Relation dynamique entre les signaux électromyographiques et le couple produit au coude lors de contractions à angles constants

Ce mémoire utilise une approche basée sur les méthodes d’identification paramétrique afin de représenter la relation entre signaux électromyographiques du biceps et du triceps versus le moment de force au coude variant dynamiquement lors de contractions à angle constant. La performance de deux modèles linéaires, le modèle «Auto Régressive with eXogenous inputs (ARX)» et le modèle «Output Error(OE)», de plusieurs ordres sont comparées. La performance des modèles est évaluée lors de l’utilisation de différents pré-processeurs, basée sur des canaux uniques ou multiples et l’utilisation d’un filtre «adaptive whitening». Le pré-processeur «multiple channels with adaptive whitening» améliore les performances d’identification. Le modèle OE permet une meilleure identification mais est sujet à des problèmes de convergence.This thesis analyzes different parametric System identification (ID) methods to détermine a linear relationship between electromyographic signais from the biceps and the triceps and a dynamically varying torque about the elbow for constant angles contractions. The performance of two different linear models, Auto Régressive with eXogenous inputs (ARX) and Output Error (OE) of different orders are compared. The performance of the models are estimated with different pre-processors, single and multiple, with / without adaptive whitening filter. The multiple channels with adaptive whitening pre-processor increases the performance of the two models tested. The OE model leads to a better identification performance but is subject to convergence problems.Québec Université Laval, Bibliothèque 201

La perception des infirmières oeuvrant en psychiatrie relativement au plan de carrière en milieu clinique

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

L'efficacité de l'exposition et de la restructuration cognitive dans le traitement du trouble panique

Cette thèse de doctorat vise à répondre à deux questions de recherche auprès de personnes souffrant du trouble panique avec agoraphobie. Premièrement, est-ce qu'il y a une différence dans la rapidité avec laquelle l'exposition et la restructuration cognitive produisent des gains significatifs? Deuxièmement, quel est le mécanisme thérapeutique sous-jacent à ces deux stratégies cognitivo-comportementales? Après avoir fait état des modèles théoriques expliquant l'étiologie et le maintien du trouble panique, les résultats de deux études empiriques sont rapportés. L'objectif de la première étude est d'évaluer, auprès des personnes souffrant d'un trouble panique avec agoraphobie, les différences dans la rapidité avec laquelle l'exposition et la restructuration cognitive produisent des changements sur les variables cliniques, comportementales et cognitives. Vingt-huit sujets recevant un diagnostic de trouble panique avec agoraphobie sont assignés aléatoirement à l'une des deux conditions expérimentales suivantes: Exposition ou Restructuration Cognitive. Les sujets sont évalués à quatre reprises, soit: lors du prétraitement, après 5, 10 et 15 (posttraitement) semaines de traitement. La seconde étude vise à démontrer que les changements dans l'intensité des croyances précèdent les changements du niveau d'appréhension d'une attaque de panique. Deux variables sont mesurées quotidiennement, soit: la force de la principale croyance que chaque sujet entretient envers les attaques de panique, et le niveau d'appréhension d'une attaque de panique. Les ANOVAs indiquent la présence d'un effet "Temps" statistiquement significatif et important pour l'ensemble des instruments de mesure. Toutefois, aucun effet d'interaction "Groupe par Temps" n'est significatif. Ces résultats et des analyses de puissance statistique suggèrent que l'exposition et la restructuration cognitive sont à toutes fin pratique d'une rapidité comparable. Un plus grand nombre de sujets s'avère nécessaire pour confirmer ces résultats. Parmi les sujets qui ne ressentent plus aucune attaque de panique à la fin de ces interventions thérapeutiques, des analyses de séries chronologiques multivariées et des tests de causalité permettent de conclure que les changements de croyance précèdent la réduction du niveau d'appréhension d'une attaque de panique pour 75% d'entre eux. Le mécanisme thérapeutique de l'exposition et de la restructuration cognitive s'avère donc similaire: a savoir la modification des croyances.The aim of this doctoral thesis is to answer two research questions among people suffering from panic disorder with agoraphobia. First, is there a difference in the rate of change between exposure and cognitive restructuring? Second, what is the treatment mechanism operating during exposure and cognitive restructuring? After describing the etiological and maintaining model of panic disorder, results of two empirical studies are described. The aim of the first study was to assess the rate of change on clinical, behavioral and cognitive variables during exposure and cognitive restructuring in the treatment of panic disorder with agoraphobia. A total of 28 subjects who received a diagnosis of panic disorder with agoraphobia were randomly assigned to either of two treatment conditions: Exposure orCognitive Restructuring. Subjects were assessed on four occasions: pretreatment, after 5, 10,and 15 (post-treatment) weeks of treatment. The aim of the second study was to demonstrate that changes in beliefs precede changesin apprehension of a panic attack. Two variables were measured: the strength of each subject'smain beliefs toward the consequence of a panic attack, and the level of apprehension of a panic attack. ANOVAs revealed strong and statistically significant Time effect on all measures. However, no Group X Time interaction reached statistical significance. Furthermore, power analyses sugest that any difference that might exist in the rate of improvement between exposure and cognitive restructuring in the treatment of panic disorder with agoraphobia is marginal. More subjects are needed to confirm these results. However, no Group X Time interaction reached statistical significance. Furthermore, power analyses sugest that any difference that might exist in the rate of improvement between exposure and cognitive restructuring in the treatment of panic disorder with agoraphobia is marginal. More subjects are needed to confirm these results. Multivariate time series analysis and causality testing showed that, for 75% of the subjects who were panic-free at post-treatment, changes in beliefs preceded improvement. Thus, it would seem that the modification of beliefs is involved in the therapeutic mechanism of both exposure and cognitive restructuring

