Michael F Green

VA Greater Los Angeles Healthcare System, Los Ángeles, California, United States

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Publications (252)1503.76 Total impact

  • Naomi T Tabak · William P Horan · Michael F Green
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    ABSTRACT: Mindfulness-based interventions are gaining empirical support as alternative or adjunctive treatments for a variety of mental health conditions, including anxiety, depression, and substance use disorders. Emerging evidence now suggests that mindfulness-based treatments may also improve clinical features of schizophrenia, including negative symptoms. However, no research has examined the construct of mindfulness and its correlates in schizophrenia. In this study, we examined self-reported mindfulness in patients (n=35) and controls (n=25) using the Five-Facet Mindfulness Questionnaire. We examined correlations among mindfulness, negative symptoms, and psychological constructs associated with negative symptoms and adaptive functioning, including motivation, emotion regulation, and dysfunctional attitudes. As hypothesized, patients endorsed lower levels of mindfulness than controls. In patients, mindfulness was unrelated to negative symptoms, but it was associated with more adaptive emotion regulation (greater reappraisal) and beliefs (lower dysfunctional attitudes). Some facets of mindfulness were also associated with self-reported motivation (behavioral activation and inhibition). These patterns of correlations were similar in patients and controls. Findings from this initial study suggest that schizophrenia patients may benefit from mindfulness-based interventions because they (a) have lower self-reported mindfulness than controls and (b) demonstrate strong relationships between mindfulness and psychological constructs related to adaptive functioning. Copyright © 2015 Elsevier B.V. All rights reserved.
    Schizophrenia Research 07/2015; DOI:10.1016/j.schres.2015.07.030 · 4.43 Impact Factor
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    ABSTRACT: Effort-based decision making has strong conceptual links to the motivational disturbances that define a key subdomain of negative symptoms. However, the extent to which effort-based decision-making performance relates to negative symptoms, and other clinical and functionally important variables has yet to be systematically investigated. In 94 clinically stable outpatients with schizophrenia, we examined the external validity of 5 effort-based paradigms, including the Effort Expenditure for Rewards, Balloon Effort, Grip Strength Effort, Deck Choice Effort, and Perceptual Effort tasks. These tasks covered 3 types of effort: physical, cognitive, and perceptual. Correlations between effort related performance and 6 classes of variables were examined, including: (1) negative symptoms, (2) clinically rated motivation and community role functioning, (3) self-reported motivational traits, (4) neurocognition, (5) other psychiatric symptoms and clinical/demographic characteristics, and (6) subjective valuation of monetary rewards. Effort paradigms showed small to medium relationships to clinical ratings of negative symptoms, motivation, and functioning, with the pattern more consistent for some measures than others. They also showed small to medium relations with neurocognitive functioning, but were generally unrelated to other psychiatric symptoms, self-reported traits, antipsychotic medications, side effects, and subjective valuation of money. There were relatively strong interrelationships among the effort measures. In conjunction with findings from a companion psychometric article, all the paradigms warrant further consideration and development, and 2 show the strongest potential for clinical trial use at this juncture. © The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.
    Schizophrenia Bulletin 07/2015; DOI:10.1093/schbul/sbv090 · 8.61 Impact Factor
  • L Felice Reddy · William P Horan · Michael F Green
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    ABSTRACT: Recent years have seen a resurgence of interest in motivational disturbances in schizophrenia . This is largely driven by the recognition that these disturbances are central to the "experiential" subdomain of negative symptoms and are particularly important determinants of functional disability. Research into the causes and treatment of experiential negative symptoms is therefore a high priority. This chapter reviews findings from experimental psychopathology and affective science relevant to understanding the neurobehavioral processes that underlie these negative symptoms. We focus on abnormalities in four processes that have received the most attention as likely contributors: anticipatory pleasure, reward learning, effort-based decision-making, and social motivation. We also review the research literature on pharmacological and psychosocial approaches to reduce functional deficits attributable to negative symptoms. Translational research is beginning to inform the development of new treatments specifically designed to target the experiential subdomain of negative symptoms.
