ABSTRACT
BACKGROUND: The brain functional correlates of autobiographical recall are well established, but have been little studied in schizophrenia. Additionally, autobiographical memory is one of a small number of cognitive tasks that activates rather than de-activates the default mode network, which has been found to be dysfunctional in this disorder. METHODS: Twenty-seven schizophrenic patients and 30 healthy controls underwent functional magnetic resonance imaging while viewing cue words that evoked autobiographical memories. Control conditions included both non-memory-evoking cues and a low level baseline (cross fixation). RESULTS: Compared to both non-memory evoking cues and low level baseline, autobiographical recall was associated with activation in default mode network regions in the controls including the medial frontal cortex, the posterior cingulate cortex and the hippocampus, as well as other areas. Clusters of de-activation were seen outside the default mode network. There were no activation differences between the schizophrenic patients and the controls, but the patients showed clusters of failure of de-activation in non-default mode network regions. CONCLUSIONS: According to this study, patients with schizophrenia show intact activation of the default mode network and other regions associated with recall of autobiographical memories. The finding of failure of de-activation outside the network suggests that schizophrenia may be associated with a general difficulty in de-activation rather than dysfunction of the default mode network per se.
Subject(s)
Default Mode Network/physiopathology , Memory, Episodic , Schizophrenia/physiopathology , Schizophrenic Psychology , Adult , Aged , Female , Humans , Magnetic Resonance Imaging , Male , Middle AgedABSTRACT
An altered sense of self-awareness and agency has been proposed to underlie symptoms of schizophrenia. In this study, we used the enfacement illusion paradigm - in which perception of another person's face leads to changes in perception of one's own peri-personal space - to examine the brain correlates of the sense of agency and its potential disruption in schizophrenia. Thirty-three schizophrenic patients and 27 healthy controls underwent fMRI scanning during performance of a task designed to elicit the enfacement illusion. Activations were examined using whole-brain analysis and also in an a priori identified region of interest (ROI) in the temporoparietal junction (TPJ), a region that has been described as involved in self/other differentiation and sense of agency. Both groups showed a pattern of cortical activation involving the pre and postcentral cortex, Rolandic operculum, insula, parietal, temporal and occipital cortex bilaterally as well as TPJ (but only right-side in patients). Examination of the TPJ ROI revealed significantly reduced activation on the left in the patients that was associated with poorer insight. The findings suggest brain functional abnormality in schizophrenia related to the formation or maintenance of processes related to self and/or agency. Decreased function in the TPJ may have a role in the impaired insight seen in patients with the disorder.
Subject(s)
Illusions , Schizophrenia , Brain/diagnostic imaging , Humans , Illusions/physiology , Magnetic Resonance Imaging , Parietal Lobe/diagnostic imagingABSTRACT
BACKGROUND: The negative symptoms of schizophrenia have been proposed to reflect prefrontal cortex dysfunction. However, this proposal has not been consistently supported in functional imaging studies, which have also used executive tasks that may not capture key aspects of negative symptoms such as lack of volition. METHOD: Twenty-four DSM-5 schizophrenic patients with high negative symptoms (HNS), 25 with absent negative symptoms (ANS) and 30 healthy controls underwent fMRI during performance of the Computerized Multiple Elements Test (CMET), a task designed to measure poor organization of goal directed behaviour or 'goal neglect'. Negative symptoms were rated using the PANSS and the Clinical Assessment Interview for Negative Symptoms (CAINS). RESULTS: On whole brain analysis, the ANS patients showed no significant clusters of reduced activation compared to the healthy controls. In contrast, the HNS patients showed hypoactivation compared to the healthy controls in the left anterior frontal cortex, the right dorsolateral prefrontal cortex (DLPFC), the anterior insula bilaterally and the bilateral inferior parietal cortex. When compared to the ANS patients, the HNS patients showed reduced activation in the left anterior frontal cortex, the left DLPFC and the left inferior parietal cortex. After controlling for disorganization scores, differences remained in clusters in the left anterior frontal cortex and the bilateral inferior parietal cortex. CONCLUSIONS: This study provides evidence that reduced prefrontal activation, perhaps especially in the left anterior frontal cortex, is a brain functional correlate of negative symptoms in schizophrenia. The simultaneous finding of reduced inferior parietal cortex activation was unexpected, but could reflect this region's involvement in cognitive control, particularly the 'regulative' component of this.
