Laetitia L. Thompson

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BACKGROUND Chronic exposure to drugs of addiction induces cellular adaptations in orbitofrontal cortex (OFC) and associated limbic-prefrontal pathways that might underlie abuse-related behavior. A propensity to make risky decisions in spite of substantial negative consequences might be mediated by medial OFC dysfunction in substance-dependent individuals(More)
In an earlier study, we developed the Multiple Sclerosis Neuropsychological Screening Questionnaire (MSNQ) to assist in the screening for neuropsychological (NP) impairments. Self-report MSNQ scores correlated significantly with measures of depression, whereas informant-report MSNQ scores correlated with cognitive performance, but not depression. This study(More)
OBJECTIVE Poor decision-making is a hallmark of addiction, whether to substances or activities. Performance on a widely used test of decision-making, the Iowa Gambling Task (IGT), can discriminate controls from persons with ventral medial frontal lesions, substance-dependence, and pathological gambling. Positron emission tomography (PET) studies indicate(More)
OBJECTIVE Adolescent patients' conduct disorder and substance use disorder symptoms are "risky behaviors" with unpredictable rewards and punishments. The authors asked whether such youths also take excessive risks in new situations without prior learning, peer pressure, or intoxication. METHOD Subjects were 20 adolescent patients in a program treating(More)
OBJECTIVE Substance-dependent individuals make poor decisions on the Iowa Gambling Task, a reward-related decision-making task that involves risk and uncertainty. Task performance depends on several factors, including how sensitive individuals are to feedback and how well they learn based on such feedback. A physiological signal that guides decision making(More)
UNLABELLED Boys with serious conduct and substance problems (Antisocial Substance Dependence (ASD)) repeatedly make impulsive and risky decisions in spite of possible negative consequences. Because prefrontal cortex (PFC) is involved in planning behavior in accord with prior rewards and punishments, structural abnormalities in PFC could contribute to a(More)
The four neurological patient groups and the normals from the Wisconsin Card Sorting Test (WCST) standardization sample were used to examine the discriminability of the WCST's indices. Results reveal consistent differentiation of normals from the patient groups on all WCST variables, with classification rates averaging 71% accuracy. However, patient groups(More)
Clinical examination of memory functions often includes the administration of simple free recall tasks, such as the recall of several words following a few minutes. Little is known, however, about the normative parameters or psychometric properties of such procedures, and such techniques have rarely been compared with more comprehensive, well-standardized(More)
OBJECTIVE To determined the prevalence of vitamin C deficiency (plasma vitamin C concentrations less than 11.4 mumol/L) and vitamin C depletion (plasma vitamin C concentrations from 11.4 to less than 28.4 mumol/L) in an outpatient population. SUBJECTS AND METHODS A consecutive sample of patients presenting at a health maintenance organization laboratory(More)
BACKGROUND Individuals with drug addictions report increased willingness to approach rewards. Approach behaviors are thought to involve executive control processes and are more strongly represented in the left compared to right prefrontal cortex. A direct link between approach tendencies and left hemisphere activity has not been shown in the resting brain.(More)