    07/2015; DOI:10.1007/7854_2015_379
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    ABSTRACT: Impairments in willingness to exert effort contribute to the motivational deficits characteristic of the negative symptoms of schizophrenia. The current study evaluated the psychometric properties of 5 new or adapted paradigms to determine their suitability for use in clinical trials of schizophrenia. This study included 94 clinically stable participants with schizophrenia and 40 healthy controls. The effort-based decision-making battery was administered twice to the schizophrenia group (baseline, 4-week retest) and once to the control group. The 5 paradigms included 1 that assesses cognitive effort, 1 perceptual effort, and 3 that assess physical effort. Each paradigm was evaluated on (1) patient vs healthy control group differences, (2) test-retest reliability, (3) utility as a repeated measure (ie, practice effects), and (4) tolerability. The 5 paradigms showed varying psychometric strengths and weaknesses. The Effort Expenditure for Rewards Task showed the best reliability and utility as a repeated measure, while the Grip Effort Task had significant patient-control group differences, and superior tolerability and administration duration. The other paradigms showed weaker psychometric characteristics in their current forms. These findings highlight challenges in adapting effort and motivation paradigms for use in clinical trials. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center 2015.
    Schizophrenia Bulletin 07/2015; DOI:10.1093/schbul/sbv089 · 8.61 Impact Factor
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    ABSTRACT: Schizophrenia is a severe and chronic medical condition, characterized by positive and negative symptoms, as well as pervasive social cognitive deficits. Despite the functional significance of the social cognition deficits affecting many aspects of daily living, such as social relationships, occupational status, and independent living, there is still no effective treatment option for these deficits, which is applied as standard of care. To address this need, we developed a novel, internet-based training program that targets social cognition deficits in schizophrenia (SocialVille). Preliminary studies demonstrate the feasibility and initial efficacy of Socialville in schizophrenia patients (Nahum et al., 2014). The purpose of the current trial (referred to as the TReatment of Social cognition in Schizophrenia Trial or TRuSST) is to compare SocialVille to an active control training condition, include a larger sample of patients, and assess both social cognitive functioning, and functional outcomes. We will employ a multi-site, longitudinal, blinded, randomized controlled trial (RCT) design with a target sample of 128 patients with schizophrenia. Patients will perform, at their home or in clinic, 40 sessions of either the SocialVille training program or an active control computer game condition. Each session will last for 40-45 minutes/day, performed 3-5 days a week, over 10-12 weeks, totaling to 30 hours of training. Patients will be assessed on a battery of social cognitive, social functioning and functional outcomes immediately before training, mid-way through training (after 20 training sessions) and at the completion of the 40 training sessions. The strengths of this protocol are that it tests an innovative, internet-based treatment that targets fundamental social cognitive deficits in schizophrenia, employs a highly sensitive and extensive battery of functional outcome measures, and incorporates a large sample size in an RCT design. ClinicalTrials.gov NCT02246426 Registered 16 September 2014.
    BMC Psychiatry 07/2015; 15(1):142. DOI:10.1186/s12888-015-0510-1 · 2.24 Impact Factor
  • Michael F Green · William P Horan
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    ABSTRACT: Effort-based decision making requires one to decide how much effort to expend for a certain amount of reward. As the amount of reward goes up most people are willing to exert more effort. This relationship between reward level and effort expenditure can be measured in specialized performance-based tasks that have only recently been applied to schizophrenia. Such tasks provide a way to measure objectively motivational deficits in schizophrenia, which now are only assessed with clinical interviews of negative symptoms. The articles in this theme provide reviews of the relevant animal and human literatures (first 2 articles), and then a psychometric evaluation of 5 effort-based decision making paradigms (last 2 articles). This theme section is intended to stimulate interest in this emerging area among basic scientists developing paradigms for preclinical studies, human experimentalists trying to disentangle factors that contribute to performance on effort-based tasks, and investigators looking for objective endpoints for clinical trials of negative symptoms in schizophrenia. © The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.
