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1.
Nanoscale Adv ; 5(18): 4696-4702, 2023 Sep 12.
Article in English | MEDLINE | ID: mdl-37705792

ABSTRACT

Germanium (Ge) is increasingly used as a substrate for high-performance optoelectronics, photovoltaics, and electronic devices. These devices are usually grown on thick and rigid Ge substrates manufactured by classical wafering techniques. Nanomembranes (NMs) provide an alternative to this approach while offering wafer-scale lateral dimensions, weight reduction, waste limitation, and cost effectiveness. Herein, we introduce the Porous germanium Efficient Epitaxial LayEr Release (PEELER) process, which consists of the fabrication of wafer-scale detachable Ge NMs on porous Ge (PGe) and substrate reuse. We demonstrate the growth of Ge NMs with monocrystalline quality as revealed by high-resolution transmission electron microscopy (HRTEM) characterization. Together with the surface roughness below 1 nm, it makes the Ge NMs suitable for growth of III-V materials. Additionally, the embedded nanoengineered weak layer enables the detachment of the Ge NMs. Finally, we demonstrate the wet-etch-reconditioning process of the Ge substrate, allowing its reuse, to produce multiple free-standing NMs from a single parent wafer. The PEELER process significantly reduces the consumption of Ge in the fabrication process, paving the way for a new generation of low-cost flexible optoelectronic devices.

2.
Water Environ Res ; 95(4): e10853, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36945738

ABSTRACT

An approach to remove ammonia from mining wastewater is to precipitate ammonia into struvite, and flocculation was proved to enhance settling of struvite flocs. But the current literature fails to consider flocculent properties of struvite flocs, and previous studies focused only on small volumes. This study evaluates the effect of ammonia concentration and height on removal efficiency of struvite flocs in a batch system and compares removal efficiency of struvite flocs between a batch and a pilot-scale continuous settling process to evaluate the potential of using flocculation to recover struvite crystals as a stand-alone method. Removal efficiency of struvite using flocculation is evaluated depending on depth in a batch system for two different ammonia concentrations (45 and 90 ppm) and in a continuous system for different flowrates. It is shown that a higher concentration promotes flocculation and enhances settling velocities of struvite flocs. The difference between the batch and the continuous processes for the same removal efficiency was significantly higher from what has been reported in the literature: in the continuous process, 89% of struvite flocs have been recovered with a surface overflow rate (SOR) of 1.8 m.h-1 , whereas, for the same height, the same efficiency corresponds to SOR = 9 m.h-1 in the batch process. The fragile nature of struvite flocs is potentially responsible for such a difference. PRACTITIONER POINTS: Settling velocities of struvite flocs are highly dependant on concentration and depth. Removal efficiency are considerably higher with a batch settling process for the same surface overflow rate. Flocculation enable 89% of struvite fines to be recovered in a continuous settling process with a SOR of 1.8 m.hs-1 .


Subject(s)
Ammonia , Wastewater , Struvite/chemistry , Flocculation
3.
PeerJ ; 7: e7221, 2019.
Article in English | MEDLINE | ID: mdl-31681508

ABSTRACT

In 2010, the Conference of the Parties of the Convention on Biological Diversity agreed on the Strategic Plan for Biodiversity 2011-2020 in Aichi Prefecture, Japan. As this plan approaches its end, we discussed whether marine biodiversity and prediction studies were nearing the Aichi Targets during the 4th World Conference on Marine Biodiversity held in Montreal, Canada in June 2018. This article summarises the outcome of a five-day group discussion on how global marine biodiversity studies should be focused further to better understand the patterns of biodiversity. We discussed and reviewed seven fundamental biodiversity priorities related to nine Aichi Targets focusing on global biodiversity discovery and predictions to improve and enhance biodiversity data standards (quantity and quality), tools and techniques, spatial and temporal scale framing, and stewardship and dissemination. We discuss how identifying biodiversity knowledge gaps and promoting efforts have and will reduce such gaps, including via the use of new databases, tools and technology, and how these resources could be improved in the future. The group recognised significant progress toward Target 19 in relation to scientific knowledge, but negligible progress with regard to Targets 6 to 13 which aimed to safeguard and reduce human impacts on biodiversity.

