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When investigating metacommunity dynamics, functional differences among species are often assumed to be as important as environmental differences between sites in determining beta-diversity. However, few studies have examined the influence of functional diversity on beta-diversity. We examine the relative importance of regional functional diversity partitioned by niche dimensions and environmental variation in structuring taxonomic beta-diversity of stream fishes using a large dataset of stream fish assemblages (hereafter, simply beta-diversity). We predicted that both functional diversity and environmental variation play a role in determining beta-diversity. We tested this prediction by modelling the patterns of stream fish beta-diversity as a function of environmental variation, functional diversity and gamma-richness across 10,220 sites for 329 fish species using a series of conceptual path models. Environmental variation consistently affected beta-diversity across all models, whereas functional diversity and gamma-richness influenced beta-diversity only in some models. We show that including relevant trait differences among species in path models can improve their ability to explain beta-diversity, suggesting that functional traits influence beta-diversity. The ability of path models to explain beta-diversity varied depending on the trait grouping included in the model, demonstrating that specific path models representing different niche dimensions can improve the ability of a model to explain beta-diversity. In addition, parsing traits into different niche dimensions revealed alternative patterns of functional diversity-beta-diversity relationships that otherwise would have been missed. The selection of relevant traits and linked niche dimensions is critical for detecting relationships between functional diversity and beta-diversity. Using traits associated with different niche dimensions allows for the identification of niche dimensions most strongly associated with species sorting and the detection of patterns missed by focusing on a single niche dimension. Determining the niche dimensions that influence beta-diversity could provide insights into the processes driving biodiversity and metacommunity dynamics, improving our ability to conserve or restore aquatic communities. USDA/NIFA [SC-1700599]; National Science Foundation [DEB-2017795] Published version First and foremost, we thank the numerous agency and university employees who contributed to the dataset. We thank T. Wagner and S. Midway for facilitating access to the fish dataset, and E. Frimpong for access to the FishTraits dataset. This work was supported in part by the USDA/NIFA, under project no. SC-1700599, and represents technical contribution no. 6994 of the Clemson Experiment Station. This material is based upon work supported by the National Science Foundation under project DEB-2017795. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

The validity of self-report psychopathy assessment has been questioned, especially in forensic settings where clinical evaluations influence critical decision-making (e.g., institutional placement, parole eligibility). Informant-based assessment offers a potentially valuable supplement to self-report but is challenging to acquire in under-resourced forensic contexts. The current study evaluated, within an incarcerated sample (n = 322), the extent to which brief prototype-based informant ratings of psychopathic traits as described by the triarchic model (boldness, meanness, disinhibition; Patrick et al., 2009) converge with self-report trait scores and show incremental validity in predicting criterion measures. Self/informant convergence was robust for traits of boldness and disinhibition, but weaker for meanness. Informant-rated traits showed incremental predictive validity over self-report traits, both within and across assessment domains. These findings indicate that simple prototype-based informant ratings of the triarchic traits can provide a useful supplement to self-report in assessing psychopathy within forensic-clinical settings.

The Hierarchical Taxonomy of Psychopathology (HiTOP) represents a crucial step forward in the empirical refinement of psychiatric nosology. Although grounded in factor analyses of clinical symptoms and affiliated traits, HiTOP encourages research using measures of other types, including neural-system variables, to clarify coherent processes contributing to the hierarchical structure of psychopathology. However, systematic strategies for interfacing HiTOP dimensions with neural-system variables have not been put forth. We discuss reasons for considering neurobiological systems in relation to HiTOP (i.e. 'why') and propose alternative strategies that might be used to develop an interface between HiTOP and neurobiology (i.e. 'how'). In particular, we highlight potential advantages and limitations of establishing this interface through reference to (i) HiTOP dimensions themselves, or conventional personality trait models linked to HiTOP; (ii) alternative trait constructs designed to link conventional personality models and neurobiological measures; and (iii) mechanistic models of neurobiological processes relevant to HiTOP constructs, derived from computational modelling. We discuss the importance of establishing an interface between HiTOP and neurobiology to develop a more comprehensive, mechanistic understanding of psychopathology and to guide the refinement of the HiTOP model. Such efforts have the potential to guide the development and provision of effective, individualized psychological treatment.