    Schizophrenia Bulletin 06/2015; 41(5). DOI:10.1093/schbul/sbv084 · 8.61 Impact Factor
  • Michael F Green · William P Horan · Deanna M Barch · James M Gold
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    ABSTRACT: Because negative symptoms, including motivational deficits, are a critical unmet need in schizophrenia, there are many ongoing efforts to develop new pharmacological and psychosocial interventions for these impairments. A common challenge of these studies involves how to evaluate and select optimal endpoints. Currently, all studies of negative symptoms in schizophrenia depend on ratings from clinician-conducted interviews. Effort-based decision-making tasks may provide a more objective, and perhaps more sensitive, endpoint for trials of motivational negative symptoms. These tasks assess how much effort a person is willing to exert for a given level of reward. This area has been well-studied with animal models of effort and motivation, and effort-based decision-making tasks have been adapted for use in humans. Very recently, several studies have examined physical and cognitive types of effort-based decision-making tasks in cross-sectional studies of schizophrenia, providing evidence for effort-related impairment in this illness. This article covers the theoretical background on effort-based decision-making tasks to provide a context for the subsequent articles in this theme section. In addition, we review the existing literature of studies using these tasks in schizophrenia, consider some practical challenges in adapting them for use in clinical trials in schizophrenia, and discuss interpretive challenges that are central to these types of tasks. © The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.
    Schizophrenia Bulletin 06/2015; DOI:10.1093/schbul/sbv071 · 8.61 Impact Factor
  • Amy E Pinkham · David L Penn · Michael F Green · Philip D Harvey
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    ABSTRACT: Measurement of social cognition in treatment trials remains problematic due to poor and limited psychometric data for many tasks. As part of the Social Cognition Psychometric Evaluation (SCOPE) study, the psychometric properties of 8 tasks were assessed. One hundred and seventy-nine stable outpatients with schizophrenia and 104 healthy controls completed the battery at baseline and a 2-4-week retest period at 2 sites. Tasks included the Ambiguous Intentions Hostility Questionnaire (AIHQ), Bell Lysaker Emotion Recognition Task (BLERT), Penn Emotion Recognition Task (ER-40), Relationships Across Domains (RAD), Reading the Mind in the Eyes Task (Eyes), The Awareness of Social Inferences Test (TASIT), Hinting Task, and Trustworthiness Task. Tasks were evaluated on: (i) test-retest reliability, (ii) utility as a repeated measure, (iii) relationship to functional outcome, (iv) practicality and tolerability, (v) sensitivity to group differences, and (vi) internal consistency. The BLERT and Hinting task showed the strongest psychometric properties across all evaluation criteria and are recommended for use in clinical trials. The ER-40, Eyes Task, and TASIT showed somewhat weaker psychometric properties and require further study. The AIHQ, RAD, and Trustworthiness Task showed poorer psychometric properties that suggest caution for their use in clinical trials. © The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.