4.
PLoS Comput Biol ; 14(8): e1006191, 2018 08.
Article in English | MEDLINE | ID: mdl-30161124

ABSTRACT

Workshops are used to explore a specific topic, to transfer knowledge, to solve identified problems, or to create something new. In funded research projects and other research endeavours, workshops are the mechanism used to gather the wider project, community, or interested people together around a particular topic. However, natural questions arise: how do we measure the impact of these workshops? Do we know whether they are meeting the goals and objectives we set for them? What indicators should we use? In response to these questions, this paper will outline rules that will improve the measurement of the impact of workshops.


Subject(s)
Education/standards , Humans , Knowledge , Learning , Research , Weights and Measures
5.
J Invest Dermatol ; 137(11): 2316-2325, 2017 11.
Article in English | MEDLINE | ID: mdl-28757138

ABSTRACT

Patients with systemic sclerosis (SSc) display altered intestinal microbiota. However, the influence of intestinal dysbiosis on the development of experimental SSc remains unknown. Topoisomerase I peptide-loaded dendritic cell immunization induces SSc-like disease, with progressive skin and lung fibrosis. Breeders were given streptomycin and pups continued to receive antibiotic (ATB) until endpoint (lifelongATB). Alternately, ATB was withdrawn (earlyATB) or initiated (adultATB) during adulthood. Topoisomerase I peptide-loaded dendritic cell (no ATB) immunization induced pronounced skin fibrosis, with increased matrix (Col1a1), profibrotic (Il13, Tweakr), and vascular function (Serpine1) gene expression. Remarkably, earlyATB exposure was sufficient to augment skin Col5a1 and Il13 expression, and inflammatory cell infiltration, which included IL-13+ cells, mononuclear phagocytes, and mast cells. Moreover, skin pathology exacerbation was also observed in lifelongATB and adultATB groups. Oral streptomycin administration induced intestinal dysbiosis, with exposure limited to early life (earlyATB) being sufficient to cause long-term modification of the microbiota and a shift toward increased Bacteroidetes/Firmicutes ratio. Finally, aggravated lung fibrosis and dysregulated pulmonary T-cell responses were observed in earlyATB and lifelongATB but not adultATB-exposed mice. Collectively, intestinal microbiota manipulation with streptomycin exacerbated pathology in two distinct sites, skin and lungs, with early life being a critical window to affect the course of SSc-like disease.


Subject(s)
Dysbiosis/genetics , Gastrointestinal Microbiome/drug effects , Pulmonary Fibrosis/pathology , Scleroderma, Systemic/genetics , Scleroderma, Systemic/immunology , Streptomycin/pharmacology , Age Factors , Animals , Cells, Cultured , DNA, Bacterial/analysis , Dendritic Cells/drug effects , Disease Models, Animal , Dysbiosis/microbiology , Female , Gastrointestinal Microbiome/genetics , Humans , Male , Mice , Mice, Inbred BALB C , Mice, Transgenic , Pulmonary Fibrosis/genetics , Random Allocation , Real-Time Polymerase Chain Reaction/methods , Risk Factors , Scleroderma, Systemic/pathology , Statistics, Nonparametric
6.
Clin Exp Rheumatol ; 35 Suppl 106(4): 35-39, 2017.
Article in English | MEDLINE | ID: mdl-28229819

ABSTRACT

OBJECTIVES: Dysregulated coagulation cascade has been implicated in development of fibrosis in systemic sclerosis (SSc). Thrombin, a key mediator of the coagulation pathway, has both proinflammatory and procoagulant properties. Here, we evaluated the efficacy of oral dabigatran, a direct thrombin inhibitor, on topoisomerase I dendritic cells (TOPOIA DCs)-induced lung and skin fibrosis, an experimental model of SSc. METHODS: Mice were repeatedly immunized with TOPOIA DCs. Dabigatran was administered in food either during the onset of fibrotic (late treatment) or inflammatory (early treatment) phase. RESULTS: Early administration of dabigatran caused an aggravation of pulmonary fibrosis associated with signs of severe perivascular inflammation while late treatment was not protective when compared to the untreated TOPOIA DCs group. Thrombin was increased in lungs of TOPOIA DCs immunized group and, paradoxically, further augmented by administration of dabigatran to immunized mice. As in lungs, early and not late drug administration exacerbated skin fibrosis. Moreover, early dabigatran treatment induced a profibrotic and inflammatory skin gene expression signature with upregulated expression of Col5a1, Timp1, Tweakr, Vwf, Il6, Il33, Il4 and Ifng. CONCLUSIONS: Dabigatran aggravated lung and skin fibrosis in a TOPOIA DCs-induced model of SSc-like disease. Therefore, our results argue against the use of dabigatran to treat patients with SSc.


