literature has reported on emotion perception deficits and the relevance to clinical symptoms and social functioning in schizophrenia. Studies published between 1970-2007 were examined regarding emotion perception abilities between patient and control groups and potential methodological, demographic, and clinical moderators. DATA SOURCES AND REVIEW: Eighty-six studies were identified through a computerized literature search of the MEDLINE, PsychINFO, and PubMed databases. A quality of reporting of meta-analysis standard was followed in the extraction of relevant studies and data. Data on emotion perception, methodology, demographic and clinical characteristics, and antipsychotic medication status were compiled and analyzed using Comprehensive Meta-analysis Version 2.0 (Borenstein M, Hedges L, Higgins J and Rothstein H. Comprehensive Meta-analysis. 2. Englewood, NJ: Biostat; 2005). RESULTS The meta-analysis revealed a large deficit in emotion perception in schizophrenia, irrespective of task type, and several factors that moderated the observed impairment. Illness-related factors included current hospitalization and--in part--clinical symptoms and antipsychotic treatment. Demographic factors included patient age and gender in controls but not race. CONCLUSION Emotion perception impairment in schizophrenia represents a robust finding in schizophrenia that appears to be moderated by certain clinical and demographic factors. Future directions for research on emotion perception are discussed.


Biological Psychiatry | 2000

Emotion recognition deficit in schizophrenia: association with symptomatology and cognition.

Christian G. Kohler; Warren B. Bilker; Michael Hagendoorn; Raquel E. Gur; Ruben C. Gur

BACKGROUND Previous investigations have found impaired recognition of facial affect in schizophrenia. Controversy exists as to whether this impairment represents a specific emotion recognition deficit when compared with other face recognition control tasks. Regardless of whether the emotion processing deficit is differential, it may uniquely influence other manifestations of schizophrenia. We compared patients and healthy control subjects on computerized tasks of emotion and age recognition. Performances on emotion and age recognition tasks were correlated with cognitive functioning and with symptomatology. METHODS Thirty-five patients with schizophrenia and 45 healthy people underwent computerized testing for emotion and age recognition. Participants were assessed neuropsychologically, and patients were rated for positive and negative symptoms. RESULTS The patients with schizophrenia performed worse than control subjects on emotion and age recognition without differential deficit. In both groups, we found higher error rates for identification of emotion in female faces and for identification of sad versus happy faces. In schizophrenic patients, emotion but not age recognition correlated with severity of negative and positive symptoms. In healthy control subjects, neither task correlated with cognitive functions. In schizophrenic patients, emotion but not age recognition correlated with attention, verbal and spatial memory, and language abilities. CONCLUSIONS This study did not reveal a specific deficit for emotion recognition in schizophrenia; however, our findings lend support to the concept that emotion recognition is uniquely associated in schizophrenia with core symptomatology and cognitive domains.


Neuropsychopharmacology | 2001

Computerized neurocognitive scanning: I. Methodology and validation in healthy people

Ruben C. Gur; J. Daniel Ragland; Paul J. Moberg; Travis Turner; Warren B. Bilker; Christian G. Kohler; Steven J. Siegel; Raquel E. Gur

Neuropsychological testing batteries are applied in neurobehavioral evaluations of brain disorders, including neuropsychiatric populations. They are lengthy, require expert administrators and professional scorers, and are prone to data handling errors. We describe a brief computerized neurocognitive “scan” that assesses similar domains with adequate reliability. The scan and a traditional battery were administered to a sample of 92 healthy individuals (44 men, 48 women) in a counterbalanced order. Both approaches showed a significant “sex-typical” gradient, with women outperforming men in verbal memory relative to spatial tasks. Both methods also yielded similar profiles of sex differences, with the additional computerized measure of face memory showing better performance in women. Age effects were evident for both methods, but the computerized scan isolated the effects to speed rather than accuracy. Therefore, the computerized scan has favorable reliability and construct validity and can be applied efficiently to study healthy variability related to age and gender.


Psychiatry Research-neuroimaging | 2004

Differences in facial expressions of four universal emotions

Christian G. Kohler; Travis Turner; Neal Stolar; Warren B. Bilker; Colleen M. Brensinger; Raquel E. Gur; Ruben C. Gur

The facial action coding system (FACS) was used to examine recognition rates in 105 healthy young men and women who viewed 128 facial expressions of posed and evoked happy, sad, angry and fearful emotions in color photographs balanced for gender and ethnicity of poser. Categorical analyses determined the specificity of individual action units for each emotion. Relationships between recognition rates for different emotions and action units were evaluated using a logistic regression model. Each emotion could be identified by a group of action units, characteristic to the emotion and distinct from other emotions. Characteristic happy expressions comprised raised inner eyebrows, tightened lower eyelid, raised cheeks, upper lip raised and lip corners turned upward. Recognition of happy faces was associated with cheek raise, lid tightening and outer brow raise. Characteristic sad expressions comprised furrowed eyebrow, opened mouth with upper lip being raised, lip corners stretched and turned down, and chin pulled up. Only brow lower and chin raise were associated with sad recognition. Characteristic anger expressions comprised lowered eyebrows, eyes wide open with tightened lower lid, lips exposing teeth and stretched lip corners. Recognition of angry faces was associated with lowered eyebrows, upper lid raise and lower lip depression. Characteristic fear expressions comprised eyes wide open, furrowed and raised eyebrows and stretched mouth. Recognition of fearful faces was most highly associated with upper lip raise and nostril dilation, although both occurred infrequently, and with inner brow raise and widened eyes. Comparisons are made with previous studies that used different facial stimuli.


