11 results
Patients with psychotic disorders exhibit different audio-visual perceptual decision biases and metacognitive abilities
- L. Franzen, S. Eickhoff, H. Schewe, L. M. Schmitt, J. Erb, S. Borgwardt, C. Andreou, J. Obleser
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- Journal:
- European Psychiatry / Volume 66 / Issue S1 / March 2023
- Published online by Cambridge University Press:
- 19 July 2023, pp. S129-S130
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Introduction
In the inherently noisy real world, we can rarely have full certainty about what we have just seen or heard. Thus, making a perceptual decision on sensory information, and simultaneously tracking our varying levels of certainty in these decisions (i.e., metacognitive abilities) are crucial components of everyday life.
Hallucinations, such as confidently reporting a human voice or face when none was present, are a hallmark of psychotic disorders but also occur among the normal population. Particularly in patients with psychotic disorders, these misperceptions are linked to confident beliefs in their actual existence. However, whether patients’ confidence is only increased during such erroneous perceptions and whether perceptual and metacognitive decisions arise from supramodal mechanisms across sensory modalities remains unknown.
ObjectivesIn the laboratory, we tested perceptual and metacognitive decisions under varying levels of sensory certainty in healthy adults and patients with psychotic disorders admitted to a psychiatry ward (Ncon=32, Npat=12; age = 19-49; F2x.x diagnoses).
MethodsSpecifically, participants had to detect human voices or faces against briefly presented noisy backdrops and subsequently rate their confidence in the accuracy of their perceptual decision (Fig 1A,B,C). We further hypothesised that probabilistic cues prior to blocks of trials can bias participants’ choices and hallucination probability (i.e., confident false alarms).
ResultsPatients exhibited higher perceptual sensitivity in the auditory than the visual task, alongside a generally stronger decision bias towards fewer ‘voice/face’ choices (Fig 2A,B). This bias was more pronounced in the visual domain. Decision performance was overall higher on the auditory task but lower for patients (predicted minimum > 55%; Fig 2C). Strong correlations between auditory accuracy and PANSS hallucination scores of patients and LSHS scores of healthy participants suggest an effect of these hallucinatory experiences on accurate perception.
Metacognitive abilities were reduced in patients across both modalities: They exhibited general overconfidence, which was stronger for incorrect trials (Fig 3A). Patients’ confidence ratings were inversely related to the probability of choosing ‘voice/face’. Combining both perceptual and confidence decisions, patients showed higher hallucinations probability in the auditory task, particularly in more difficult trials (i.e., with less informative sensory evidence; Fig 3B).
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ConclusionsIn sum, patients with psychotic disorders exhibit increased decision bias accompanied by increased confidence, and thus a reduced fidelity in their metacognitive abilities. The modality differences are in line with phenomenology and reported hallucination rates. These results suggest stronger priors in psychotic disorders resulting in worse perceptual acuity and assessment of this perception.
Disclosure of InterestNone Declared
The Effect of Exercise Deprivation on the Behaviour and Physiology of Straight Stall Confined Pregnant Mares
- K Houpt, T R Houpt, J L Johnson, H N Erb, S C Yeon
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- Animal Welfare / Volume 10 / Issue 3 / August 2001
- Published online by Cambridge University Press:
- 11 January 2023, pp. 257-267
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The purpose of this experiment was to investigate the welfare of pregnant mares kept in straight stalls and given only limited exercise, conditions that are similar to those encountered in the pregnant mare urine industry. Sixteen pregnant mares (eight in each of two years) were randomly assigned to two groups: Ex (exercised in a paddock for 30 min per day) or NoEx (exercised for one 30 min period every 14 days). The horses were housed in straight (or ‘tie’) stalls for six months and had ad libitum access to grass hay. Each horse's behaviour was recorded on videotape once per week for 24 h. The major behaviours were eating hay, standing, and stand-resting (head down and one hind limb flexed). There was no difference between the behaviours or the number of foot lifts per min of the Ex and NoEx groups in their stalls. Nine of 16 mares were not observed in recumbency throughout the whole of the six-month observation period, suggesting that horses with no previous experience in straight stalls may be reluctant to lie down. Thirteen of 16 mares dropped to their knees at least once, probably when they were REM sleeping while standing. There were no significant differences between the Ex and the NoEx mares in baseline plasma Cortisol levels or in Cortisol response to ACTH. Following 30 min of exercise, NoEx mares showed an increase in Cortisol from 5.0 to 5.4 μg dL−1, whereas Ex mares showed a decrease from 4.6 to 3.6 µg dL−1. The NoEx horses that had been confined for two weeks trotted more (NoEx = 22 [6-38; median and range]% of time; Ex = 2.4 [0-8.7]%) and galloped more (NoEx = 6 [2-8]%; Ex = 0 [0-4]%) than the Ex that were released daily, but walked less (NoEx = 17 [10-26]%; Ex = 35 [20-40]%) and grazed less (NoEx = 0%; Ex = 3 [0-12]%). Confined horses show rebound locomotion — that is, a compensatory increase — when released from confinement, indicating a response to exercise deprivation.