Subject(s)
Antithrombins/toxicity , DNA Topoisomerases, Type I/immunology , Dabigatran/toxicity , Dendritic Cells/immunology , Pulmonary Fibrosis/etiology , Scleroderma, Systemic/drug therapy , Skin/pathology , Animals , Female , Fibrosis , Male , Mice
7.
Micromachines (Basel) ; 8(12)2017 Dec 01.
Article in English | MEDLINE | ID: mdl-30400544

ABSTRACT

This work presents a laterally rotating micromachined platform integrated under optical waveguides to control the in-plane propagation direction of light within a die to select one of multiple outputs. The platform is designed to exhibit low constant optical losses throughout the motion range and is actuated electrostatically using an optimized circular comb drive. An angular motion of ±9.5° using 180 V is demonstrated. To minimize the optical losses between the moving and fixed parts, a gap-closing mechanism is implemented to reduce the initial air gap to submicron values. A latch structure is implemented to hold the platform in place with a resolution of 0.25° over the entire motion range. The platform was integrated with silicon nitride waveguides to create a crossbar switch and preliminary optical measurements are reported. In the bar state, the loss was measured to be 14.8 dB with the gap closed whereas in the cross state it was 12.2 dB. To the authors' knowledge, this is the first optical switch based on a rotating microelectromechanical device with integrated silicon nitride waveguides reported to date.

8.
Autoimmunity ; 49(8): 503-513, 2016 12.
Article in English | MEDLINE | ID: mdl-27808577

ABSTRACT

DNA Topoisomerase I (TopoI) is a candidate autoantigen for diffuse cutaneous systemic sclerosis (dcSSc) associated with fatal lung disease. Dendritic cells (DCs) contribute to bleomycin-induced lung fibrosis. However, the possibility that TopoI-loaded DCs are involved in the initiation and/or perpetuation of dcSSc has not been explored. Here, we show that immunization with TopoI peptide-loaded DCs induces anti-TopoI autoantibody response and long-term fibrosis. Mice were repeatedly immunized with unpulsed DCs or DCs loaded with either TOPOIA or TOPOIB peptides, selected from different regions of TopoI. At week 12 after initial DC immunization, TOPOIA DCs but not TOPOIB DCs immunization induced mixed inflammation and fibrosis in lungs and skin. At a late time point (week 18), both TOPOIA DCs and TOPOIB DCs groups displayed increased alpha-smooth muscle actin expression in lungs and dermis along with skin fibrosis distal from the site of injection when compared with unpulsed DCs. Both TopoI peptide-DC-immunized groups developed IgG2a anti-TopoI autoantibody response. At week 10, signs of perivascular, peribronchial, and parenchymal pulmonary inflammation were already observed in the TOPOIA DCs group, together with transient elevation in bronchoalveolar lavage cell counts, IL-17A expression, and CXCL4 production, a biomarker of early human dcSSc. Collectively, TopoI peptide DCs induce progressive autoantibody response as well as development of protracted skin and lung dcSSc-like disease. Pronounced lung inflammation, transient IL-17A, and CXCL4 expression precede fibrosis development. Our immunization strategy, that uses self immune system and autoantigen, will help to further investigate the pathogenesis of this complex autoimmune disorder with unmet medical needs.


