199 research outputs found

    Understanding jumping to conclusions in patients with persecutory delusions: working memory and intolerance of uncertainty

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    Background. Persecutory delusions are a key psychotic experience. A reasoning style known as ‘jumping to conclusions’ (JTC) – limited information gathering before reaching certainty in decision making – has been identified as a contributory factor in the occurrence of delusions. The cognitive processes that underpin JTC need to be determined in order to develop effective interventions for delusions. In the current study two alternative perspectives were tested: that JTC partially results from impairment in information-processing capabilities and that JTC is a motivated strategy to avoid uncertainty.Method. A group of 123 patients with persistent persecutory delusions completed assessments of JTC (the 60:40 beads task), IQ, working memory, intolerance of uncertainty, and psychiatric symptoms. Patients showing JTC were compared with patients not showing JTC.Results. A total of 30 (24%) patients with delusions showed JTC. There were no differences between patients who did and did not jump to conclusions in overall psychopathology. Patients who jumped to conclusions had poorer working memory performance, lower IQ, lower intolerance of uncertainty and lower levels of worry.Working memory and worry independently predicted the presence of JTC.Conclusions. Hasty decision making in patients with delusions may partly arise from difficulties in keeping information in mind. Interventions for JTC are likely to benefit from addressing working memory performance, while in vivo techniques for patients with delusions will benefit from limiting the demands on working memory. The study provides little evidence for a contribution to JTC from top down motivational beliefs about uncertainty

    The Dynamics of Dense Cores in the Perseus Molecular Cloud II: The Relationship Between Dense Cores and the Cloud

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    We utilize the extensive datasets available for the Perseus molecular cloud to analyze the relationship between the kinematics of small-scale dense cores and the larger structures in which they are embedded. The kinematic measures presented here can be used in conjunction with those discussed in our previous work as strong observational constraints that numerical simulations (or analytic models) of star formation should match. We find that dense cores have small motions with respect to the 13CO gas, about one third of the 13CO velocity dispersion along the same line of sight. Within each extinction region, the core-to-core velocity dispersion is about half of the total (13CO) velocity dispersion seen in the region. Large-scale velocity gradients account for roughly half of the total velocity dispersion in each region, similar to what is predicted from large-scale turbulent modes following a power spectrum of P(k) ~ k^{-4}.Comment: Accepted for publication in ApJ. 47 pages (preprint format), 20 figures, 5 table

    The Gas Temperature of Starless Cores in Perseus

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    In this paper we study the determinants of starless core temperatures in the Perseus molecular cloud. We use NH3 (1,1) and (2,2) observations to derive core temperatures (T_kin) and data from the COMPLETE Survey of Star Forming Regions and the c2d Spitzer Legacy Survey for observations of the other core and molecular cloud properties. The kinetic temperature distribution probed by NH3 is in the fairly narrow range of 9 - 15 K. We find that cores within the clusters IC348 and NGC1333 are significantly warmer than "field" starless cores, and T_kin is higher within regions of larger extinction-derived column density. Starless cores in the field are warmer when they are closer to class O/I protostars, but this effect is not seen for those cores in clusters. For field starless cores, T_kin is higher in regions in which the 13CO linewidth and the 1.1mm flux from the core are larger, and T_kin is lower when the the peak column density within the core and average volume density of the core are larger. There is no correlation between T_kin and 13CO linewidth, 1.1mm flux, density or peak column density for those cores in clusters. The temperature of the cloud material along the line of sight to the core, as measured by CO or far-infrared emission from dust, is positively correlated with core temperature when considering the collection of cores in the field and in clusters, but this effect is not apparent when the two subsamples of cores are considered separately.Comment: Accepted to ApJ; 13 pages, including 3 tables and three figure