Contributors
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- By Rose Teteki Abbey, K. C. Abraham, David Tuesday Adamo, LeRoy H. Aden, Efrain Agosto, Victor Aguilan, Gillian T. W. Ahlgren, Charanjit Kaur AjitSingh, Dorothy B E A Akoto, Giuseppe Alberigo, Daniel E. Albrecht, Ruth Albrecht, Daniel O. Aleshire, Urs Altermatt, Anand Amaladass, Michael Amaladoss, James N. Amanze, Lesley G. Anderson, Thomas C. Anderson, Victor Anderson, Hope S. Antone, María Pilar Aquino, Paula Arai, Victorio Araya Guillén, S. Wesley Ariarajah, Ellen T. Armour, Brett Gregory Armstrong, Atsuhiro Asano, Naim Stifan Ateek, Mahmoud Ayoub, John Alembillah Azumah, Mercedes L. García Bachmann, Irena Backus, J. Wayne Baker, Mieke Bal, Lewis V. Baldwin, William Barbieri, António Barbosa da Silva, David Basinger, Bolaji Olukemi Bateye, Oswald Bayer, Daniel H. Bays, Rosalie Beck, Nancy Elizabeth Bedford, Guy-Thomas Bedouelle, Chorbishop Seely Beggiani, Wolfgang Behringer, Christopher M. Bellitto, Byard Bennett, Harold V. Bennett, Teresa Berger, Miguel A. Bernad, Henley Bernard, Alan E. Bernstein, Jon L. Berquist, Johannes Beutler, Ana María Bidegain, Matthew P. Binkewicz, Jennifer Bird, Joseph Blenkinsopp, Dmytro Bondarenko, Paulo Bonfatti, Riet en Pim Bons-Storm, Jessica A. Boon, Marcus J. Borg, Mark Bosco, Peter C. Bouteneff, François Bovon, William D. Bowman, Paul S. Boyer, David Brakke, Richard E. Brantley, Marcus Braybrooke, Ian Breward, Ênio José da Costa Brito, Jewel Spears Brooker, Johannes Brosseder, Nicholas Canfield Read Brown, Robert F. Brown, Pamela K. Brubaker, Walter Brueggemann, Bishop Colin O. Buchanan, Stanley M. Burgess, Amy Nelson Burnett, J. Patout Burns, David B. Burrell, David Buttrick, James P. Byrd, Lavinia Byrne, Gerado Caetano, Marcos Caldas, Alkiviadis Calivas, William J. Callahan, Salvatore Calomino, Euan K. Cameron, William S. Campbell, Marcelo Ayres Camurça, Daniel F. Caner, Paul E. Capetz, Carlos F. Cardoza-Orlandi, Patrick W. Carey, Barbara Carvill, Hal Cauthron, Subhadra Mitra Channa, Mark D. Chapman, James H. Charlesworth, Kenneth R. Chase, Chen Zemin, Luciano Chianeque, Philip Chia Phin Yin, Francisca H. Chimhanda, Daniel Chiquete, John T. Chirban, Soobin Choi, Robert Choquette, Mita Choudhury, Gerald Christianson, John Chryssavgis, Sejong Chun, Esther Chung-Kim, Charles M. A. Clark, Elizabeth A. Clark, Sathianathan Clarke, Fred Cloud, John B. Cobb, W. Owen Cole, John A Coleman, John J. Collins, Sylvia Collins-Mayo, Paul K. Conkin, Beth A. Conklin, Sean Connolly, Demetrios J. Constantelos, Michael A. Conway, Paula M. Cooey, Austin Cooper, Michael L. Cooper-White, Pamela Cooper-White, L. William Countryman, Sérgio Coutinho, Pamela Couture, Shannon Craigo-Snell, James L. Crenshaw, David Crowner, Humberto Horacio Cucchetti, Lawrence S. Cunningham, Elizabeth Mason Currier, Emmanuel Cutrone, Mary L. Daniel, David D. Daniels, Robert Darden, Rolf Darge, Isaiah Dau, Jeffry C. Davis, Jane Dawson, Valentin Dedji, John W. de Gruchy, Paul DeHart, Wendy J. 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Yee, Viktor Yelensky, Yeo Khiok-Khng, Gustav K. K. Yeung, Angela Yiu, Amos Yong, Yong Ting Jin, You Bin, Youhanna Nessim Youssef, Eliana Yunes, Robert Michael Zaller, Valarie H. Ziegler, Barbara Brown Zikmund, Joyce Ann Zimmerman, Aurora Zlotnik, Zhuo Xinping