Subject(s)
Autoantibodies/immunology , DNA Topoisomerases, Type I/immunology , Dendritic Cells/immunology , Lung/immunology , Lung/pathology , Peptides/immunology , Skin/immunology , Skin/pathology , Actins/metabolism , Animals , Autoimmunity , Biomarkers , Biopsy , Bronchoalveolar Lavage Fluid/immunology , Cytokines/metabolism , DNA Topoisomerases, Type I/chemistry , Dendritic Cells/metabolism , Fibrosis , Immunization , Lung/metabolism , Mice , Skin/metabolism
9.
Schizophr Res Treatment ; 2016: 6371856, 2016.
Article in English | MEDLINE | ID: mdl-27516906

ABSTRACT

Cognitive remediation therapy (CRT) has emerged as a viable treatment option for people diagnosed with schizophrenia presenting disabling cognitive deficits. However, it is important to determine which variables can influence response to CRT in order to provide cost-effective treatment. This study's aim was to explore cognitive insight as a potential predictor of cognitive improvement after CRT. Twenty patients with schizophrenia completed a 24-session CRT program involving 18 hours of computer exercises and 6 hours of group discussion to encourage generalization of cognitive training to everyday activities. Pre- and posttest assessments included the CogState Research Battery and the Beck Cognitive Insight Scale (BCIS). Lower self-certainty on the BCIS at baseline was associated with greater improvement in speed of processing (r s = -0.48; p < 0.05) and visual memory (r s = -0.46; p < 0.05). The results of this study point out potential associations between self-certainty and cognitive improvement after CRT, a variable that can easily be measured in clinical settings to help evaluate which patients may benefit most from the intervention. They also underline the need to keep investigating the predictors of good CRT outcomes, which can vary widely between patients.

10.
Sante Ment Que ; 41(1): 291-311, 2016.
Article in French | MEDLINE | ID: mdl-27570962

ABSTRACT

Background The international prevalence of adult attention deficit hyperactivity disorder (ADHD) is estimated at 2.5%. ADHD is associated with serious impairment in academic, occupational, social and emotional functioning. Despite the debilitating nature of this disorder, few individuals with ADHD receive appropriate help. Further, although psychopharmacology is considered the first-line treatment of adults with ADHD, it is now recognized that medication alone may be insufficient. Thus, cognitive behavioral therapy (CBT) is a promising approach.Objectives This study aimed to review literature and investigate the efficacy of CBT, in reducing ADHD symptoms and comorbid conditions such anxiety and depression for adults with ADHD, by several studies through a meta-analysis.Methods We searched the literature from 1946 through 2015 using especially MEDLINE, EMBASE and PsycINFO. We used a random-effects model, Odds Ratios (OR) and Hedge's g.Results Data from 12 randomized controlled studies were included, totaling 575 subjects. The results showed a significant reduction in ADHD symptoms (Hedge's g = 0.95) and comorbid anxiety (Hedge's g = 0.39) and depression (Hedge's g = 0.30) for the CBT group in comparison with controls. Following the end of treatment, ADHD symptoms continue to improve, but not the comorbid conditions.Conclusion In summary, in adults with ADHD, CBT appears to be a promising treatment.


Subject(s)
Attention Deficit Disorder with Hyperactivity/therapy , Cognitive Behavioral Therapy , Adult , Humans
11.
Soc Cogn Affect Neurosci ; 11(3): 445-57, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26516171

ABSTRACT

Social approval is a reward that uses abstract social reinforcers to guide interpersonal interactions. Few studies have specifically explored social reward processing and its related neural substrates in schizophrenia. Fifteen patients with schizophrenia and fifteen healthy controls participated in a two-part study to explore the functional neural correlates of social approval. In the first session, participants were led to believe their personality would be assessed based on their results from various questionnaires and an interview. Participants were then presented with the results of their supposed evaluation in the scanner, while engaging in a relevant fMRI social approval task. Subjects provided subjective reports of pleasure associated with receiving self-directed positive or negative feedback. Higher activation of the right parietal lobe was found in controls compared with individuals with schizophrenia. Both groups rated traits from the high social reward condition as more pleasurable than the low social reward condition, while intergroup differences emerged in the low social reward condition. Positive correlations were found in patients only between subjective ratings of positive feedback and right insula activation, and a relevant behavioural measure. Evidence suggests potential neural substrates underlying the cognitive representation of social reputation in schizophrenia.