    Schizophrenia Bulletin 05/2015; DOI:10.1093/schbul/sbv056 · 8.61 Impact Factor
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    ABSTRACT: Research on empathy in schizophrenia has relied on dated self-report scales that do not conform to contemporary social neuroscience models of empathy. The current study evaluated the structure and correlates of the recently-developed Questionnaire of Cognitive and Affective Empathy (QCAE) in schizophrenia. This measure, whose structure and validity was established in healthy individuals, includes separate scales to assess the two main components of empathy: Cognitive Empathy (assessed by two subscales) and Affective Empathy (assessed by three subscales). Stable outpatients with schizophrenia (n = 145) and healthy individuals (n = 45) completed the QCAE, alternative measures of empathy, and assessments of clinical symptoms, neurocognition, and functional outcome. Exploratory and confirmatory factor analyses provided consistent support for a two-factor solution in the schizophrenia group, justifying the use of separate cognitive and affective empathy scales in this population. However, one of the three Affective Empathy subscales was not psychometrically sound and was excluded from further analyses. Patients reported significantly lower Cognitive Empathy but higher Affective Empathy than controls. Among patients, the QCAE scales showed significant correlations with an alternative self-report empathy scale, but not with performance on an empathic accuracy task. The QCAE Cognitive Empathy subscales also showed significant, though modest, correlations with negative symptoms and functional outcome. These findings indicate that structure of self-reported empathy is similar in people with schizophrenia and healthy subjects, and can be meaningfully compared between groups. They also contribute to emerging evidence that some aspects of empathy may be intact or hyper-responsive in schizophrenia. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Journal of Psychiatric Research 04/2015; 66-67. DOI:10.1016/j.jpsychires.2015.04.016 · 4.09 Impact Factor
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    ABSTRACT: In this preliminary study, we examined the effect of transcranial direct current stimulation (tDCS) on social cognition in 36 individuals with schizophrenia. Participants received a baseline assessment and one week later received either anodal, cathodal, or sham tDCS, with 12 participants randomized to each condition. A single 20-minute session tDCS was administered bilaterally over the dorsolateral prefrontal cortex (centered at positions Fp1 and Fp2) at 2mA. Among the 4 social cognitive tasks, participants showed a significant improvement on one of them, emotion identification, following anodal stimulation. Findings demonstrate the safety of this procedure and suggest potential therapeutic effects on one aspect of social cognition in schizophrenia. Copyright © 2015 Elsevier B.V. All rights reserved.
    Schizophrenia Research 04/2015; 165(2-3). DOI:10.1016/j.schres.2015.04.016 · 4.43 Impact Factor
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    ABSTRACT: Schizophrenia patients exhibit well-documented visual processing deficits. One area of disruption is visual integration, the ability to form global objects from local elements. However, most studies of visual integration in schizophrenia have been conducted in the context of an active attention task, which may influence the findings. In this study we examined visual integration using electroencephalography (EEG) in a passive task to elucidate neural mechanisms associated with poor visual integration. Forty-six schizophrenia patients and 30 healthy controls had EEG recorded while passively viewing figures comprised of real, illusory, or no contours. We examined visual P100, N100, and P200 event-related potential (ERP) components, as well as neural synchronization in the gamma (30-60 Hz) band assessed by the EEG phase locking factor (PLF). The N100 was significantly larger to illusory vs. no contour, and illusory vs. real contour stimuli while the P200 was larger only to real vs. illusory stimuli; there were no significant interactions with group. Compared to controls, patients failed to show increased phase locking to illusory versus no contours between 40-60 Hz. Also, controls, but not patients, had larger PLF between 30-40 Hz when viewing real vs. illusory contours. Finally, the positive symptom factor of the BPRS was negatively correlated with PLF values between 40-60 Hz to illusory stimuli, and with PLF between 30-40 Hz to real contour stimuli. These results suggest that the pattern of results across visual processing conditions is similar in patients and controls. However, patients have deficits in neural synchronization in the gamma range during basic processing of illusory contours when attentional demand is limited.
    PLoS ONE 03/2015; 10(3):e0119849. DOI:10.1371/journal.pone.0119849 · 3.23 Impact Factor
  • Michael F Green · Katiah Llerena · Robert S Kern
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    ABSTRACT: It has been about 15 years since we published our article asking whether we are measuring the "Right Stuff" as we search for predictors and determinants of functional outcome in schizophrenia. At that time, we raised the question as to whether the neurocognitive assessments used to study outcome in schizophrenia were too narrow to capture the wide variability in factors that determine daily functioning. While the study of the determinants of functioning in schizophrenia has grown and matured, we are struck by 3 aspects of the article that evolved in different directions. First, the selection of outcome domains in the Right Stuff meta-analysis reflects a focus at that time on predictors of psychiatric rehabilitation. Second, expansion beyond traditional neurocognitive domains occurred in one suggested area (social cognition), but not another (learning potential). Third, the field has responded assertively to the recommendation to evaluate more informed and informative theoretical models. © The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.
