BACKGROUND: Early diagnosis of schizophrenia could improve the outcome of the illness. Unlike classical between-group comparisons, machine learning can identify subtle disease patterns on a single subject level, which could help realize the potential of MRI in establishing a psychiatric diagnosis. Machine learning has previously been predominantly tested on gray-matter structural or functional MRI data. In this paper we used a machine learning classifier to differentiate patients with a first episode of schizophrenia-spectrum disorder (FES) from healthy controls using diffusion tensor imaging. METHODS: We applied linear support-vector machine (SVM) and traditional tract based spatial statistics between group analyses to brain fractional anisotropy (FA) data from 77 FES and 77 age and sex matched healthy controls. We also evaluated the effects of medication and symptoms on the SVM classification. RESULTS: The SVM distinguished between patients and controls with significant accuracy of 62.34% (p = 0.005). Participants with FES showed widespread FA reductions relative to controls in a large cluster (N = 56,647 voxels, corrected p = 0.002). The white matter regions, which contributed to the correct identification of participants with FES, overlapped with the regions, which showed lower FA in patients relative to controls. There was no association between the classification performance and medication or symptoms. CONCLUSIONS: Our results provide a proof of concept that SVM might help differentiate FES patients early in the course of illness from healthy controls using white-matter fractional anisotropy. As there was no effect of medications or symptoms, the SVM classification seemed to be based on trait rather than state markers and appeared to capture the lower FA in FES participants relative to controls.
- MeSH
- anizotropie MeSH
- bílá hmota patologie MeSH
- časná diagnóza * MeSH
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- mozek patologie MeSH
- schizofrenie diagnostické zobrazování patologie MeSH
- studie případů a kontrol MeSH
- support vector machine * MeSH
- zobrazování difuzních tenzorů MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: The phenomenology of the clinical symptoms indicates that disturbance of the sense of self be a core marker of schizophrenia. AIMS: To compare neural activity related to the self/other-agency judgment in patients with first-episode schizophrenia-spectrum disorders (FES, n = 35) and healthy controls (HC, n = 35). METHOD: A functional magnetic resonance imaging (fMRI) using motor task with temporal distortion of the visual feedback was employed. A task-related functional connectivity was analyzed with the use of independent component analysis (ICA). RESULTS: (1) During self-agency experience, FES showed a deficit in cortical activation in medial frontal gyrus (BA 10) and posterior cingulate gyrus, (BA 31; P < .05, Family-Wise Error [FWE] corrected). (2) Pooled-sample task-related ICA revealed that the self/other-agency judgment was dependent upon anti-correlated default mode and central-executive networks (DMN/CEN) dynamic switching. This antagonistic mechanism was substantially impaired in FES during the task. DISCUSSION: During self-agency experience, FES demonstrate deficit in engagement of cortical midline structures along with substantial attenuation of anti-correlated DMN/CEN activity underlying normal self/other-agency discriminative processes.
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- cingulární gyrus patofyziologie MeSH
- dospělí MeSH
- konektom metody MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- nervová síť patofyziologie MeSH
- percepční poruchy etiologie patofyziologie MeSH
- pohybová aktivita MeSH
- prefrontální mozková kůra patofyziologie MeSH
- psychomotorický výkon MeSH
- schizofrenie komplikace patofyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Early diagnosis of schizophrenia could improve the outcomes and limit the negative effects of untreated illness. Although participants with schizophrenia show aberrant functional connectivity in brain networks, these between-group differences have a limited diagnostic utility. Novel methods of magnetic resonance imaging (MRI) analyses, such as machine learning (ML), may help bring neuroimaging from the bench to the bedside. Here, we used ML to differentiate participants with a first episode of schizophrenia-spectrum disorder (FES) from healthy controls based on resting-state functional connectivity (rsFC). METHOD: We acquired resting-state functional MRI data from 63 patients with FES who were individually matched by age and sex to 63 healthy controls. We applied linear kernel support vector machines (SVM) to rsFC within the default mode network, the salience network and the central executive network. RESULTS: The SVM applied to the rsFC within the salience network distinguished the FES from the control participants with an accuracy of 73.0% (p = 0.001), specificity of 71.4% and sensitivity of 74.6%. The classification accuracy was not significantly affected by medication dose, or by the presence of psychotic symptoms. The functional connectivity within the default mode or the central executive networks did not yield classification accuracies above chance level. CONCLUSIONS: Seed-based functional connectivity maps can be utilized for diagnostic classification, even early in the course of schizophrenia. The classification was probably based on trait rather than state markers, as symptoms or medications were not significantly associated with classification accuracy. Our results support the role of the anterior insula/salience network in the pathophysiology of FES.