This study examined associations of performance-monitoring event-related potentials (ERPs) from go/no-go and flanker tasks with one another, and with psychopathy-related traits of disinhibition, meanness, and boldness. A task-dependent relationship was evident between the error-related negativity (ERN) and trait disinhibition, with high-disinhibited participants showing reduced no-go ERN but not flanker ERN. Disinhibition was also inversely related to variants of the P3 and the error positivity (Pe) from these two tasks. A factor analysis of the ERPs revealed two distinct factors, one reflecting shared variance among the P3 and Pe measures from the two tasks, and the other covariance among the N2 and ERN measures. Scores on the P3/Pe factor, but not the N2/ERN factor, were inversely related to disinhibition, and accounted for associations of this trait with variants of the P3 and Pe across tasks. The implication is that high trait disinhibition relates mainly to reductions in brain responses associated with later elaborative stages in the processing of motivationally significant events across different tasks. Importantly, no-go ERN predicted disinhibition scores beyond N2/ERN factor scores, indicating that high disinhibition is not generally related to diminished early preresponse conflict and error processing, but rather to processing impairments in conditions calling for inhibition of prepotent response tendencies.

Accurately characterizing spatial patterns on landscapes is necessary to understand the processes that generate biodiversity, a problem that has applications in ecological theory, conservation planning, ecosystem restoration, and ecosystem management. However, the measurement of biodiversity patterns and the ecological and evolutionary processes that underlie those patterns is highly dependent on the study unit size, boundary placement, and number of observations. These issues, together known as the modifiable areal unit problem, are well known in geography. These factors limit the degree to which results from different metacommunity and macro-ecological studies can be compared to draw new inferences, and yet these types of comparisons are widespread in community ecology. Using aquatic community datasets, we demonstrate that spatial context drives analytical results when landscapes are sub-divided. Next, we present a framework for using resampling and neighborhood smoothing to standardize datasets to allow for inferential comparisons. We then provide examples for how addressing these issues enhances our ability to understand the processes shaping ecological communities at landscape scales and allows for informative meta-analytical synthesis. We conclude by calling for greater recognition of issues derived from the modifiable areal unit problem in community ecology, discuss implications of the problem for interpreting the existing literature, and identify tools and approaches for future research.

Shortcomings of approaches to classifying psychopathology based on expert consensus have given rise to contemporary efforts to classify psychopathology quantitatively. In this paper, we review progress in achieving a quantitative and empirical classification of psychopathology. A substantial empirical literature indicates that psychopathology is generally more dimensional than categorical. When the discreteness versus continuity of psychopathology is treated as a research question, as opposed to being decided as a matter of tradition, the evidence clearly supports the hypothesis of continuity. In addition, a related body of literature shows how psychopathology dimensions can be arranged in a hierarchy, ranging from very broad "spectrum level'' dimensions, to specific and narrow clusters of symptoms. In this way, a quantitative approach solves the "problem of comorbidity'' by explicitly modeling patterns of co-occurrence among signs and symptoms within a detailed and variegated hierarchy of dimensional concepts with direct clinical utility. Indeed, extensive evidence pertaining to the dimensional and hierarchical structure of psychopathology has led to the formation of the Hierarchical Taxonomy of Psychopathology (HiTOP) Consortium. This is a group of 70 investigators working together to study empirical classification of psychopathology. In this paper, we describe the aims and current foci of the HiTOP Consortium. These aims pertain to continued research on the empirical organization of psychopathology; the connection between personality and psychopathology; the utility of empirically based psychopathology constructs in both research and the clinic; and the development of novel and comprehensive models and corresponding assessment instruments for psychopathology constructs derived from an empirical approach. (C) 2020 Published by Elsevier Masson SAS.