    Schizophrenia Bulletin 03/2015; 41(4). DOI:10.1093/schbul/sbv018 · 8.61 Impact Factor
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    ABSTRACT: Attention/vigilance impairments are present in individuals with schizophrenia across psychotic and remitted states and in their first-degree relatives. An important question is whether deficits in attention/vigilance can be consistently and reliably measured across sites varying in many participant demographic, clinical, and functional characteristics, as needed for large-scale genetic studies of endophenotypes. We examined Continuous Performance Test (CPT) data from phase 2 of the Consortium on the Genetics of Schizophrenia (COGS-2), the largest-scale assessment of cognitive and psychophysiological endophenotypes relevant to schizophrenia. The CPT data from 2251 participants from five sites were examined. A perceptual-load vigilance task (the Degraded Stimulus CPT or DS-CPT) and a memory-load vigilance task (CPT-Identical Pairs or CPT-IP) were utilized. Schizophrenia patients performed more poorly than healthy comparison subjects (HCS) across sites, despite significant site differences in participant age, sex, education, and racial distribution. Patient-HCS differences in signal/noise discrimination (d') in the DS-CPT varied significantly across sites, but averaged a medium effect size. CPT-IP performance showed large patient-HCS differences across sites. Poor CPT performance was independent of or weakly correlated with symptom severity, but was significantly associated with lower educational achievement and functional capacity. Current smoking was associated with poorer CPT-IP d'. Patients taking both atypical and typical antipsychotic medication performed more poorly than those on no or atypical antipsychotic medications, likely reflecting their greater severity of illness. We conclude that CPT deficits in schizophrenia can be reliably detected across sites, are relatively independent of current symptom severity, and are related to functional capacity. Copyright © 2015 Elsevier B.V. All rights reserved.
    Schizophrenia Research 03/2015; 163(1-3). DOI:10.1016/j.schres.2015.01.017 · 4.43 Impact Factor
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    ABSTRACT: This Phase II exploratory study assessed GSK239512, a brain penetrant histamine H3 receptor antagonist, versus placebo on cognitive impairment in 50 stable outpatients with schizophrenia. Subjects were randomized to placebo or GSK239512 for 7weeks (4weeks titration). GSK239512 was associated with a small positive effect size (ES) on the CogState Schizophrenia Battery (CSSB) Composite Score (ES=0.29, CI=-0.40, 0.99) relative to placebo (primary endpoint). GSK239512's ES on CSSB domains were generally positive or neutral except Processing Speed, which favored placebo (ES=-0.46). Effects on the MATRICS Consensus Cognitive Battery were mostly neutral or favored placebo. GSK239512 was generally well tolerated with an adverse event profile consistent with the known class pharmacology. There was no evidence of overall beneficial effects of GSK239512 for CIAS in this population. Copyright © 2015 Elsevier B.V. All rights reserved.