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- The Cambridge Dictionary of Christianity
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- 05 August 2012
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- 20 September 2010, pp xi-xliv
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Thienopyrazine-based low-bandgap polymers for flexible polymer solar cells
- S. Sensfuss, L. Blankenburg, H. Schache, S. Shokhovets, T. Erb, A. Konkin, A. Herasimovich, S. Scheinert, M. Shahid, S. Sell, E. Klemm
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- The European Physical Journal - Applied Physics / Volume 51 / Issue 3 / September 2010
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- 02 September 2010, 33204
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- September 2010
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The optical gaps of the low-bandgap PPVs (PM-20, PM-19, PM-18) are decreased down to 1.6-1.7 eV compared with that of MDMO-PPV (2.2 eV). The best lateral hole mobility was determined to be 2.1 × 10-3 cm2/V s (PM-18) in field effect transistors and exceeds that of MDMO-PPV (poly-[ 2-methoxy-5-(3'.7'-dimethyloctyloxy)-1.4-phenylenevinylene], 8.5 × 10-4 cm2/V s). This allows to reduce the PCBM ([6.6]-phenyl-C$_{61(71)}$-butanoic acid methyl ester) content in solar cell devices down to 1:2 w/w giving a better $\eta_{\rm AM1.5}$ than for MDMO-PPV:[60]-PCBM cells (PM-19:[60]-PCBM 2.32% on ITO-PET, 2.86% on ITO glass). The charge transfer to PCBM as acceptor occurs quite normally and shows an effective charge separation using light-induced spin resonance spectroscopy (LESR). The [70]-PCBM$^{-\bullet}$ signals are shifted to lower field related to those of [60]-PCBM$^{-\bullet}$ and overlap more with the polaron signal of PM-19. The LESR g-factor components of [70]-PCBM$^{-\bullet}$ are reported for the first time. The external quantum efficiency peak values achieve up to 42% at ~350–400 nm and 26% at ~640 nm (PM-19:[60]-PCBM).
Comparison principles for impulsive parabolic equations with applications to models of single species growth
- L. H. Erbe, H. I. Freedman, X. Z. Liu, J. H. Wu
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- Journal of the Australian Mathematical Society. Series B. Applied Mathematics / Volume 32 / Issue 4 / April 1991
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- 17 February 2009, pp. 382-400
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This paper establishes some maximum and comparison principles relative to lower and upper solutions of nonlinear parabolic partial differential equations with impulsive effects. These principles are applied to obtain some sufficient conditions for the global asymptotic stability of a unique positive equilibrium in a reaction-diffusion equation modeling the growth of a single-species population subject to abrupt changes of certain important system parameters.