Subject(s)
Schizophrenia , Schizophrenic Psychology , Goals , Humans , Magnetic Resonance Imaging/methods , Prefrontal Cortex/diagnostic imagingABSTRACT
Schizophrenia is a complex psychiatric disorder that displays an outstanding interindividual variability in clinical manifestation and neurobiological substrates. A better characterization and quantification of this heterogeneity could guide the search for both common abnormalities (linked to lower intersubject variability) and the presence of biological subtypes (leading to a greater heterogeneity across subjects). In the current study, we address interindividual variability in functional connectome by means of resting-state fMRI in a large sample of patients with schizophrenia and healthy controls. Among the different metrics of distance/dissimilarity used to assess variability, geodesic distance showed robust results to head motion. The main findings of the current study point to (i) a higher between subject heterogeneity in the functional connectome of patients, (ii) variable levels of heterogeneity throughout the cortex, with greater variability in frontoparietal and default mode networks, and lower variability in the salience network, and (iii) an association of whole-brain variability with levels of clinical symptom severity and with topological properties of brain networks, suggesting that the average functional connectome overrepresents those patients with lower functional integration and with more severe clinical symptoms. Moreover, after performing a graph theoretical analysis of brain networks, we found that patients with more severe clinical symptoms had decreased connectivity at both whole-brain level and within the salience network, and that patients with higher negative symptoms had large-scale functional integration deficits.
Subject(s)
Connectome , Schizophrenia , Brain/diagnostic imaging , Humans , Magnetic Resonance Imaging , Nerve Net , Schizophrenia/diagnostic imagingABSTRACT
BACKGROUND: An alteration in self/other differentiation has been proposed as a basis for several symptoms in schizophrenia, including delusions of reference and social functioning deficits. Dysfunction of the right temporo-parietal junction (TPJ), a region linked with social cognition, has been proposed as the basis of this alteration. However, imaging studies of self- and other-processing in schizophrenia have shown, so far, inconsistent results. METHODS: Patients with schizophrenia and healthy controls underwent fMRI scanning while performing a task with three conditions: self-reflection, other-reflection and semantic processing. RESULTS: Both groups activated similar brain regions for self- and other-reflection compared to semantic processing, including the medial prefrontal cortex, the precuneus and the TPJ. Compared to healthy subjects, patients hyperactivated the left lateral frontal cortex during self- and other-reflection. In other-reflection, compared to self-reflection, patients failed to increase right TPJ activity. CONCLUSIONS: Altered activity in the right TPJ supports a disturbance in self/other differentiation in schizophrenia, which could be linked with psychotic symptoms and affect social functioning in patients. Hyperactivity of the lateral frontal cortex for self- and other-reflection suggests the presence of greater cognitive demand to perform the task in the patient group.
Subject(s)
Brain/physiopathology , Schizophrenia/physiopathology , Schizophrenic Psychology , Adult , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Self Concept , Social Cognition , Theory of Mind/physiology , Young AdultABSTRACT
OBJECTIVES: The profiles of cortical abnormalities in schizophrenia and bipolar disorder, and how far they resemble each other, have only been studied to a limited extent. The aim of this study was to identify and compare the changes in cortical morphology associated with these pathologies. METHODS: A total of 384 subjects, including 128 patients with schizophrenia, 128 patients with bipolar disorder and 127 sex-age-matched healthy subjects, were examined using cortical surface-based morphology. Four cortical structural measures were studied: cortical volume (CV), cortical thickness (CT), surface area (SA) and gyrification index (GI). Group comparisons for each separate cortical measure were conducted. RESULTS: At a threshold of P = 0.05 corrected, both patient groups showed significant widespread CV and CT reductions in similar areas compared to healthy subjects. However, the changes in schizophrenia were more pronounced. While CV decrease in bipolar disorder was exclusively explained by cortical thinning, in schizophrenia it was driven by changes in CT and partially by SA. Reduced GI was only found in schizophrenia. The direct comparison between both disorders showed significant reductions in all measures in patients with schizophrenia. CONCLUSIONS: Cortical volume and cortical thickness deficits are shared between patients with schizophrenia and bipolar disorder, suggesting that both pathologies may be affected by similar environmental and neurodegenerative factors. However, the exclusive alteration in schizophrenia of metrics related to the geometry and curvature of the brain cortical surface (SA, GI) suggests that this group is influenced by additional neurodevelopmental and genetic factors.