    Schizophrenia Research 02/2015; 164(1-3). DOI:10.1016/j.schres.2015.01.041 · 4.43 Impact Factor
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    ABSTRACT: Although many endophenotypes for schizophrenia have been studied individually, few studies have examined the extent to which common neurocognitive and neurophysiological measures reflect shared versus unique endophenotypic factors. It may be possible to distill individual endophenotypes into composite measures that reflect dissociable, genetically informative elements. The first phase of the Consortium on the Genetics of Schizophrenia (COGS-1) is a multisite family study that collected neurocognitive and neurophysiological data between 2003 and 2008. For these analyses, participants included schizophrenia probands (n=83), their nonpsychotic siblings (n=151), and community comparison subjects (n=209) with complete data on a battery of 12 neurocognitive tests (assessing domains of working memory, declarative memory, vigilance, spatial ability, abstract reasoning, facial emotion processing, and motor speed) and 3 neurophysiological tasks reflecting inhibitory processing (P50 gating, prepulse inhibition and antisaccade tasks). Factor analyses were conducted on the measures for each subject group and across the entire sample. Heritability analyses of factors were performed using SOLAR. Analyses yielded 5 distinct factors: 1) Episodic Memory, 2) Working Memory, 3) Perceptual Vigilance, 4) Visual Abstraction, and 5) Inhibitory Processing. Neurophysiological measures had low associations with these factors. The factor structure of endophenotypes was largely comparable across probands, siblings and controls. Significant heritability estimates for the factors ranged from 22% (Episodic Memory) to 39% (Visual Abstraction). Neurocognitive measures reflect a meaningful amount of shared variance whereas the neurophysiological measures reflect largely unique contributions as endophenotypes for schizophrenia. Composite endophenotype measures may inform our neurobiological and genetic understanding of schizophrenia. Copyright © 2015. Published by Elsevier B.V.
    Schizophrenia Research 02/2015; 163(1-3). DOI:10.1016/j.schres.2015.01.027 · 4.43 Impact Factor
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    ABSTRACT: Schizophrenia and bipolar disorder have been associated with shared and distinct emotion processing abnormalities. Initial findings indicate that these disorders differ with respect to the domain of emotional intelligence (EI). Individuals with schizophrenia display deficits on performance measures of EI, whereas those with bipolar disorder do not. However, no research has examined patients' subjective beliefs about their own EI (referred to as “perceived EI”). This study examined perceived EI, assessed with the Trait Meta-Mood Scale (TMMS), and its clinical and functional correlates in outpatients with schizophrenia (n = 35) or bipolar disorder I (n = 38) and matched healthy controls (n = 35). The TMMS includes three subscales that assess beliefs about one's ability to attend to (Attention to Feelings), understand (Clarity of Feelings), and repair emotions (Mood Repair). Participants in the clinical groups also completed community functioning and symptom assessments. Both clinical groups reported significantly lower perceived EI than controls, but did not differ from each other. Higher total TMMS correlated with higher levels of independent living in the schizophrenia group (r = .36) and better social functioning in the bipolar group (r = .61). In addition, although higher Attention to Feelings scores correlated with greater psychiatric symptoms in the schizophrenia group, higher scores across all subscales correlated with less manic symptoms in the bipolar group. The findings suggest that perceived EI is impaired and related to community functioning in both disorders.
    Schizophrenia Research 01/2015; 162(1-3). DOI:10.1016/j.schres.2014.12.005 · 4.43 Impact Factor
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    ABSTRACT: The impaired ability to make correct antisaccades (i.e., antisaccade performance) is well documented among schizophrenia subjects, and researchers have successfully demonstrated that antisaccade performance is a valid schizophrenia endophenotype that is useful for genetic studies. However, it is unclear how the ascertainment biases that unavoidably result from recruitment differences in schizophrenia subjects identified in family versus case-control studies may influence patient-control differences in antisaccade performance. To assess the impact of ascertainment bias, researchers from the Consortium on the Genetics of Schizophrenia (COGS) compared antisaccade performance and antisaccade metrics (latency and gain) in schizophrenia and control subjects from COGS-1, a family-based schizophrenia study, to schizophrenia and control subjects from COGS-2, a corresponding case-control study. COGS-2 schizophrenia subjects were substantially older; had lower education status, worse psychosocial function, and more severe symptoms; and were three times more likely to be a member of a multiplex family than COGS-1 schizophrenia subjects. Despite these variations, which were likely the result of ascertainment differences (as described in the introduction to this special issue), the effect sizes of the control-schizophrenia differences in antisaccade performance were similar in both studies (Cohen's d effect size of 1.06 and 1.01 in COGS-1 and COGS-2, respectively). This suggests that, in addition to the robust, state-independent schizophrenia-related deficits described in endophenotype studies, group differences in antisaccade performance do not vary based on subject ascertainment and recruitment factors. Published by Elsevier B.V.