Relative efficacy of cognitive-behavioral therapy administered by videoconference for posttraumatic stress disorder : a six-month follow-up

Until recently, only one study was published on cognitive-behavioral therapy (CBT) of posttraumatic stress disorder (PTSD) in individual therapy via videoconference (Germain, Marchand, Bouchard, Drouin, & Guay, 2009); however, it only assessed the posttreatment effect. This study presents the follow-up of Germain et al.’s (2009) study. The main goal was to compare the effectiveness after six months of CBT for PTSD either face-to-face (n = 24) or by videoconference (n = 12). Each participant received CBT for 16 to 25 weeks and completed various questionnaires before and after treatment and at a six-month follow-up. The two treatments had equivalent levels of symptom reduction (Modified PTSD Symptom Scale: η2 .05) and proportion of patients with a clinically significant change in symptoms (42% for face-to-face vs. 38% for videoconferencing, p > .05). Thus, CBT for PTSD via videoconference seems to be a viable alternative when adequate face-to-face treatments are less available

Cognitive Restructuring for the Treatment of Gambling Related Thoughts: a Systematic Review

Cognitive restructuring is the best practice for treating gambling related thoughts, but some therapists do not apply this technique due to a lack of training regarding its application. The increase of skill game players (e.g., poker) entering treatment adds a challenge for therapists because these gamblers present with different thoughts than those of other gamblers usually encountered in treatment (e.g., EGM). This systematic review aims to describe how cognitive restructuring is carried out with gamblers, particularly skill game players, based on the evidence available in empirical studies that include cognitive interventions for gambling. Of the 2607 studies collected, 41 were retained. Results highlighted exposure as the most frequently used technique to facilitate identification of gambling related thoughts (imaginal = 19.5%; in vivo = 12.2% of studies). More than half of the studies (63.4%) clearly reported therapeutic techniques aimed at correcting gamblers’ thoughts, of which 30.8% involved visual support to challenge the thoughts (e.g. node link mapping, ABC log, cue-cards). Of the 41 retained studies, 46.3% included skill game players in their sample. However, 94.7% of these studies did not mention if cognitive restructuring had been adapted for these players. It was also observed that several terms referring to gamblers’ thoughts were used interchangeably (e.g. erroneous, dysfunctional, irrational or inadequate thoughts), although these terms could each refer to specific content. Clinical implications of the results are discussed with regards to the needs of therapists, but also in relation to editing constraints of scientific journals that may limit detailed description of cognitive restructuring procedures