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- dospělí MeSH
- konektom metody MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- mladý dospělý MeSH
- mozková kůra diagnostické zobrazování patofyziologie MeSH
- schizofrenie diagnostické zobrazování patofyziologie MeSH
- support vector machine * MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- adaptace psychologická MeSH
- biologická evoluce * MeSH
- deprese * etiologie psychologie terapie MeSH
- depresivní poruchy * etiologie farmakoterapie psychologie terapie MeSH
- lidé MeSH
- psychologická teorie MeSH
- psychoterapie MeSH
- zármutek MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
BACKGROUND: Aberrant amygdala reactivity to affective stimuli represents a candidate factor predisposing patients with bipolar disorder (BD) to relapse, but it is unclear to what extent amygdala reactivity is state-dependent. We evaluated the modulatory influence of mood on amygdala reactivity and functional connectivity in patients with remitted BD and healthy controls. METHODS: Amygdala response to sad versus neutral faces was investigated using fMRI during periods of normal and sad mood induced by autobiographical scripts. We assessed the functional connectivity of the amygdala to characterize the influence of mood state on the network responsible for the amygdala response. RESULTS: We included 20 patients with remitted BD and 20 controls in our study. The sad and normal mood exerted opposite effects on the amygdala response to emotional faces in patients compared with controls (F1,38 = 5.85, p = 0.020). Sad mood amplified the amygdala response to sad facial stimuli in controls but attenuated the amygdala response in patients. The groups differed in functional connectivity between the amygdala and the inferior prefrontal gyrus (p ≤ 0.05, family-wise error-corrected) of ventrolateral prefrontal cortex (vlPFC) corresponding to Brodmann area 47. The sad mood challenge increased connectivity during the period of processing sad faces in patients but decreased connectivity in controls. LIMITATIONS: Limitations to our study included long-term medication use in the patient group and the fact that we mapped only depressive (not manic) reactivity. CONCLUSION: Our results support the role of the amygdala-vlPFC as the system of dysfunctional contextual affective processing in patients with BD. Opposite amygdala reactivity unmasked by the mood challenge paradigm could represent a trait marker of altered mood regulation in patients with BD.
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- amygdala patofyziologie MeSH
- bipolární porucha patofyziologie psychologie MeSH
- dospělí MeSH
- emoce fyziologie MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- mapování mozku MeSH
- nervové dráhy patofyziologie MeSH
- obličej MeSH
- světelná stimulace MeSH
- výraz obličeje MeSH
- zraková percepce fyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Autoři článku představují nejdůležitější závěry rozsáhlé studie Andrewse a Thomsona (2009), která se zaměřuje zkoumání problematiky pozitivního významu deprese pro kongitivní funkce (tzv. ruminační teorie). Prezentují evoluční názory na význam depresivního onemocnění a v neposlední řadě též citují další experimentální práce navazující na původní práci (Andrews a Thomson, 2009). Na základě poznatků z uvedených studií autoři shrnují agrumentaci směřovanou do oblasti psychoterapeutické praxe: 1. v moderní době často potlačujeme depresivní příznaky, aniž bychom „řešili“ problém, který depresi spustil; 2. cílem terapie je mimo jiné také snaha o navrácení zdravé schopnosti prožívat smutek; 3. vhodnou kontrolní osobou v hodnocení úspěšnosti terapeutické intervence (psychoterapeutické nebo psychofarmakologické) není zdravý dobrovolník, ale dobrovolník „zdravě“ truchlící.
The authors report main ideas presented in a detailed study of Andrews and Thomson (2009) which was focused on examination of a positive impact of depression on analyzing complex problems. The authors present underlying evolutionary perspective for understanding depressive disorder. Other experimental papers that follow this line of thoughts are discussed. Based on the findings of presented studies the authors try to summarize the arguments which could be useful for psychoterapeutic practice: 1. nowdays there is a tendency towards supressing the depressive symptoms without trying to find the problem which might bethe cause of depression; 2. the goal of therapy is to restore the ability to experience sorrow; 3. for measuring the effectivity of psychotherapeutic or pharmacological intervention the appropriate control subjectis not the healthy one, but the one able to grieve in a „healthyway“.
Objectives: Cognitive deficit is considered to be a characteristic feature of schizophrenia disorder. A similar cognitive dysfunction was demonstrated in animal models of schizophrenia. However, the poor comparability of methods used to assess cognition in animals and humans could be responsible for low predictive validity of current animal models. In order to assess spatial abilities in schizophrenia and compare our results with the data obtained in animal models, we designed a virtual analog of the Morris water maze (MWM), the virtual Four Goals Navigation (vFGN) task. Methods: Twenty-nine patients after the first psychotic episode with schizophrenia symptoms and a matched group of healthy volunteers performed the vFGN task. They were required to find and remember four hidden goal positions in an enclosed virtual arena. The task consisted of two parts. The Reference memory (RM) session with a stable goal position was designed to test spatial learning. The Delayed-matching-to-place (DMP) session presented a modified working memory protocol designed to test the ability to remember a sequence of three hidden goal positions. Results: Data obtained in the RM session show impaired spatial learning in schizophrenia patients compared to the healthy controls in pointing and navigation accuracy. The DMP session showed impaired spatial memory in schizophrenia during the recall of spatial sequence and a similar deficit in spatial bias in the probe trials. The pointing accuracy and the quadrant preference showed higher sensitivity toward the cognitive deficit than the navigation accuracy. Direct navigation to the goal was affected by sex and age of the tested subjects. The age affected spatial performance only in healthy controls. Conclusions: Despite some limitations of the study, our results correspond well with the previous studies in animal models of schizophrenia and support the decline of spatial cognition in schizophrenia, indicating the usefulness of the vFGN task in comparative research.
- Publikační typ
- časopisecké články MeSH
- MeSH
- kognitivní poruchy diagnóza MeSH
- lidé MeSH
- schizofrenie diagnóza MeSH
- uživatelské rozhraní počítače * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