    Schizophrenia Research 12/2014; 163(1-3). DOI:10.1016/j.schres.2014.12.016 · 4.43 Impact Factor
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    ABSTRACT: The first phase of the Consortium on the Genetics of Schizophrenia (COGS-1) showed performance deficits in learning and memory on the California Verbal Learning Test, Second Edition (CVLT-II) in individuals with schizophrenia (SZ), compared to healthy comparison subjects (HCS). A question is whether the COGS-1 study, which used a family study design (i.e. studying relatively intact families), yielded "milder" SZ phenotypes than those acquired subsequently in the COGS-2 case-control design that did not recruit unaffected family members. CVLT-II performance was compared for the COGS-1 and COGS-2 samples. Analyses focused on learning, recall and recognition variables, with age, gender and education as covariates. Analyses of COGS-2 data explored effects of additional covariates and moderating factors in CVLT-II performance. 324 SZ subjects and 510 HCS had complete CVLT-II and covariate data in COGS-1, while 1356 SZ and 1036 HCS had complete data in COGS-2. Except for recognition memory, analysis of covariance showed significantly worse performance in COGS-2 on all CVLT-II variables for SZ and HCS, and remained significant in the presence of the covariates. Performance in each of the 5 learning trials differed significantly. However, effect sizes comparing cases and controls were comparable across the two studies. COGS-2 analyses confirmed SZ performance deficits despite effects of multiple significant covariates and moderating factors. CVLT-II performance was worse in COGS-2 than in COGS-1 for both the SZ and the HCS in this large cohort, likely due to cohort effects. Demographically corrected data yield a consistent pattern of performance across the two studies in SZ. Copyright © 2014. Published by Elsevier B.V.
    Schizophrenia Research 12/2014; 163(1-3). DOI:10.1016/j.schres.2014.10.029 · 4.43 Impact Factor
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    ABSTRACT: IntroductionThe ability to recognize human biological motion is a fundamental aspect of social cognition that is impaired in people with schizophrenia. However, little is known about the neural substrates of impaired biological motion perception in schizophrenia. In the current study, we assessed event-related potentials (ERPs) to human and nonhuman movement in schizophrenia.Methods Twenty-four subjects with schizophrenia and 18 healthy controls completed a biological motion task while their electroencephalography (EEG) was simultaneously recorded. Subjects watched clips of point-light animations containing 100%, 85%, or 70% biological motion, and were asked to decide whether the clip resembled human or nonhuman movement. Three ERPs were examined: P1, N1, and the late positive potential (LPP).ResultsBehaviorally, schizophrenia subjects identified significantly fewer stimuli as human movement compared to healthy controls in the 100% and 85% conditions. At the neural level, P1 was reduced in the schizophrenia group but did not differ among conditions in either group. There were no group differences in N1 but both groups had the largest N1 in the 70% condition. There was a condition × group interaction for the LPP: Healthy controls had a larger LPP to 100% versus 85% and 70% biological motion; there was no difference among conditions in schizophrenia subjects.Conclusions Consistent with previous findings, schizophrenia subjects were impaired in their ability to recognize biological motion. The EEG results showed that biological motion did not influence the earliest stage of visual processing (P1). Although schizophrenia subjects showed the same pattern of N1 results relative to healthy controls, they were impaired at a later stage (LPP), reflecting a dysfunction in the identification of human form in biological versus nonbiological motion stimuli.