Author(s): Hopwood, Christopher J; Kotov, Roman; Krueger, Robert F; Watson, David; Widiger, Thomas A; Althoff, Robert R; Ansell, Emily B; Bach, Bo; Michael Bagby, R; Blais, Mark A; Bornovalova, Marina A; Chmielewski, Michael; Cicero, David C; Conway, Christopher; De Clercq, Barbara; De Fruyt, Filip; Docherty, Anna R; Eaton, Nicholas R; Edens, John F; Forbes, Miriam K; Forbush, Kelsie T; Hengartner, Michael P; Ivanova, Masha Y; Leising, Daniel; John Livesley, W; Lukowitsky, Mark R; Lynam, Donald R; Markon, Kristian E; Miller, Joshua D; Morey, Leslie C; Mullins-Sweatt, Stephanie N; Hans Ormel, J; Patrick, Christopher J; Pincus, Aaron L; Ruggero, Camilo; Samuel, Douglas B; Sellbom, Martin; Slade, Tim; Tackett, Jennifer L; Thomas, Katherine M; Trull, Timothy J; Vachon, David D; Waldman, Irwin D; Waszczuk, Monika A; Waugh, Mark H; Wright, Aidan GC; Yalch, Mathew M; Zald, David H; Zimmermann, Johannes

The etiology of major depressive disorder is heterogeneous, and differing pathways leading to the development of depression are proposed to account for alternative variants of depressive illness and their distinct comorbidity patterns. The present study was undertaken as a step toward developing a model for conceptualizing and quantifying dispositional proneness to depression, marked by reduced neural sensitivity to rewarding events and more persistent occurrence of depressive symptomatology. Using data for college and community adult participants (N = 201), we sought to quantify variations in depression proneness by combining symptom indicators of persistent depressive conditions (dysthymic disorder, depressive personality) with a brain potential response that has been shown to index sensitivity to pleasurable events-the reward positivity (RewP; Proudfit, 2015). We first extended prior work on the RewP and depression by showing that the magnitude of RewP covaried negatively with symptoms of persistent depressive conditions (dysthymia, depressive personality) but not with current levels of depression. Persistent depressive symptoms and the RewP were then combined to form a composite neuroclinical index of depression proneness. Compared to persistent depressive symptoms alone, this composite dimensional index showed improved specificity of relations with diagnostic criterion measures, that is, similar-level associations with other indicators of depression proneness but significantly lower associations with fear disorder symptomatology. These findings provide evidence that a dimension of depression proneness can be quantified effectively by combining psychological indicators of persistent depression with a neurophysiological index of a core depression-related process (i.e., reward sensitivity).

The National Institute of Mental Health's (NIMH) Research Domain Criteria (RDoC) initiative seeks to establish new dimensional conceptions of mental health problems, through the investigation of clinically relevant "process" constructs that have neurobiological as well as psychological referents. This special issue provides a detailed overview of the RDoC framework by NIMH officials Michael Kozak and Bruce Cuthbert, and spotlights RDoC-oriented investigative efforts by leading psychophysiological research groups as examples of how clinical science might be reshaped through application of RDoC principles. Accompanying commentaries highlight key aspects of the work by each group, and discuss reported methods/findings in relation to promises and challenges of the RDoC initiative more broadly.

The National Institute of Mental Health's Research Domain Criteria (RDoC) initiative calls for the incorporation of neurobiological approaches and findings into conceptions of mental health problems through a focus on biobehavioral constructs investigated across multiple domains of measurement (units of analysis). Although the constructs in the RDoC system are characterized in "process terms" (i.e., as functional concepts with brain and behavioral referents), these constructs can also be framed as dispositions (i.e., as dimensions of variation in biobehavioral functioning across individuals). Focusing on one key RDoC construct, acute threat or "fear," the current article illustrates a construct-oriented psychoneurometric strategy for operationalizing this construct in individual difference terms-as threat sensitivity (THT+). Utilizing data from 454 adult participants, we demonstrate empirically that (a) a scale measure of THT+ designed to tap general fear/fearlessness predicts effectively to relevant clinical problems (i.e., fear disorder symptoms), (b) this scale measure shows reliable associations with physiological indices of acute reactivity to aversive visual stimuli, and (c) a cross-domain factor reflecting the intersection of scale and physiological indicators of THT+ predicts effectively to both clinical and neurophysiological criterion measures. Results illustrate how the psychoneurometric approach can be used to create a dimensional index of a biobehavioral trait construct, in this case THT+, which can serve as a bridge between phenomena in domains of psychopathology and neurobiology. Implications and future directions are discussed with reference to the RDoC initiative and existing report-based conceptions of psychological traits.