Neuropsychopharmacology | 2001

Computerized neurocognitive scanning: II. The profile of schizophrenia.

Ruben C. Gur; J. Daniel Ragland; Paul J. Moberg; Warren B. Bilker; Christian G. Kohler; Steven J. Siegel; Raquel E. Gur

Cognitive dysfunction in schizophrenia is well established with neuropsychological batteries, which have assessed multiple domains indicating diffuse deficits especially in processing related to frontotemporal systems. Two studies are reported examining the feasibility of the computerized neurocognitive scan to assess differential deficits in schizophrenia. In Study 1, we tested 53 patients and 71 controls with the traditional and computerized assessments counterbalanced in order. Both showed comparable generalized impairment in schizophrenia with differential deficits in executive functions and memory. The profile was replicated in Study 2 in a new sample of 68 patients and 37 controls, receiving only the computerized scan. The combined sample showed robust correlations between performance on both speed and accuracy measures of the neurocognitive scan and clinical variables, including premorbid adjustment, onset age, illness duration, quality of life, and severity of negative symptoms. These correlations were higher and more prevalent in women than men, who showed correlations predominantly for speed rather than accuracy. Neuroleptic exposure was associated with poorer performance only for speed of memory processing, and in men, this association was seen only for typical neuroleptics. We conclude that the computerized neurocognitive scan can be applied reliably in people with schizophrenia, yielding data that support its construct and criterion validity.


Psychiatry Research-neuroimaging | 2011

Facial emotion perception in depression and bipolar disorder: A quantitative review

Christian G. Kohler; Lauren J. Hoffman; Lucas B. Eastman; Kristin M. Healey; Paul J. Moberg

A considerable body of literature has reported on emotion perception deficits and the relevance of these impairments in persons with depression and bipolar disorder. Fifty-one studies published between 1981-February 2009 were examined regarding emotion perception abilities between patient and control groups, and potential methodological, demographic and clinical moderators. Studies were identified through a computerized literature search of the MEDLINE, PsychINFO, and PubMed databases. The Meta-analysis Of Observational Studies in Epidemiology (MOOSE) standard (Stroup et al., 2000) was followed in the extraction of relevant studies and data. Data on emotion perception, methodology, demographic and clinical characteristics were compiled and analyzed using Comprehensive Meta-Analysis version 2.0 (Biostat, 2005). The meta-analysis revealed a moderate deficit in emotion perception in both bipolar disorder and major depressive disorder, irrespective of task type, diagnosis, age of onset/duration of illness, sex, and hospitalization status. Several factors that moderated the observed impairment include self-reported depression, age at time of testing, and years of education. Emotion perception impairment in bipolar disorder and major depressive disorder represents a moderate and stable deficit that appears to be moderated by a limited number of demographic and clinical factors.


Biological Psychiatry | 2004

A sexually dimorphic ratio of orbitofrontal to amygdala volume is altered in schizophrenia

Raquel E. Gur; Christian G. Kohler; Bruce I. Turetsky; Steven J. Siegel; Stephen J. Kanes; Warren B. Bilker; Avis R. Brennan; Ruben C. Gur

Abstract Background Neuroanatomic sexual dimorphisms have been correlated with behavioral differences between healthy men and women. We have reported higher orbitofrontal cortex to amygdala ratio (OAR) in women than men. Although gender differences in schizophrenia are evident clinically and correlate with neuroanatomic measures, their relationship to OAR has not been examined. Methods Magnetic resonance imaging was performed in 31 neuroleptic-naive schizophrenic patients (16 men) and 80 healthy volunteers (34 men), aged less than 50 years. An automated tissue segmentation procedure was combined with expert-guided parcellation of orbitofrontal and amygdala volumes. Results Men with schizophrenia had increased OAR relative to healthy men, whereas women had decreased OAR. Increased OAR in men with schizophrenia reflected abnormally low amygdala volumes, whereas decreased OAR in women reflected abnormally low orbitofrontal volumes. Less severe negative symptoms were associated with increased OAR in men but with decreased OAR in women. In men, increased amygdala volume was associated with greater symptom severity, whereas in women higher volumes of both amygdala and orbitofrontal regions were associated with lesser severity of negative symptoms. Conclusions These opposite OAR abnormalities, whereby men show feminization and women masculinization, suggest gender-mediated effects of the underlying neuropathologic processes. The correlations with symptom severity suggest that neuroanatomic abnormalities in OAR reflect compensatory brain changes.