Nonoscillation of Second Order Superlinear Differential Equations
- L. H. Erbe, H. X. Xia, J. H. Wu
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- Canadian Mathematical Bulletin / Volume 37 / Issue 2 / 01 June 1994
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- 20 November 2018, pp. 178-186
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- 01 June 1994
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Some sufficient conditions are given for all solutions of the nonlinear differential equation y″(x) +p(x)f(y) = 0 to be nonoscillatory, where p is positive and
for a quotient γ of odd positive integers, γ > 1.
Oscillation and Nonoscillation Properties of Neutral Differential Equations
- L. H. Erbe, Qingkai Kong
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- Canadian Journal of Mathematics / Volume 46 / Issue 2 / 01 April 1994
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- 20 November 2018, pp. 284-297
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- 01 April 1994
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We obtain a number of new conditions for oscillation of the first order neutral delay equation with nonconstant coefficients of the form
Comparison results are also given as well as conditions for the existence of nonoscillatory solutions.
Equivariant Fixed Point Index and the Period-Doubling Cascades
- L. H. Erbe, K. Gęba, W. Krawcewicz
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- Journal:
- Canadian Journal of Mathematics / Volume 43 / Issue 4 / 01 August 1991
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- 20 November 2018, pp. 738-747
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- 01 August 1991
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Properties of fixed points of equivariant maps have been studied by several authors including A. Dold (cf. [2], 1982), H. Ulrich (cf. [9], 1988), A. Marzantowicz (cf. [7], 1975) and others. Closely related is the work of R. Rubinsztein (cf. [8], 1976) in which he investigated homotopy classes of equivariant maps between spheres. There have been many attempts to introduce and effectively apply these concepts to nonlinear problems. In particular we mention the work of E. Dancer (cf. [1], 1982) in which some applications to nonlinear problems are given.
Solvability of boundary value problems for vector differential systems*
- L. H. Erbe, Xinzhi Liu, Jianhong Wu
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- Journal:
- Proceedings of the Royal Society of Edinburgh. Section A: Mathematics / Volume 114 / Issue 3-4 / 1990
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- 14 November 2011, pp. 181-193
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- 1990
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Brouwer topological degree theory, the shooting type method, the disconjugacy theory of Hamiltonian systems and the Liapunov-Razumikhin technique of Volterra integrodifferential equations are employed to establish some solvability results for the 2n-dimensional differential system
subject to one of the following boundary conditions:
(i) x(0) = Qx(l), Qg(l x(1), qy(1)= g(0, x(0), y(0)),
(ii) Blx(O) = B2g(O, x(O), y(O)), C1x(l) = −C2g(l, x(l), y(l)),
where Q, Bi, Ci, i = 1, 2, are n x n real matrices. An application is given to the second order equation xn = h(t, x, x') subject to certain nonlinear boundary conditions.
Boundary value problems for systems of second order differential equations
- L. H. Erbe, H. W. Knobloch
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- Proceedings of the Royal Society of Edinburgh. Section A: Mathematics / Volume 101 / Issue 1-2 / 1985
- Published online by Cambridge University Press:
- 14 November 2011, pp. 61-76
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- 1985
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We consider boundary value problems for second order differential systems of the form (1)x” = A(t)x′ + f(t, x) and (2) x” = A(t)x′ + f(t, x) + q(t, x). By assuming the existence of a solution to (1) with a given region in (t, x) space, we derive conditions under which there exists a solution to (2) which stays in a certain neighbourhood of and satisfies given boundary conditions.
On the Non-Existence of Conjugate Points
- G. J. Butler, L. H. Erbe, R. M. Mathsen
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- Journal:
- Canadian Mathematical Bulletin / Volume 13 / Issue 1 / March 1970
- Published online by Cambridge University Press:
- 20 November 2018, pp. 31-37
- Print publication:
- March 1970
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- Article
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In this paper we consider the types of pairs of multiple zeros which a solution to the differential equation
can possess on an interval I of the real line. The results obtained generalize those in [2] and (for n = 3) in [3].
I. Let f satisfy the condition
1.1
for all t ∊ I, u0 ≠ 0, and all u1, … un-1.