Subject(s)
Bipolar Disorder/pathology , Brain Cortical Thickness , Cerebral Cortex/pathology , Schizophrenia/pathology , Adult , Female , Humans , Magnetic Resonance Imaging , Male , Middle AgedABSTRACT
Counterfactual thinking (CFT) is a type of conditional reasoning involving mental representations of alternatives to past factual events that previous preliminary research has suggested to be impaired in schizophrenia. However, despite the potential impact of these deficits on the functional outcome of these patients, studies examining the role of CFT in this disorder are still few in number. The present study aimed to extent previous results by evaluating CFT in the largest sample to date of schizophrenia patients in symptomatic remission and healthy controls. The relationship with symptomatology, illness duration, and sociodemographic characteristics was also explored. Methods: Seventy-eight schizophrenia patients and 84 healthy controls completed a series of tests that examined the generation of counterfactual thoughts, the influence of the "causal order effect," and the ability to counterfactually derive inferences by using de Counterfactual Inference Test. Results: Compared with controls, patients generated fewer counterfactual thoughts when faced with a simulated scenario. This deficit was negatively related to scores on all dimensions of the Positive and Negative Syndrome Scale-PANNS, as well as to longer illness duration. The results also showed that schizophrenia patients deviated significantly from the normative pattern when generating inferences from CFT. Conclusions: These findings reveal CFT impairment to be present in schizophrenia even when patients are in symptomatic remission. However, symptomatology and illness duration may have a negative influence on these patients' ability to generate counterfactual thoughts. The results might support the relevance of targeting CFT in future treatment approaches, although further research is needed to better describe the relationship between CFT and both symptomatology and functional outcome.
ABSTRACT
UNLABELLED: Subtle social cognitive deficits in unaffected relatives of schizophrenia patients have received increasing attention over the last few years, supporting their potential endophenotypic role for this disorder. The current study assessed non-psychotic first-degree relatives' performance on a multidimensional measure of emotional intelligence (EI): the Mayer-Salovey-Caruso Emotional Intelligence Test 2.0 (MSCEIT). Endorsed by the National Institute of Mental Health, the MSCEIT is a valid and reliable instrument for detecting emotion-processing deficits among schizophrenia patients and people high in schizotypy. METHOD: Thirty-seven first-degree relatives, 37 schizophrenia outpatients and 37 healthy controls completed the MSCEIT, which comprises eight subscales aimed to assess the four branches of EI: Identifying, Facilitating, Understanding and Managing Emotions. Potential associations with cognitive function and schizotypy levels, measured with the Schizotypal Personality Questionnaire-Brief, were further evaluated. RESULTS: Relatives had significantly lower MSCEIT total scores than controls and also significantly lower scores on the Identifying emotions branch. Nevertheless, schizophrenia patients still had the poorest global EI performance. The strongest positive correlations were found in relatives and controls with measures of executive function, processing speed and general intelligence. A higher level of schizotypy correlated significantly with lower MSCEIT scores among controls, but not among relatives. CONCLUSIONS: Contrary to expectations in the general population, the current study observed subtle EI impairment in non-psychotic first-degree relatives of schizophrenia patients. These findings support the hypothesis that these EI deficiencies may be potential endophenotypes located between the clinical phenotype and the genetic predisposition for schizophrenia.