Subject(s)
Schizophrenic Psychology , Social Behavior , Adult , Brain Mapping , Cognition , Feedback, Psychological , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Parietal Lobe/physiopathology , Personality , Reward , Schizophrenia/physiopathology , Young Adult
12.
Annu Int Conf IEEE Eng Med Biol Soc ; 2016: 5833-5836, 2016 Aug.
Article in English | MEDLINE | ID: mdl-28269581

ABSTRACT

Stroke is one of the leading causes of disability worldwide. Consequently, many stroke survivors exhibit difficulties undergoing voluntary movement in their affected upper limb, compromising their functional performance and level of independence. To minimize the negative impact of stroke disabilities, exercises are recognized as a key element in post-stroke rehabilitation. In order to provide the practice of exercises in a uniform and controlled manner as well as increasing the efficiency of therapists' interventions, robotic training has been found, and continues to prove itself, as an innovative intervention for post-stroke rehabilitation. However, the complexity as well as the limited degrees of freedom and workspace of currently commercially available robots can limit their use in clinical settings. Up to now, user-friendly robots covering a sufficiently large workspace for training of the upper limb in its full range of motion are lacking. This paper presents the design and implementation of ERA, an upper-limb 3-DOF force-controlled exerciser robot, which presents a workspace covering the entire range of motion of the upper limb. The ERA robot provides 3D reaching movements in a haptic virtual environment. A description of the hardware and software components of the ERA robot is also presented along with a demonstration of its capabilities in one of the three operational modes that were developed.


Subject(s)
Exercise Therapy/instrumentation , Robotics/instrumentation , Stroke Rehabilitation/instrumentation , Stroke/physiopathology , Upper Extremity/physiopathology , Exercise Therapy/methods , Humans , Movement , Range of Motion, Articular , Robotics/methods , Stroke Rehabilitation/methods
13.
Neurocase ; 21(1): 16-22, 2015 Feb.
Article in English | MEDLINE | ID: mdl-24313336

ABSTRACT

We report the effects of a 4-week trial of deep transcranial magnetic stimulation (DTMS) on depressive and anxious symptoms and brain activity in a patient (Mrs A) with treatment-resistant depression (TRD). The protocol involved a pre- and a post-functional magnetic resonance imaging (fMRI) scan during which Mrs A had to perform a working memory task (i.e., n-back). Her baseline score on the 21-item Hamilton Depression Rating Scale (HAM-D21) was 24, indicating severe depressive symptoms. Immediately after 4 weeks of daily DTMS treatment applied over the left dorsolateral prefrontal cortex (DLPFC), her HAM-D21 score decreased to 13 (a 46% reduction), and 1 month later, it was 12 (a 50% reduction). Moreover, Mrs A's accuracy scores on the n-back task (i.e., 2-back condition) improved from 79% (baseline) to 96% (after DTMS treatment). At the neural level, Mrs A showed significantly increased brain activity in the working memory network (e.g., DLPFC, parietal cortex) during the execution of the 2-back condition after DTMS treatment compared to baseline.


Subject(s)
Brain/physiopathology , Depressive Disorder, Treatment-Resistant/physiopathology , Depressive Disorder, Treatment-Resistant/therapy , Transcranial Magnetic Stimulation , Brain Mapping , Female , Humans , Magnetic Resonance Imaging , Memory, Short-Term/physiology , Middle Aged , Prefrontal Cortex/physiopathology , Severity of Illness Index , Treatment Outcome
14.
J Psychiatry Neurosci ; 39(2): 97-109, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24119792

ABSTRACT

BACKGROUND: Social dysfunction is a hallmark characteristic of schizophrenia. Part of it may stem from an inability to efficiently encode social information into memory and retrieve it later. This study focused on whether patients with schizophrenia show a memory boost for socially relevant information and engage the same neural network as controls when processing social stimuli that were previously encoded into memory. METHODS: Patients with schizophrenia and healthy controls performed a social and nonsocial picture recognition memory task while being scanned. We calculated memory performance using d'. Our main analysis focused on brain activity associated with recognition memory of social and nonsocial pictures. RESULTS: Our study included 28 patients with schizophrenia and 26 controls. Healthy controls demonstrated a memory boost for socially relevant information. In contrast, patients with schizophrenia failed to show enhanced recognition sensitivity for social pictures. At the neural level, patients did not engage the dorsomedial prefrontal cortex (DMPFC) as much as controls while recognizing social pictures. LIMITATIONS: Our study did not include direct measures of self-referential processing. All but 3 patients were taking antipsychotic medications, which may have altered both the behavioural performance during the picture recognition memory task and brain activity. CONCLUSION: Impaired social memory in patients with schizophrenia may be associated with altered DMPFC activity. A reduction of DMPFC activity may reflect less involvement of self-referential processes during memory retrieval. Our functional MRI results contribute to a better mapping of the neural disturbances associated with social memory impairment in patients with schizophrenia and may facilitate the development of innovative treatments, such as transcranial magnetic stimulation.