    Outflow - Core Interaction in Barnard 1

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    In order to study how outflows from protostars influence the physical and chemical conditions of the parent molecular cloud, we have observed Barnard 1 (B1) main core, which harbors four Class 0 and three Class I sources, in the CO (J=1-0), CH3OH (J_K=2_K-1_K), and the SiO (J=1-0) lines using the Nobeyama 45 m telescope. We have identified three CO outflows in this region; one is an elongated (~ 0.3 pc) bipolar outflow from a Class 0 protostar B1-c in the submillimeter clump SMM 2, another is a rather compact (~ 0.1 pc) outflow from a Class I protostar B1 IRS in the clump SMM 6, and the other is an extended outflow from a Class I protostar in SMM 11. In the western lobe of the SMM 2 outflow, both the SiO and CH3OH lines show broad redshifted wings with the terminal velocities of 25 km/s and 13 km/s, respectively. It is likely that the shocks caused by the interaction between the outflow and ambient gas enhance the abundance of SiO and CH3OH in the gas phase. The total energy input rate by the outflows (1.1x10^{-3} Lsun) is smaller than the energy loss rate (8.5x10^{-3} Lsun$) through the turbulence decay in B1 main core, which suggests that the outflows can not sustain the turbulence in this region. Since the outflows are energetic enough to compensate the dissipating turbulence energy in the neighboring, more evolved star forming region NGC 1333, we suggest that the turbulence energy balance depends on the evolutionary state of the star formation in molecular clouds.Comment: 34 pages, 8 figures, accepted for the publication in Ap

    Dense Gas Tracers in Perseus: Relating the N2H+, NH3, and Dust Continuum Properties of Pre- and Proto-Stellar Cores

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    We investigate 35 pre-stellar cores and 36 proto-stellar cores in the Perseus molecular cloud. We find a very tight correlation between the physical parameters describing the N2H+ and NH3 gas. Both the velocity centroids and the line widths of N2H+ and NH3 correlate much better than either species correlates with CO, as expected if the nitrogen-bearing species are probing primarily the dense core gas where the CO has been depleted. We also find a tight correlation in the inferred abundance ratio between N2H+ and para-NH3 across all cores, with N(p-NH3)/N(N2H+)= 22 +/- 10. We find a mild correlation between NH3 (and N2H+) column density and the (sub)millimeter dust continuum derived H2 column density for pre-stellar cores, N(p-NH3)/N(H2) ~ 10e-8, but do not find a fixed ratio for proto-stellar cores. The observations suggest that in the Perseus molecular cloud the formation and destruction mechanisms for the two nitrogen-bearing species are similar, regardless of the physical conditions in the dense core gas. While the equivalence of N2H+ and NH3 as powerful tracers of dense gas is validated, the lack of correspondence between these species and the (sub)millimeter dust continuum observations for proto-stellar cores is disconcerting and presently unexplained.Comment: ApJ accepted. 45 pages, 8 figure

    A shallow though extensive H2 2.12 micron imaging survey of Taurus-Auriga-Perseus: I. NGC1333, L1455, L1448 and B1

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    We discuss wide-field near-IR imaging of the NGC1333, L1448, L1455 and B1 star forming regions in Perseus. The observations have been extracted from a much larger narrow-band imaging survey of the Taurus-Auriga-Perseus complex. These H2 2.12 micron observations are complemented by broad-band K imaging, mid-IR imaging and photometry from the Spitzer Space Telescope, and published submillimetre CO J=3-2 maps of high-velocity molecular outflows. We detect and label 85 H2 features and associate these with 26 molecular outflows. Three are parsec-scale flows, with a mean flow lobe length exceeding 11.5 arcmin. 37 (44%) of the detected H2 features are associated with a known Herbig-Haro object, while 72 (46%) of catalogued HH objects are detected in H2 emission. Embedded Spitzer sources are identified for all but two of the 26 molecular outflows. These candidate outflow sources all have high near-to-mid-IR spectral indices (mean value of alpha ~ 1.4) as well as red IRAC 3.6-4.5 micron and IRAC/MIPS 4.5-24.0 micron colours: 80% have [3.6]-[4.5] > 1.0 and [4.5]-[24] > 1.5. These criteria - high alpha and red [4.5]-[24] and [3.6]-[4.5] colours - are powerful discriminants when searching for molecular outflow sources. However, we find no correlation between alpha and flow length or opening angle, and the outflows appear randomly orientated in each region. The more massive clouds are associated with a greater number of outflows, which suggests that the star formation efficiency is roughly the same in each region.Comment: 23 pages (including Appoendix); 11 main text figures, 5 colour appendix figs uploaded as gifs; accepted by MNRAS; for higher-resolution figures please visit http://www.jach.hawaii.edu/~cdavis

