The Role of Dopamine in Reality Memory
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 发起方
- 入组人数
- 39
- 试验地点
- 2
- 主要终点
- Reality-monitoring performance
研究概览
简要总结
Reality-monitoring characterizes the ability to determine whether information was perceived in the environment or only imagined . Impaired reality-monitoring abilities have been associated with hallucinations in patients with schizophrenia and patients with Parkinson's disease.
The investigators hypothesize a link between dopaminergic (DA) transmission and reality-monitoring.
详细描述
This hypothesis is based on several studies in the literature: 1) DA transmission anomalies are observed in both schizophrenia and Parkinson's disease; 2) DA agonists may induce hallucination; 3) DA antagonists reduce hallucinations and improve reality-monitoring abilities in patients with schizophrenia. In addition, also suggesting a link between mesocorticolimbic connectivity, subcortical DA transmission and reality-monitoring, The investigators have shown that fronto-temporal transcranial Direct Current Stimulation (tDCS) leads:
- on the one hand, to modulate reality-monitoring performance in healthy volunteers and patients;
- on the other hand, to induce subcortical DA release. However, to date, no study has yet explored the direct link between DA transmission and reality-monitoring.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Single (Participant)
盲法说明
double dummy, placebo-controlled
入排标准
- 年龄范围
- 18 Years 至 45 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Healthy volunteers who have given their written informed consent
- •Men and women from 18 to 45 years old
- •Normal or corrected vision
- •Being fluent in French or French for native language
- •Being affiliated with health insurance
排除标准
- •Healthy volunteers who have given their written informed consent
- •Men and women from 18 to 45 years old
- •Normal or corrected vision
- •Being fluent in French or French for native language
- •Being affiliated with health insurance
- •Inadmissibility of the subject's consent or refusal
- •Working-memory deficit (as controlled with MMSE score< 23)
- •Any past or current psychiatric or somatic condition(as controlled with the Mini International Neuropsychiatric Interview, MINI)
- •Any past or current neurological condition
- •History of cranio-cerebral trauma, arterial hypotension or hypertension, cardiological or serious medical condition
- •Abnormal potassium dosage (below 3.1 mmol/L or above 4.9 mmol/L)
- •Anormal ECG
- •History of schizophrenia or bipolar disorder in first-degree relatives
- •Alcohol-drinking and caffeine intake at least during 24 hours before each session
- •Drug therapy excepting contraceptives
- •Cardiologic or severe medical conditio
- •Pregnancy(checked with a pregnancy autotest), lactation, or insufficient contraceptive measure (precautionary measure)
- •Consumption of recreational drugs during the last 6 months
- •Known sensitivity to any of the study medication and their excipients
- •Lactose intolerance
- •Porphyria
- •Hepatic insufficiency
研究组 & 干预措施
Dopamine precursor
In the first condition, volunteers will receive a dopamine (DA) precursor (L-dopa, 100mg). L-dopa will be combined with a dose of an Aromatic amino acid decarboxylase inhibitor (Benserazide) 25mg to multiplicate its bioavailability and with a dose of domperidone 10mg (peripheral antagonist of DA) to minimize the risk of side effects.
干预措施: Précurseur de la dopamine (Other)
D2 antagonist
In the second condition, volunteers will receive a D2 antagonist (Sulpiride, 800mg)
干预措施: antagoniste D2 (Other)
PLACEBO
In the third condition, volunteers will receive a placebo (lactose)
干预措施: PLACEBO (Other)
结局指标
主要结局
Reality-monitoring performance
时间窗: One month
Measured with a behavioral task developed, validated and used in investigators lab. During the memory retrieval phase, 48 words will be presented, including the 32 words presented during encoding as well as 16 new words. Subjects will be required to identify whether each word was previously heard, imagined or new. Three words lists will be used and assigned randomly depending on the substance condition (L-dopa, Sulpiride, placebo). Each verbal list will include 16 items with the "imagine hear" encoding condition and 16 items with the "listen" encoding condition. A single measure including two variables of interest will account for the main evaluation criteria: * The average conditional source-identification measure (ACSIM) which represents the overall ability to correctly retrieve the source, conditional on that item was recognized as already presented. * The source misattributions,the number of confusions between heard and imagined events.
次要结局
- Reaction times at the reality-monitoring task and scores of subjective confidence rating for reality-monitoring responses(One month)
- Other cognitive tasks(One month)