Subject(s)
Brain/physiopathology , Pattern Recognition, Visual/physiology , Recognition, Psychology/physiology , Schizophrenia/physiopathology , Schizophrenic Psychology , Social Behavior , Adult , Antipsychotic Agents/therapeutic use , Brain Mapping , Female , Humans , Magnetic Resonance Imaging , Male , Neural Pathways/physiopathology , Neuropsychological Tests , Prefrontal Cortex/physiopathology , Schizophrenia/drug therapy
15.
Schizophr Res ; 152(1): 124-9, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24275585

ABSTRACT

BACKGROUND: Single nucleotide polymorphisms in TCF4 gene have been consistently associated with schizophrenia in genome wide association studies, including the C allele of rs9960767. However, its exact role in modulating the schizophrenia phenotype is not known. AIMS: To comprehensively investigate the relationship between rs9960767 risk allele (C) of TCF4 and cognitive performance in patients with first episode psychosis (FEP). METHODS: 173 patients with FEP received a comprehensive neurocognitive evaluation and were genotyped for rs9960767. Carriers of the risk allele (CA/CC) were compared to non-carriers (AA) using Multivariate Analysis of Covariance MANCOVA. Ethnicity, negative symptoms and substance abuse were included as covariates. RESULTS: Carriers of the risk allele had a statistically significant lower performance in the cognitive domain of Reasoning/Problem-Solving compared to non-carriers (F1,172=4.4, p=.038). There were no significant genotype effects on the other cognitive domains or general cognition. This effect on the Reasoning/Problem-Solving domain remained significant even when controlling for IQ (F1,172=4.3, p=.039). CONCLUSIONS: rs9960767 (C) of TCF4 appears to be associated with neurocognitive deficits in the Reasoning/Problem-Solving cognitive domain, in patients with FEP. A confirmation of this finding in a larger sample and including other TCF4 polymorphisms will be needed to gain further validity of this result.


Subject(s)
Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/genetics , Cognition Disorders/genetics , Polymorphism, Single Nucleotide/genetics , Psychotic Disorders/complications , Psychotic Disorders/genetics , Transcription Factors/genetics , Adolescent , Adult , Analysis of Variance , Female , Humans , Male , Neuropsychological Tests , Problem Solving/physiology , Psychiatric Status Rating Scales , Retrospective Studies , Transcription Factor 4 , Young Adult
16.
BMC Psychiatry ; 13: 302, 2013 Nov 15.
Article in English | MEDLINE | ID: mdl-24238299

ABSTRACT

BACKGROUND: Research into the neural correlates of bulimia nervosa (BN) psychopathology remains limited. METHODS: In this functional magnetic resonance imaging study, 21 BN patients and 23 healthy controls (HCs) completed two paradigms: (1) processing of visual food stimuli and (2) comparing their own appearance with that of slim women. Participants also rated food craving and anxiety levels. RESULTS: Brain activation patterns in response to food cues did not differ between women with and without BN. However, when evaluating themselves against images of slim women, BN patients engaged the insula more and the fusiform gyrus less, compared to HCs, suggesting increased self-focus among women with BN whilst comparing themselves to a 'slim ideal'. In these BN patients, exposure to food and body image stimuli increased self-reported levels of anxiety, but not craving. CONCLUSIONS: Our findings suggest that women with BN differ from HCs in the way they process body image, but not in the way they process food stimuli.