Journal of Neuroscience Methods | 2011

Automated Facial Action Coding System for Dynamic Analysis of Facial Expressions in Neuropsychiatric Disorders

Jihun Hamm; Christian G. Kohler; Ruben C. Gur; Ragini Verma

Facial expression is widely used to evaluate emotional impairment in neuropsychiatric disorders. Ekman and Friesens Facial Action Coding System (FACS) encodes movements of individual facial muscles from distinct momentary changes in facial appearance. Unlike facial expression ratings based on categorization of expressions into prototypical emotions (happiness, sadness, anger, fear, disgust, etc.), FACS can encode ambiguous and subtle expressions, and therefore is potentially more suitable for analyzing the small differences in facial affect. However, FACS rating requires extensive training, and is time consuming and subjective thus prone to bias. To overcome these limitations, we developed an automated FACS based on advanced computer science technology. The system automatically tracks faces in a video, extracts geometric and texture features, and produces temporal profiles of each facial muscle movement. These profiles are quantified to compute frequencies of single and combined Action Units (AUs) in videos, and they can facilitate a statistical study of large populations in disorders known to impact facial expression. We derived quantitative measures of flat and inappropriate facial affect automatically from temporal AU profiles. Applicability of the automated FACS was illustrated in a pilot study, by applying it to data of videos from eight schizophrenia patients and controls. We created temporal AU profiles that provided rich information on the dynamics of facial muscle movements for each subject. The quantitative measures of flatness and inappropriateness showed clear differences between patients and the controls, highlighting their potential in automatic and objective quantification of symptom severity.


Psychiatry Research-neuroimaging | 2009

Profile of auditory information-processing deficits in schizophrenia

Bruce I. Turetsky; Warren B. Bilker; Steven J. Siegel; Christian G. Kohler; Raquel E. Gur

Schizophrenia patients exhibit abnormalities in several different auditory event-related potential (ERP) measures. It is unclear how these abnormalities relate to each other, since multiple measures are rarely acquired from the same sample. This study addressed two related questions: 1) Are specific auditory ERP measures differentially impaired in schizophrenia? 2) Do abnormalities co-aggregate within the same patients? Nine auditory ERP measures were acquired in a single testing session from 23 schizophrenia patients and 22 healthy subjects. Hierarchical oblique factor analysis revealed that these measures aggregated into four factors, with each loading primarily on a single factor. Patient deficits were observed for two independent factors: N100/mismatch negativity (MMN) and P3a/P3b. N100/MMN abnormalities were associated with symptoms of alogia and formal thought disorder. P3a/P3b abnormalities were associated with avolition, attentional disturbances and delusions. We conclude that deficits in different ERP measures of early sensory processing at the level of the auditory cortex co-occur in patients. These likely represent a single differential deficit indexing the physiological abnormality underlying impaired language and verbal processing. This is relatively independent of a higher cortical deficit that mediates cognitive stimulus evaluation and underlies deficits in motivation, attention and reality testing. Such multidimensional profiling of ERP abnormalities may help to clarify the clinical and genetic heterogeneity of schizophrenia.


Schizophrenia Research | 2012

A meta-analysis of emotion perception and functional outcomes in schizophrenia

Farzin Irani; Sarah Seligman; Vidyulata Kamath; Christian G. Kohler; Ruben C. Gur

INTRODUCTION Emotion perception (EP) is impaired in schizophrenia, is stable across clinical state, resistant to antipsychotic treatment and linked to symptom severity. Given its pervasive nature, there is a need to quantitatively examine whether this dysfunction impacts functional outcomes. We used a meta-analytic strategy to combine results from several studies and examine synthesized effect sizes. METHODS A Meta-analysis of Observational Studies in Epidemiology standard was used to extract data following a PubMed and PsychInfo search. Studies reporting correlations between measures of EP and functional outcomes in schizophrenia spectrum disorders were selected. The impact of potential methodological (task type), demographic (sex, age, race, education, marital status) and clinical (age of onset, duration of illness, setting, symptoms, anti-psychotic medication) moderators on effect sizes were examined. RESULTS Twenty-five studies met inclusion criteria and included 1306 patients who were 37 years old, with 12 years of education, 64% male and 63% Caucasian. There was a significant relationship between EP and functional outcomes in individuals with schizophrenia or schizoaffective disorder, with effect sizes in the medium range. Medium to large range positive correlations were observed between emotion identification and functional outcome domains involving social problem solving, social skills and community functioning. Significant moderators included task type (emotion identification tasks), sex (% male in sample), race (% Caucasian in sample) and clinical symptoms (negative and positive). CONCLUSIONS Emotion identification deficits are associated with functional impairments in schizophrenia and moderated by sex, race and symptoms. This has implications for treatment efforts to improve outcomes.

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Raquel E. Gur

University of Pennsylvania

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Ruben C. Gur

University of Pennsylvania

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Warren B. Bilker

University of Pennsylvania

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Bruce I. Turetsky

University of Pennsylvania

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Monica E. Calkins

University of Pennsylvania

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Paul J. Moberg

University of Pennsylvania

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Steven J. Siegel

University of Pennsylvania

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James Loughead

University of Pennsylvania

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