Search results for "FUNCTIONAL"
showing 10 items of 4822 documents
Neural mechanisms of training an auditory event‐related potential task in a brain–computer interface context
2019
Effective use of brain-computer interfaces (BCIs) typically requires training. Improved understanding of the neural mechanisms underlying BCI training will facilitate optimisation of BCIs. The current study examined the neural mechanisms related to training for electroencephalography (EEG)-based communication with an auditory event-related potential (ERP) BCI. Neural mechanisms of training in 10 healthy volunteers were assessed with functional magnetic resonance imaging (fMRI) during an auditory ERP-based BCI task before (t1) and after (t5) three ERP-BCI training sessions outside the fMRI scanner (t2, t3, and t4). Attended stimuli were contrasted with ignored stimuli in the first-level fMRI…
Changes in Cerebello-motor Connectivity during Procedural Learning by Actual Execution and Observation
2011
Abstract The cerebellum is involved in motor learning of new procedures both during actual execution of a motor task and during observational training. These processes are thought to depend on the activity of a neural network that involves the lateral cerebellum and primary motor cortex (M1). In this study, we used a twin-coil TMS technique to investigate whether execution and observation of a visuomotor procedural learning task is related to modulation of cerebello-motor connectivity. We observed that, at rest, a magnetic conditioning pulse applied over the lateral cerebellum reduced the motor-evoked potentials obtained by stimulating the contralateral M1, indicating activation of a cerebe…
Increased functional connectivity in gambling disorder correlates with behavioural and emotional dysregulation: Evidence of a role for the cerebellum
2020
Gambling disorder (GD) is a psychiatric disease that has been recently classified as a behavioural addiction. So far, a very few studies have investigated the alteration of functional connectivity in GD patients, thus the concrete interplay between relevant function-dependent circuitries in such disease has not been comprehensively assessed. The aim of this research was to investigate resting-state functional connectivity in GD patients, searching for a correlation with GD symptoms severity. GD patients were assessed for gambling behaviour, impulsivity, cognitive distortions, anxiety and depression, in comparison with healthy controls (HC). Afterwards, they were assessed for resting-state f…
The Effects of Hemianopia on Perception of Mutual Gaze
2019
Significance Individuals with left hemianopic field loss (HFL), especially with neglect history, may have greater difficulties than individuals with right HFL in judging the direction of another person's gaze. Purpose Individuals with HFL often show a spatial bias in laboratory-based perceptual tasks. We investigated whether such biases also manifest in a more real-world task, perception of mutual gaze direction, an important, nonverbal communication cue in social interactions. Methods Participants adjusted the eye position of a life-size virtual head on a monitor at a 1-m distance until (1) the eyes appeared to be looking straight at them, or (2) the eyes were perceived to be no longer loo…
Motivational factors modulate left frontoparietal network during cognitive control in cocaine addiction
2020
Cocaine addiction is characterized by alterations in motivational and cognitive processes involved in goal-directed behavior. Recent studies have shown that addictive behaviors can be attributed to alterations in the activity of large functional networks. The aim of this study was to investigate how cocaine addiction affected the left frontoparietal network during goal-directed behavior in a stop-signal task (SST) with reward contingencies by correct task performance. Twenty-eight healthy controls (HC) and 30 abstinent cocaine-dependent patients (ACD) performed SST with monetary reward contingencies while undergoing a functional magnetic resonance imaging scan. The results showed that the l…
Diseño de una nueva prueba para medir la función de sensibilidad al contraste con iPad
2015
[EN] Purpose: To introduce a new application (ClinicCSF) to measure Contrast Sensitivity Function (CSF) with tablet devices, and to compare it against the Functional Acuity Contrast Test (FACT). Methods: A total of 42 subjects were arranged in two groups of 21 individuals. Different versions of the ClinicCSF (.v1 and .v2) were used to measure the CSF of each group with the same iPad and the results were compared with those measured with the FACT. The agreements between ClinicCSF and FACT for spatial frequencies of 3, 6, 12 and 18 cycles per degree (cpd) were represented by Bland---Altman plots. Results: Statistically significant differences in CSF of both groups were found due to the change…
The Functional Role of Large-scale Brain Network Coordination in Placebo-induced Anxiolysis
2018
Abstract Anxiety reduction through mere expectation of anxiolytic treatment effects (placebo anxiolysis) has enormous clinical importance. Recent behavioral and electrophysiological data suggest that placebo anxiolysis involves reduced vigilance and enhanced internalization of attention; however, the underlying neurobiological mechanisms are not yet clear. Given the fundamental function of intrinsic connectivity networks (ICNs) in basic cognitive processes, we investigated ICN activity patterns associated with externally and internally directed mental states under the influence of an anxiolytic placebo medication. Based on recent findings, we specifically analyzed the functional role of the…
Online Self-Help as an Add-On to Inpatient Psychotherapy: Efficacy of a New Blended Treatment Approach.
2017
<b><i>Background:</i></b> Depression is one of the most frequent and costly mental disorders. While there is increasing evidence for the efficacy of online self-help to improve depression or prevent relapse, there is little evidence in blended care settings, especially combined with inpatient face-to-face psychotherapy. Therefore, we evaluated whether an evidence-based online self-help program improves the efficacy of inpatient psychotherapy. <b><i>Methods:</i></b> A total of 229 depressed patients were randomly allocated either to an online self-help program (intervention group [IG]; Deprexis) or an active control group (CG; weekly online inf…
Multichannel functional testing in normal subjects, glaucoma suspects, and glaucoma patients
2012
Purpose.: To evaluate visual function with a novel multichannel functional test named the ATD Multichannel Functional Test. Methods.: This multicenter study had a prospective and cross-sectional design. A total of 186 eyes were included: 42 with glaucoma, 14 glaucoma suspects due to optic nerve characteristics, 25 ocular hypertensives, and 105 normal eyes. All patients performed standard visual fields (Humphrey 24-2) and ATD with eight stimuli configurations: four achromatic (A), two red-green (T), and two blue-yellow (D). To derive main outcome measures, mean sensitivity, mean defect (MD), and pattern standard deviation (PSD) were calculated and compared among groups and types of stimuli w…
Confirmatory factor analysis of the Patient Assessment of Constipation-Symptoms (PAC-SYM) among patients with chronic constipation.
2015
Background and aim: PAC-SYM is widely adopted to asses constipation severity. However, it has been validated in a small sample, few items have been included based on expert opinion and not on empirical grounds, and its factor structure has never been replicated. We aimed at evaluating the psychometric properties of PAC-SYM in patients with chronic constipation. Methods: We enrolled 2,203 outpatients with chronic constipation in two waves. We used wave I sample to test the psychometric properties of the PAC-SYM and wave II sample to cross-validate its factor structure, to assess criterion validity, responsiveness to clinical change, and its minimal clinically important difference. Results: O…