Subject(s)
Body Image/psychology , Brain/physiopathology , Bulimia Nervosa/physiopathology , Food , Adult , Brain Mapping , Bulimia Nervosa/psychology , Female , Functional Neuroimaging , Humans , Magnetic Resonance Imaging , Photic Stimulation , Self Report , Surveys and Questionnaires
17.
Schizophr Bull ; 39(3): 640-7, 2013 May.
Article in English | MEDLINE | ID: mdl-22532704

ABSTRACT

BACKGROUND: Impaired facial affect recognition is the most consistent social cognitive finding in schizophrenia. Although social situations provide powerful constraints on our perception, little is known about how situational context modulates facial affect recognition in schizophrenia. METHODS: Study 1 was a single-site study with 34 schizophrenia patients and 22 healthy controls. Study 2 was a 2-site study with 68 schizophrenia patients and 28 controls. Both studies administered a Situational Context Facial Affect Recognition Task with 2 conditions: a situational context condition and a no-context condition. For the situational context condition, a briefly shown face was preceded by a sentence describing either a fear- or surprise-inducing event. In the no-context condition, a face was presented without a sentence. For both conditions, subjects rated how fearful or surprised the face appeared on a 9-point Likert scale. RESULTS: For the situational context condition of study 1, both patients and controls rated faces as more afraid when they were paired with fear-inducing sentences and as more surprised when they were paired with surprise-inducing sentences. The degree of modulation was comparable across groups. For the no-context condition, patients rated faces comparably to controls. The findings of study 2 replicated those from study 1. CONCLUSIONS: Despite previous abnormalities in other types of context paradigms, this study found intact situational context processing in schizophrenia, suggesting that patients benefit from situational context when interpreting ambiguous facial expression. This area of relative social cognitive strength in schizophrenia has implications for social cognitive training programs.


Subject(s)
Affect , Cognition Disorders/physiopathology , Facial Expression , Recognition, Psychology , Schizophrenia/physiopathology , Schizophrenic Psychology , Social Perception , Adult , Case-Control Studies , Cognition Disorders/psychology , Emotions , Female , Humans , Male , Middle Aged , Pattern Recognition, Visual , Social Environment
18.
Schizophr Bull ; 39(3): 617-28, 2013 May.
Article in English | MEDLINE | ID: mdl-22451493

ABSTRACT

INTRODUCTION: Empathic deficits in schizophrenia may lead to social dysfunction, but previous studies of schizophrenia have not modeled empathy through paradigms that (1) present participants with naturalistic social stimuli and (2) link brain activity to "accuracy" about inferring other's emotional states. This study addressed this gap by investigating the neural correlates of empathic accuracy (EA) in schizophrenia. METHODS: Fifteen schizophrenia patients and 15 controls were scanned while continuously rating the affective state of another person shown in a series of videos (ie, targets). These ratings were compared with targets' own self-rated affect, and EA was defined as the correlation between participants' ratings and targets' self-ratings. Targets' self-reported emotional expressivity also was measured. We searched for brain regions whose activity tracked parametrically with (1) perceivers' EA and (2) targets' expressivity. RESULTS: Patients showed reduced EA compared with controls. The left precuneus, left middle frontal gyrus, and bilateral thalamus were significantly more correlated with EA in controls compared with patients. High expressivity in targets was associated with better EA in controls but not in patients. High expressivity was associated with increased brain activity in a large set of regions in controls (eg, fusiform gyrus, medial prefrontal cortex) but not in patients. DISCUSSION: These results use a naturalistic performance measure to confirm that schizophrenic patients demonstrate impaired ability to understand others' internal states. They provide novel evidence about a potential mechanism for this impairment: schizophrenic patients failed to capitalize on targets' emotional expressivity and also demonstrate reduced neural sensitivity to targets' affective cues.


