Search results for "e learning"
showing 10 items of 2703 documents
Decoding attentional states for neurofeedback Mindfulness vs. wandering thoughts
2018
Abstract Neurofeedback requires a direct translation of neuronal brain activity to sensory input given to the user or subject. However, decoding certain states, e.g., mindfulness or wandering thoughts, from ongoing brain activity remains an unresolved problem. In this study, we used magnetoencephalography (MEG) to acquire brain activity during mindfulness meditation and thought-inducing tasks mimicking wandering thoughts. We used a novel real-time feature extraction to decode the mindfulness, i.e., to discriminate it from the thought-inducing tasks. The key methodological novelty of our approach is usage of MEG power spectra and functional connectivity of independent components as features …
Clinical obsessions in obsessive–compulsive patients and obsession-relevant intrusive thoughts in non-clinical, depressed and anxious subjects: Where…
2007
Contemporary cognitive models of obsessive-compulsive disorder (OCD) assume that clinical obsessions evolve from some modalities of intrusive thoughts (ITs) that are experienced by the vast majority of the population. These approaches also consider that the differences between "abnormal" obsessions and "normal" ITs rely on quantitative parameters rather than qualitative. The present paper examines the frequency, contents, emotional impact, consequences, cognitive appraisals and control strategies associated with clinical obsessions in a group of 31 OCD patients compared with the obsession-relevant ITs in three control groups: 22 depressed patients, 31 non-obsessive anxious patients, and 30 …
Quantifying changes in EEG complexity induced by photic stimulation.
2009
Summary Objectives: This study aims to characterize EEG complexity, measured as the prediction error resulting from nonlinear prediction, in healthy humans during photic stimulation. Methods: EEGs were recorded from 15 subjects with eyes closed (EC) and eyes open (EO), during the baseline condition and during stroboscopic photic stimulation (PS) at 5, 10, and 15 Hz. The mean squared prediction error (MSPE) resulting from nearest neighbor local linear prediction was taken as complexity index. Complexity maps were generated interpolating the MSPE index over a schematic scalp representation. Results: Statistical analysis revealed that: i) EEG shows good predictability in all conditions and see…
Lexical decision tasks in depressive patients: semantic priming before and after clinical improvement.
2002
SummaryThis study was designed to evaluate the effect of semantic priming with a lexical decision task in 22 depressed patients (DSM-III-R, 1987) and 30 control subjects. These patients were evaluated twice: first when they arrived at the hospital, and secondly, after clinical improvement. Clinical improvement was evaluated using standard depression rating scales. A lexical decision task involving semantic relations (related vs. unrelated, e.g., apple-pear) was used to evaluate the processing of semantic information. The results showed that, for the first evaluation, the depressives presented similar semantic priming to control subjects. When we compared semantic priming in the first and th…
Radiomic Machine Learning Classifiers in Spine Bone Tumors: A Multi-Software, Multi-Scanner Study
2021
Purpose: Spinal lesion differential diagnosis remains challenging even in MRI. Radiomics and machine learning (ML) have proven useful even in absence of a standardized data mining pipeline. We aimed to assess ML diagnostic performance in spinal lesion differential diagnosis, employing radiomic data extracted by different software. Methods: Patients undergoing MRI for a vertebral lesion were retrospectively analyzed (n = 146, 67 males, 79 females; mean age 63 ± 16 years, range 8-89 years) and constituted the train (n = 100) and internal test cohorts (n = 46). Part of the latter had additional prior exams which constituted a multi-scanner, external test cohort (n = 35). Lesions were la…
The Role of Dysfunctional Cognitions in Patients With Chronic Tinnitus
2015
OBJECTIVES The present study investigates the role of dysfunctional cognitions in patients with chronic tinnitus. To explore different dimensions of tinnitus-related thoughts, a 22-item self-report measure, the "Tinnitus Cognitions Scale" (T-Cog), is presented. Furthermore, dysfunctional cognitions are examined as a possible mediator of the relation between tinnitus distress and depression. DESIGN The present study analyzes the cross-sectional data of 373 patients with chronic tinnitus. Parallel analysis and principal axis factoring are used to identify the factor structure of the T-Cog. Assumed mediating effects are tested using the asymptotic and resampling procedure. RESULTS Factor analy…
MRI radiomics-based machine-learning classification of bone chondrosarcoma.
2019
Abstract Purpose To evaluate the diagnostic performance of machine learning for discrimination between low-grade and high-grade cartilaginous bone tumors based on radiomic parameters extracted from unenhanced magnetic resonance imaging (MRI). Methods We retrospectively enrolled 58 patients with histologically-proven low-grade/atypical cartilaginous tumor of the appendicular skeleton (n = 26) or higher-grade chondrosarcoma (n = 32, including 16 appendicular and 16 axial lesions). They were randomly divided into training (n = 42) and test (n = 16) groups for model tuning and testing, respectively. All tumors were manually segmented on T1-weighted and T2-weighted images by drawing bidimensiona…
One-year follow-up of cardiac anxiety syndromes. Outcome and predictors of course.
1987
In a representative sample (n = 31) of patients with panic attacks and a cardiac anxiety syndrome, a prospective follow-up study after a 1-year interval was performed. At the follow-up assessment 33% of the patients were in remission, whereas the majority of patients had an unfavorable course. Avoidance behavior and female sexual status were found to be predictive for an unfavorable course. Within a matched-pair design controlled for age and sex, no difference between panic disorder with and without cardiac anxiety syndrome was observed in any psychosocial or psychopathological outcome variable. This result is an argument against the validity of the subtype cardiac anxiety syndrome.
Local staging of rectal carcinoma and assessment of the circumferential resection margin with high-resolution MRI using an integrated parallel acquis…
2005
Purpose To assess the diagnostic accuracy of integrated parallel acquisition technique (iPAT) in local staging of rectal carcinoma in comparison to conventional high-resolution MRI. Materials and Methods A total of 28 patients with a neoplasm of the rectum and 15 control patients underwent MRI of the pelvis. High-resolution images were acquired conventionally and with iPAT using a modified sensitivity encoding (mSENSE). Image quality, signal-to-noise and contrast-to-noise ratios (SNR, CNR), tumor extent, nodal status, and delineation of the circumferential resection margin (CRM) were compared. In 19 patients with a carcinoma, MR findings were correlated with the histopathological diagnosis.…
Elderly adults delay proprioceptive reweighting during the anticipation of collision avoidance when standing.
2012
The ability to reweight visual and proprioceptive information is critical for maintaining postural stability in a dynamic environment. In this study, we examined whether visual anticipation of collision avoidance (AV) while standing could facilitate the down-weighting of altered proprioception in young and elderly adults. Twelve young (24.91 ± 6.44 years) and 12 elderly (74.8 ± 6.42 years) participants stood upright for 180 s under two task conditions: (a) quiet stance (QS) and (b) standing while anticipating virtual objects to be avoided. In order to disrupt the accuracy of proprioceptive input participants were exposed to bilateral Achilles tendon vibration during the middle 60 s of stand…