    Brain and Behavior 12/2014; 5(1). DOI:10.1002/brb3.303
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    ABSTRACT: Neurocognitive deficits in schizophrenia (SZ) are established and the Consortium on the Genetics of Schizophrenia (COGS) investigated such measures as endophenotypes in family-based (COGS-1) and case-control (COGS-2) studies. By requiring family participation, family-based sampling may result in samples that vary demographically and perform better on neurocognitive measures. The Penn computerized neurocognitive battery (CNB) evaluates accuracy and speed of performance for several domains and was administered across sites in COGS-1 and COGS-2. Most tests were included in both studies. COGS-1 included 328 patients with SZ and 497 healthy comparison subjects (HCS) and COGS-2 included 1195 patients and 1009 HCS. Demographically, COGS-1 participants were younger, more educated, with more educated parents and higher estimated IQ compared to COGS-2 participants. After controlling for demographics, the two samples produced very similar performance profiles compared to their respective controls. As expected, performance was better and with smaller effect sizes compared to controls in COGS-1 relative to COGS-2. Better performance was most pronounced for spatial processing while emotion identification had large effect sizes for both accuracy and speed in both samples. Performance was positively correlated with functioning and negatively with negative and positive symptoms in both samples, but correlations were attenuated in COGS-2, especially with positive symptoms. Patients ascertained through family-based design have more favorable demographics and better performance on some neurocognitive domains. Thus, studies that use case-control ascertainment may tap into populations with more severe forms of illness that are exposed to less favorable factors compared to those ascertained with family-based designs. Published by Elsevier B.V.
    Schizophrenia Research 11/2014; 163(1-3). DOI:10.1016/j.schres.2014.10.049 · 4.43 Impact Factor

Publication Stats

13k Citations
1,503.76 Total Impact Points

Institutions

  • 2005–2015
    • VA Greater Los Angeles Healthcare System
      Los Ángeles, California, United States
    • University of Houston
      • Department of Psychology
      Houston, Texas, United States
  • 1994–2015
    • University of California, Los Angeles
      • • Department of Psychiatry and Biobehavioural Sciences
      • • Institute for Neuroscience and Human Behavior
      • • Division of Adult Psychiatry
      Los Ángeles, California, United States
  • 2014
    • The Psychonomic Society
      Society Hill, New Jersey, United States
  • 2013
    • United States Department of Veterans Affairs
      Бедфорд, Massachusetts, United States
    • Southern Methodist University
      • Department of Psychology
      Dallas, TX, United States
    • Cairo University
      • Department of Psychiatry
      Al Qāhirah, Muḩāfaz̧at al Qāhirah, Egypt
    • Fordham University
      • Department of Psychology
      United States
  • 2011–2013
    • Harvard University
      Cambridge, Massachusetts, United States
    • Heinrich-Heine-Universität Düsseldorf
      Düsseldorf, North Rhine-Westphalia, Germany
  • 2012
    • Douglas Mental Health University Institute
      Montréal, Quebec, Canada
  • 2009
    • Oslo University Hospital
      Kristiania (historical), Oslo County, Norway
  • 2008
    • Duke University
      Durham, North Carolina, United States
  • 2007–2008
    • Pacific Neuropsychiatric Institute
      Seattle, Washington, United States
    • Los Angeles Neurosurgical Institute
      Los Ángeles, California, United States
  • 2005–2007
    • California State University, Northridge
      • Department of Psychology
      Los Angeles, CA, United States
  • 2006
    • University of California, San Diego
      • Department of Psychiatry
      San Diego, California, United States
  • 1994–2006
    • CSU Mentor
      Long Beach, California, United States
  • 2004
    • Universität Osnabrück
      Osnabrück, Lower Saxony, Germany
  • 2002
    • University of Southern California
      • Department of Psychology
      Los Angeles, California, United States
  • 1999
    • University of Bergen
      • Department of Biological and Medical Psychology
      Bergen, Hordaland Fylke, Norway
  • 1998
    • MFG Chemical
      Georgia, United States
  • 1992
    • University of Arkansas at Little Rock
      Little Rock, Arkansas, United States