Subject(s)
Brain/physiopathology , Empathy/physiology , Schizophrenia/physiopathology , Schizophrenic Psychology , Social Perception , Adult , Case-Control Studies , Female , Frontal Lobe/physiopathology , Functional Neuroimaging , Humans , Interpersonal Relations , Magnetic Resonance Imaging , Male , Middle Aged , Parietal Lobe/physiopathology , Thalamus/physiopathology
19.
Schizophr Res ; 137(1-3): 39-44, 2012 May.
Article in English | MEDLINE | ID: mdl-22436394

ABSTRACT

BACKGROUND: There is evidence of decreased pleasure and deficits in the anticipation of reward in both psychotic illness and drug addiction. Individuals with low anticipatory pleasure may preferentially engage in behaviours associated with immediate reward such as cannabis use. METHOD: Ninety-one psychosis patients and 91 controls without history of psychosis were administered the Temporal Experience of Pleasure Scale (TEPS), a self report which measures anticipatory and consummatory pleasure. Cannabis use diagnosis was assessed using the Structured Clinical Interview for DSM IV (SCID). Subjects reported the frequency of cannabis consumption and time since last use. RESULTS: Patients did not show a significant deficit in anticipatory or consummatory pleasure compared to controls; however, patients with an active cannabis-use disorder tended to have lower consummatory pleasure than controls with active cannabis disorder (p<.05). Patients who continued to use cannabis during treatment of their first episode of psychosis reported significantly lower anticipatory pleasure compared to those who had a lifetime cannabis diagnosis but were able to maintain abstinence (F(1,60)=5.6, p=.021). Frequency of cannabis use was negatively correlated to anticipatory and consummatory pleasure (Pearson R=-.46, -.48 respectively) in 37 patients currently using cannabis but not in 46 cannabis-using controls (partial R=-.04, -.07 respectively). CONCLUSION: Anticipatory pleasure may not be decreased in early psychosis patients. Lower hedonic response may be associated with persistent, heavy cannabis use in patients in the early phase of psychotic disorders.


Subject(s)
Anticipation, Psychological , Marijuana Abuse/psychology , Pleasure , Psychotic Disorders/psychology , Adult , Analysis of Variance , Female , Humans , Male , Marijuana Abuse/epidemiology , Psychiatric Status Rating Scales , Psychotic Disorders/epidemiology , Residence Characteristics , Reward , Self Report , Young Adult
20.
Neuroimage ; 55(3): 1219-26, 2011 Apr 01.
Article in English | MEDLINE | ID: mdl-21194569

ABSTRACT

INTRODUCTION: There is mounting evidence that visual perception abnormalities in schizophrenia are partly explained by a dysfunction of the lateral occipital complex (LO). We previously demonstrated that schizophrenia patients had broader topography and reduced magnitude of activity of LO. However, the functional connectivity of LO with other brain regions during visual perception has not been directly investigated in schizophrenia. MATERIALS AND METHODS: Eighteen patients with schizophrenia and eighteen matched controls performed a backward masking task during functional magnetic resonance imaging (fMRI). Stimulus onset asynchronies were manipulated to change the level of target visibility. To examine connectivity with LO function we conducted psychophysiological interactions (PPI) analyses using: 1) a region of interest (ROI) approach and 2) a whole brain analysis. ROIs were defined based on a contrast of trials on which a target was presented versus null trials in which no stimuli were presented. RESULTS: Eleven ROIs were identified. Both groups showed similar strength of coupling between LO and the 11 ROIs when visibility was not taken into account. Healthy controls showed clear changes in coupling between LO and prefrontal and parietal regions as a function of target visibility (higher coupling with more visible targets). In comparison, patients showed reduced dynamic coupling with LO in the right superior frontal gyrus (significant after correcting for multiple comparisons) and a trend for reduced coupling in the left precuneus and left inferior frontal regions. Whole brain analysis identified additional regions that showed dynamic coupling with LO in healthy controls, but not in patients. DISCUSSION: The increased coupling between LO and higher-level parietal and prefrontal regions during visual awareness in healthy controls likely reflects visual reentrant processing. The lack of modulation of coupling between LO and key prefrontal and parietal regions found in schizophrenia may partly reflect abnormalities in LO tuning. The altered LO coupling may contribute to visual perception abnormalities in schizophrenia.


Subject(s)
Occipital Lobe/physiology , Schizophrenia/physiopathology , Schizophrenic Psychology , Visual Perception/physiology , Adolescent , Adult , Diagnostic and Statistical Manual of Mental Disorders , Education , Excitatory Postsynaptic Potentials , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neural Pathways/physiology , Perceptual Masking , Photic Stimulation , Psychiatric Status Rating Scales , Psychomotor Performance/physiology , Young Adult
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