Impulsivity and Time Perception
Cannabis UseCannabis smokers having begun prematurely their consumption (before 16 years) present a persistent impulsivity much later after have stopped their consumptions. The literature highlights that the impulsivity promotes the passage towards a compulsive consumption, and the loss of control. To explain this phenomenon, some authors hypothesized that impulsivity would lead the subjects to overestimate the duration of events and to choose immediate rewards than preferred but delayed rewards. This hypothesis questions the role of the temporal anticipation in the impulsive choices. In a first hypothesis, the temporal impulsivity could be an endogenous deficit bound to the reward, and would be responsible for disorders of the temporal anticipation. In this case, the disorders should be observed especially when the subject anticipates a reward. Alternately, a disorder of the temporal anticipation could provoke impulsivity, and in this case, would be present with or without reward. To separate these hypotheses, we propose to test the capacities of temporal anticipation of non-smokers and early smokers of cannabis by means of a behavioral task " Hazard function task ", which allow to measure the capacity of a subject to anticipate the apparition of an event on the basis of a temporal cue. The neuronal correlates will be measured by a recording EEG of the wave ' CNV ' (fix a quota for denial of variation) which reflects the temporal accumulation and the processes of anticipation.
fMRI in Impulsivity
Impulse Control DisordersBorderline Personality DisorderThis study aims to use resting-state and task based functional Magnetic Resonance Imaging (fMRI) as a tool to evaluate trait characteristics of impulsivity in subjects with borderline personality disorder.
Neuroinflammation, Serotonin, Impulsivity and Suicide
Major Depressive EpisodeSuicidal BehaviorSuicide is a major health problem that causes annually a million death worlwide. In the stress-vulnerability model, suicidal behavior (SB) results from the interaction between an individual's predisposition (personality, family history of SB…) and stressful conditions (early life adversity). Studies show that suicide ideations could favour inflammation and that depression is associated with an elevated inflammation. Recent evidences also suggest that inflammatory mediators play a critical role in SB. The aim of the study is to evaluate the inflammatory markers rate on depressed patients with or without personal history of SB. In the second part of the study, the relations between the rates of inflammatory markers and characteristics of SB, impulsivity, psychological pain, childhood abuse and gene expression of 5HT2B receptor will be investigated.
Common Decision Making Deficits in Suicidal Behaviors and Eating Disorders
Anorexia NervosaBulimia Nervosa4 moreThe role of impulsivity and its contribution to suicidal behavior seems intuitively clear. Empirical results have proved the existence of a relationship between the two yet many questions are left unanswered, especially what differentiates suicide ideators from attempters.. Obsessive thinking patterns are thought processes which share a repetitive behavior domain and are exerted by an inner voice. 3 types of obsessive thinking patterns are self destructive thoughts, ruminations and overvalued ideas. Impulsivity and obsessive thinking patterns are presumed to have a common mechanism of behaviors which are resulted from basal ganglia dysregulation and thus effect inhibition. Novel research in the field of decision making could help to learn more about behavioral patterns associated with self harm behavior and suicide. Eating Disorders involve suicidal and self harm behavior, which both feature impulsivity and obsessive thinking patterns. The investigators study proposes a 3-step theoretical model which asserts there is a connection between impulsivity, obsessive thinking and poor decision making, all effecting self harm behavior. Contemporary research has not been able to fully understand the nature of impulsivity and its effect on self harm behavior, including eating disorders symptoms, nor addressed the impact of obsessive thinking patterns on the latter. 100 female participants with Eating Disorders and suicidal behavior will be recruited for the proposed research. Subjects will be given self-report questionnaires and computerized behavioral tasks. A one way ANOVA of two eating disorder subgroups, impulsive and non impulsive, will be conducted, following a hierarchical multiple regression with self harm behavior being the dependent variable.
Emotional Regulation and Impulsivity Among Adolescents With Borderline Personality Disorder
Borderline Personality DisorderAdolescent DevelopmentThis study aims to better understand the behavioral, neurobiological and hormonal underpinnings of stress and reward reactivity of adolescents suffering from borderline personality disorder compared to healthy adolescents by a multimodal approach based on clinical assessments, structural and functional mri and experimental acute stress exposure.
Motivation and Methylphenidate
MotivationApathy1 moreThe purpose of this study is to evaluate the impact of methylphenidate, a mixed dopaminergic and noradrenergic agent, onto the different components of motivation: decision-making, effort allocation and instrumental learning.
Your Health in On Click
College Student DrinkingEating Disorder7 moreA health education program was provided to higher education students aged between 18 and 25 years. Students were recruited either by posters and leaflets on campus, or during their mandatory medical survey at the University Medical Department. The objectives are to assess health behavior risk among college student : e.g eating disorders, binge drinking, electronic cigarettes and also stress, burnout