As highlighted by articles in the current special issue, the RDoC initiative holds promise for advancing understanding of mental health problems. However, the initiative is at its early stages and it remains unclear what level of progress can be achieved and how quickly. In this closing article, we identify major challenges facing RDoC and propose concrete approaches to addressing these challenges, including (a) clearer specification of clinical problems for study, with use of symptom dimensions from integrative dimensional models of psychopathology as provisional, modifiable referents; (b) encouragement of research on a distinct set of traits corresponding to process constructs from the RDoC matrix-those represented across animal, child temperament, and adult personality literatures-to serve as interfaces between matrix constructs and clinical problems; (c) an emphasis in the near term on use of proximal units of analysis in RDoC studies-in particular, on physiological, behavioral, and self-report measures of matrix constructs (examined as states or traits, or both); (d) inclusion of a clear ontogenetic-developmental component in RDoC research projects; (e) routine analysis of the psychometric properties of nonreport (e.g., physiological, task-behavioral) variables, including systematic evaluation of their reliability and convergent-discriminant validity; (f) modification of existing grant review criteria to prioritize replication and synergy in RDoC investigative work; and (g) creation of a cumulative data network system (RDoC-DataWeb) to encourage and facilitate coordination of research efforts across RDoC research groups.

The triarchic model (Patrick, Fowles, & Krueger, 2009) was formulated to reconcile contrasting conceptions of psychopathy reflected in historic writings and contemporary assessment instruments, and to address persisting unresolved issues in the field. The model conceives of psychopathy as encompassing three distinct but interrelated phenotypic dispositions--disinhibition, boldness, and meanness--with biological referents. These dispositional constructs can be viewed as building blocks for alternative conceptions of psychopathy, and various existing psychopathy measures are presumed to index these constructs to differing degrees. This article summarizes the bases of the triarchic model in the conceptual and empirical literatures on psychopathy, and it describes linkages between the constructs of the model and established structural frameworks for personality and psychological disorders. Alternative methods for indexing the constructs of the model are described, and evidence regarding their interrelations and criterion-related validity is reviewed. Promising aspects of the model for ongoing research on psychopathy are discussed, along with current gaps in knowledge/methods and recommended avenues for future research.

The major aim of this study was to evaluate the factor structure of the Italian translation of the Levenson Self-Report Psychopathy Scale (LSRP) in a sample of 740 community dwelling adult participants. Hull method, minimum average partial analysis and quasi-inferential parallel analysis techniques were used to identify a three-factor solution that appeared broadly consistent with previous work. The three factors exhibited reliability coefficients >0.70, and the three-factor structure was adequately reproduced across gender, educational level and civil status strata (median congruence coefficients = 0.94, 0.93 and 0.95 respectively) and remained largely unchanged when the effect of participants' age was controlled for (median factor score correlation = 0.99). Although Factor 3 in our study was demarcated mainly by reverse-keyed items, the LSRP factors yielded meaningful relations with retrospective measures of antisocial behaviour in adolescence and HEXACO personality traits and were conceptually consistent with the triarchic model of psychopathy of Patrick, Fowles and Krueger (2009). Copyright © 2014 John Wiley & Sons, Ltd.

We sought to address inconsistencies in the literature on amplitude of P3 brain potential response in offenders diagnosed with psychopathy. These inconsistencies contrast with the reliable finding of reduced P3 in relation to externalizing tendencies, which overlap with impulsive-antisocial features of psychopathy, as distinguished from the affective-interpersonal features. Employing a sample of incarcerated male offenders (N = 154) who completed the Psychopathy Checklist-Revised along with a three-stimulus visual oddball task, we tested the hypothesis that impulsive-antisocial features of psychopathy would selectively exhibit an inverse relationship with P3 amplitude. Clear support for this hypothesis was obtained. Our findings clarify the discrepant findings regarding psychopathy and P3, and establish P3 as a neurophysiological point of contact between psychopathy and externalizing proneness from the broader psychopathology literature.