    Developing a new measure of dissociation: The Dissociative Experiences Measure, Oxford (DEMO)

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    The field of dissociation is receiving increasing attention, despite a lack of coherent conceptualisation of the construct. Advances in the field would be aided by a measure that reflects service user experiences of dissociative experiences and can be easily scored. The current study describes the development of a new measure of dissociation (Dissociative Experiences Measure, Oxford; DEMO) that aims to fulfil these criteria. The study follows an exploratory, data-driven, measure development design. Resource searching and feedback from clinicians (n = 3) and service users (n = 6) were used to develop an extensive item pool. An online sample (n = 691) provided data for a factor analysis of the item pool. Factor analysis produced a measure with five subscales: ‘unreality’, ‘numb and disconnected’, ‘memory blanks’, ‘zoned out’, and ‘vivid internal world’. Further analysis indicated that the new measure has high internal consistency, and high convergent, divergent, and discriminant validity. The DEMO shows promise as an up-to-date clinical and research tool for the assessment of dissociative experiences. These results are preliminary, and further validation of the measure with a clinical sample is required

    The relationship between dissociation and panic symptoms in adolescence and the exploration of potential mediators

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    Background: Dissociative experiences have been linked to panic symptoms in adolescents, yet the nature of the association remains unclear. Methods: In the present study, we investigated the longitudinal relationship between dissociative experiences (focusing on the felt sense of anomaly subtype) and panic, as well as the potential mediating roles of emotion regulation strategies (expressive suppression and cognitive reappraisal), alexithymia, and cognitive appraisals of dissociation. Four thousand five hundred one adolescents aged 13–18 years were recruited via social media advertising to take part in an online survey at two timepoints, 1 month apart. Results: Analysis of 421 datasets found a significant positive relationship between initial dissociative experiences and panic symptoms reported 1 month later. This was mediated by the emotion regulation strategy of cognitive reappraisal, and cognitive appraisals of dissociation. These two variables were no longer significant mediators when controlling for panic symptoms at the first time point, likely due to the stability of panic symptoms across both assessments. Neither alexithymia nor expressive suppression were significant mediators. Conclusions: Thus, dissociative experiences that are persistently misinterpreted in a catastrophic manner may lead to escalating anxiety and panic symptoms, which could in turn heighten and maintain the feared dissociation sensation. These results indicate that dissociative experiences are associated with panic symptoms in adolescence, with cognitive appraisals of dissociation and cognitive reappraisal playing a role in this relationship

    The Černis Felt Sense of Anomaly (ČEFSA) Scale:Psychometric Properties and Validity of a German Version

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    Past research on dissociation has predominantly relied on broad questionnaires, presenting ambiguous and overlapping themes in describing dissociative experiences. A new measure, the Černis Felt Sense of Anomaly (ČEFSA) scale (Černis et al., 2021), assesses a subgroup of dissociative experiences where felt sense of anomaly is inherent. In this article, we present a German translation of the 35-item ČEFSA scale. In Study 1 (N = 130), we investigated the factor structure of the initial translation. We describe how necessary revisions were implemented. In Study 2 (N = 243), we show that the seven ČEFSA subscales had an appropriate factor structure and sufficient reliability. In terms of validity, the convergent, discriminant, and criterion correlations were mostly as expected. Some subscales showed high intercorrelations, making it difficult to distinguish them. We conclude that the German version of the ČEFSA scale provides a reliable and valid tool for the detailed assessment of dissociation
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