Search results for "Probability"
showing 10 items of 3417 documents
Instantaneous transfer entropy for the study of cardio-respiratory dynamics
2015
Measures of transfer entropy have been proposed to quantify the directional coupling and strength between two complex physiological variables. Particular attention has been given to nonlinear interactions within cardiovascular and respiratory dynamics as influenced by the autonomic nervous system. However, standard transfer entropy estimates have shown major limitations in dealing with issues concerning stochastic system modeling, limited observations in time, and the assumption of stationarity of the considered physiological variables. Moreover, standard estimates are unable to track time-varying changes in nonlinear coupling with high resolution in time. Here, we propose a novel definitio…
Instantaneous Transfer Entropy for the Study of Cardiovascular and Cardio-Respiratory Nonstationary Dynamics
2017
Objective: Measures of transfer entropy (TE) quantify the direction and strength of coupling between two complex systems. Standard approaches assume stationarity of the observations, and therefore are unable to track time-varying changes in nonlinear information transfer with high temporal resolution. In this study, we aim to define and validate novel instantaneous measures of TE to provide an improved assessment of complex nonstationary cardiorespiratory interactions. Methods: We here propose a novel instantaneous point-process TE (ipTE) and validate its assessment as applied to cardiovascular and cardiorespiratory dynamics. In particular, heartbeat and respiratory dynamics are characteriz…
Conscious knowledge and changes in performance in sequence learning: Evidence against dissociation.
1992
International audience; Two experiments examined the relation between explicit knowledge and motor performance on the serial reaction time task developed by Nissen and Bullemer (1987). Tests of free recall and recognition of sequence components revealed that reliable explicit knowledge was acquired after an amount of practice that was hardly sufficient to improve mean motor performance. In addition, reaction time improvement was limited to the ending trials of the 3- and 4-trial sequence components that Ss recalled or recognized. These results were replicated in Experiment 3, in which Ss were trained under attentional distraction in the task developed by Cohen, Ivry, and Keele (1990). Overa…
Cognitive Biases and Decision Making in Gambling
2010
Heuristics and cognitive biases can occur in reasoning and decision making. Some of them are very common in gamblers (illusion of control, representativeness, availability, etc.). Structural characteristics and functioning of games of chance favor the appearance of these biases. Two experiments were conducted with nonpathological gamblers. The first experiment was a game of dice with wagers. In the second experiment, the participants played two bingo games. Specific rules of the games favored the appearance of cognitive bias (illusion of control) and heuristics (representativeness and availability) and influence on the bets. Results and implications for gambling are discussed.
The Factorial Structure of the Outcome Questionnaire-45: A Study with an Italian Sample.
2008
In this article, the authors study the factorial structure of the Italian translation of the Outcome Questionnaire 45 (OQ-45) in a sample of college students (n = 522) and psychiatric outpatients (n = 301). The relative goodness of fit of six competing models of the OQ-45 was examined using confirmatory factor analysis (CFA). Specifically, the study examined the relative fit of the most frequently presented models in the literature and three alternative models. Results of the CFA provided support for the four factor bi-level solution, suggesting that the OQ-45 is a multidimensional instrument that contains one general factor and multiple unique subscale factors.
Changes in the probability of firing of motor units following electrical stimulation in human limb muscles
1986
Changes in the probability of motor unit firing was studied in ten different muscles (six muscles in the upper extremity and four muscles in the lower extremity) of eleven healthy human subjects. The responses were elicited by the electrical stimulation of cutaneous or mixed nerves during weak voluntary contraction of the muscle studied, and were recorded by averaging the rectified surface electromyogram. In eight of the ten muscles, well-detectable, short and long latency excitatory phases were observed. The most constant and well-identified excitatory responses were observed in the first interosseus dorsalis muscle in the hand, and in the extensor digitorum brevis muscle in the foot. Thes…
Temporal stability of the implicit association test-anxiety.
2005
The Implicit Association Test-Anxiety (IAT-Anxiety; Egloff & Schmukle, 2002) provides an indirect assessment of anxiety by measuring associations of self (vs. other) with anxiety-related (vs. calmness-related) words. In 3 studies (using 3 independent samples), we examined the temporal stability of the IAT-Anxiety. In Study 1, 65 participants responded twice to the IAT-Anxiety with a time lag of 1 week. The test-retest correlation was .58. In Study 2 (N = 39), we extended the time interval between test and retest to 1 month and this yielded a stability coefficient of .62. In Study 3 (N = 36), we examined the long-term stability (time lag: 1 year) of the IAT-Anxiety and this showed a correlat…
High-Resolution Computed Tomographic Evaluation of Airway Distensibility and the Effects of Lung Inflation on Airway Caliber in Healthy Subjects and …
2001
The effects of a deep inspiration (DI) in individuals with asthma differ from those observed in healthy subjects. It has been postulated that the beneficial effect of lung inflation is mediated by airway stretch. One hypothesis to explain the defects in the function of lung inflation in asthma is that a DI may be unable to stretch the airways. This may result from attenuation of the tethering forces between the airways and the surrounding parenchyma. In the current study, we used high-resolution computed tomography (HRCT) to examine the ability of a DI to distend the airways of subjects with asthma (n = 10) compared with healthy subjects (n = 9) at baseline and after increasing airway tone …
Mania risk is characterized by an aberrant optimistic update bias for positive life events
2017
Abstract Background Early cognitive models of mania posit that a cognitive triad consisting of unrealistically optimistic beliefs about the self, world and future may predispose vulnerable individuals to develop manic symptoms. Hypomanic personality traits (HYP) pose such a vulnerability factor in the etiopathogenesis of mania. Methods To test the cognitive tenet of overly optimistic views of the future, 24 individuals with high-HYP and 24 age- and sex-matched controls (low-HYP) performed a belief update paradigm, during which they estimated their personal chances to experience future positive and negative life events. Afterwards, they were presented with the statistical likelihood of each …
Cardiorespiratory and Neuromuscular Responses to Motocross Riding
2008
The aim of the present study was to examine physiological and neuromuscular responses during motocross riding at individual maximal speed together with the riding-induced changes in maximal isometric force production. Seven A-level (group A) and 5 hobby-class (group H) motocross-riders performed a 30-minute riding test on a motocross track and maximal muscle strength and oxygen uptake (VO2max) tests in a laboratory. During the riding the mean (+/-SD) VO2 reduced in group A from 86 +/- 10% to 69 +/- 6% of the maximum (P < 0.001), whereas in group H the corresponding reduction was from 94 +/- 25% to 82 +/- 20% (P < 0.05). This relative VO2 during the riding correlated with riding speed (r = 0…