The role of the two dimensions of psychopathy—dispositional fearlessness (theorized to reflect variations in reactivity of the brain’s defensive system) and externalizing proneness (presumed to reflect variations in function of anterior regulatory systems)—in fear learning was examined in a sample of undergraduates assessed using the Psychopathic Personality Inventory-Revised (PPI-R) who participated in a differential aversive conditioning task. Only scores on self-reported “fearless dominance,” irrespective of scores on “impulsive antisociality,” were related to diminished acquisition of physiological fear. Consistent with dual-process accounts of psychopathy proposing divergent etiological pathways for the interpersonal/affective and the social deviance features of the disorder, our results lend support to the existence of a deficit in reactivity of the brain’s defensive system underlying the fearlessness dimension of psychopathy. Descriptors: Psychopathy, Aversive conditioning, Skin conductance, Psychopathic Personality Inventory-Revised, Fearlessness

The externalizing dimension is viewed as a broad dispositional factor underlying risk for numerous disinhibitory disorders. Prior work has documented deficits in event-related brain potential (ERP) responses in individuals prone to externalizing problems. Here, we constructed a direct physiological index of externalizing vulnerability from three ERP indicators and evaluated its validity in relation to criterion measures in two distinct domains: psychometric and physiological. The index was derived from three ERP measures that covaried in their relations with externalizing proneness-the error-related negativity and two variants of the P3. Scores on this ERP composite predicted psychometric criterion variables and accounted for externalizing-related variance in P3 response from a separate task. These findings illustrate how a diagnostic construct can be operationalized as a composite (multivariate) psychophysiological variable (phenotype).

Psychopathy is a personality disorder with interpersonal-emotional and antisocial deviance facets. This study investigated these facets of psychopathy prospectively using normal-range personality traits in a community sample of young adult men who completed a picture-viewing task that included startle blink and skin conductance measures, like tasks used to study psychopathy in incarcerated men. Consistent with prior research, scores on the interpersonal-emotional facet of psychopathy ("fearless dominance") were associated with deficient fear-potentiated startle. Conversely, scores on the social deviance facet of psychopathy ("impulsive antisociality") were associated with smaller overall skin conductance magnitudes. Participants high in fearless dominance also exhibited deficient skin conductance magnitudes specifically to aversive pictures. Findings encourage further investigation of psychopathy and its etiology in community samples.

A large literature now exists on emotional modulation of the startle blink reflex. The current study examined affective modulation of the post-auricular reflex, which can be measured in relation to the same noise probe used to evoke the startle reflex. We recorded the post-auricular reflex during viewing of pictures that varied systematically in emotional valence, content, and intensity. A significant linear valence modulation effect was found, with pleasant pictures potentiating and aversive pictures inhibiting the post-auricular reflex in comparison with neutral pictures. This modulatory effect did not vary as a function of picture content, but it was most robust for highly intense emotional pictures. Implications for the assessment of basic emotional action tendencies are discussed.

Background The association between antisocial behavior and alcohol problems is well established, but the role that psychopathic traits and other factors such as drinking patterns and motives and family history play in this relationship has not been subjected to much empirical scrutiny. Methods A large sample (n= 329) of male Federal Correctional Institution inmates participated in structured interviews designed to permit diagnosis of antisocial personality disorder and to assess facets of psychopathic personality as defined by the Hare Psychopathy Checklist–Revised. Prisoners also completed self-report questionnaires that addressed alcohol use, drinking problems, motives for drinking, and paternal alcoholism history. Results Analyses revealed that the relation between antisocial behavior and alcohol problems was moderated by scores on the emotional detachment component of psychopathy, and that self-descriptions of drinking for the purpose of coping with negative emotions mediated the positive relation between antisociality and self-reported alcohol problems. Conclusions These findings highlight complexities in the link between antisociality and drinking problems and encourage consideration of distinct facets of psychopathy to enhance understanding of it. They further suggest possible mechanisms (e.g., paternal alcoholism history, coping motives) that may contribute to the development and maintenance of alcohol problems in criminal populations.

This ground-breaking series of articles reports findings from genome-wide analyses of endophenotypic indicators of psychopathology including electrocortical activity/reactivity, electrodermal and startle blink responses, and neurocognitive task performance. Findings challenge the long-held notion that endophenotypes more clearly reflect the impact of specific genes than referent clinical phenotypes. Implications for the concept of endophenotypes and biological psychopathology research more broadly are discussed.