Subject(s)
Emotional Intelligence , Family , Schizophrenic Psychology , Adult , Aged , Endophenotypes , Executive Function , Family/psychology , Female , Genetic Testing , Humans , Intelligence , Male , Middle Aged , Schizophrenia/drug therapy , Schizophrenia/genetics , Young AdultABSTRACT
Counterfactual thinking (CFT) is a type of conditional reasoning that enables the generation of mental simulations of alternatives to past factual events. Previous research has found this cognitive feature to be disrupted in schizophrenia (Hooker et al., 2000; Contreras et al., 2016). At the same time, the study of cognitive deficits in unaffected relatives of people with schizophrenia has significantly increased, supporting its potential endophenotypic role in this disorder. Using an exploratory approach, the current study examined CFT for the first time in a sample of non-psychotic first-degree relatives of schizophrenia patients (N = 43), in comparison with schizophrenia patients (N = 54) and healthy controls (N = 44). A series of tests that assessed the "causal order effect" in CFT and the ability to generate counterfactual thoughts and counterfactually derive inferences using the Counterfactual Inference Test was completed. Associations with variables of basic and social cognition, levels of schizotypy and psychotic-like experiences in addition to clinical and socio-demographic characteristics were also explored. Findings showed that first-degree relatives generated a lower number of counterfactual thoughts than controls, and were more adept at counterfactually deriving inferences, specifically in the scenarios related to regret and to judgments of avoidance in an unusual situation. No other significant results were found. These preliminary findings suggest that non-psychotic first-degree relatives of schizophrenia patients show a subtle disruption of global counterfactual thinking compared with what is normally expected in the general population. Due to the potential impact of such deficits, new treatments targeting CFT improvement might be considered in future management strategies.
ABSTRACT
BACKGROUND: Structural pathology in the hippocampus is well-documented in schizophrenia, but brain functional changes have not been consistently found. We used spatial navigation in a virtual reality environment, a task that is known to produce robust hippocampal activation in healthy subjects, to examine task-related activations and de-activations in the disorder. METHODS: Twenty-seven DSM IV schizophrenia patients and 32 healthy controls underwent fMRI while they navigated to a goal through a virtual reality town. Activations and de-activations were examined at the whole brain level and also using a region-of-interest (ROI) in the hippocampus. RESULTS: Spatial navigation was associated with activation in the posterior hippocampus and parahippocampal gyrus plus widespread neocortical areas. The patients showed reduced activation compared to the controls in the left dorsolateral prefrontal cortex (DLPFC) and the left occipital/temporal cortex. No differences in hippocampal activation were seen either at the whole-brain level or in the ROI analysis. The patients showed failure of de-activation affecting some but not all subregions of the default mode network. CONCLUSIONS: Schizophrenia is associated with task-related hypoactivation in the DLPFC during spatial navigation, but not with functional changes in the hippocampus. The failure of de-activation also found adds to evidence for default mode network dysfunction in the disorder.
Subject(s)
Hippocampus/physiopathology , Schizophrenia/physiopathology , Spatial Navigation/physiology , Adult , Brain Mapping , Female , Humans , Magnetic Resonance Imaging , Male , Neuropsychological Tests , Psychiatric Status Rating Scales , User-Computer InterfaceABSTRACT
En la situación actual de crisis económica es fácil que a nivel asistencial se presenten conflictos entre distintos valores hospitalarios, debiendo priorizar unos por encima de otros. Ante esa situación se decide estudiar e investigar los valores a los que San Benito Menni daba mayor prioridad, es decir su jerarquía de valores. Para ello, se constituyó un grupo de reflexión que, a través del estudio de la abundante documentación epistolar referida al padre Menni y su enmarque en las diferencias entre el escenario socioeconómico-cultural de finales del siglo XIX y el actual, propone una metodología de consenso deductiva-inductiva cuya síntesis es una carta consejo del padre Menni dirigida a los problemas y conflictos actuales (AU)
In the current economic crisis, conflicts between different hospital values are presented. Given this situation it was decided to study and investigate the hierarchy of values of San Benito Menni. A think tank that studied the abundant epistolary documentation referred to Father Menni and its historical context and cultural socio-economic scenario (late nineteenth century and early twentyfirst century) was formed. This group uses a methodology of deductive-inductive consensus whose synthesis is a Father Menni letter addressed to current conflicts (AU)