Abstract: Negative symptoms are treatment-refractory characteristics of schizophrenia that have long been associated with poor functional outcome. Because negative symptoms, including motivational deficits, are a critical unmet need in schizophrenia, there are many ongoing efforts to develop new pharmacological and psychosocial interventions for these impairments. Currently, previous research on negative symptoms in schizophrenia, is usually used in clinical assessment questionnaires and interviews, and objective behavioral assessment method is very lack. In recent years, it is gradually forming a trend about observing negative symptoms, researchers begin to use effort-based decision making paradigms to assess negative symptoms in schizophrenia for clinical trials, especially the amotivation. According to these objective methods, combined with questionnaires and interviews, it must come true to objectively assess amotivation in schizophrenia. Starting from effort-based decision making, we introduce several effort-based paradigms, including the Effort Expenditure for Rewards, Balloon Effort, Grip Strength Effort, Deck Choice Effort, and so on. These tasks covered 2 types of effort: physical and cognitive, These tasks assess how much effort a person is willing to exert for a given level of reward. This area has been well-studied with animal models of effort and motivation, and effort-based decision-making tasks have been adapted for use in humans. There are many challenges in applying in assessing negative symptoms: (1)practice effect. It will have an effect on results. (2)When it’s contradictory between clinical interview-based outcome measures and effort-based decision making measures, how we choose? (3) External validity. Precious studies are in experiments, so it will be questioned to apply the effort-based decision making in clinical trials. (4) The criterions of dependent variables. What’s the standard to meet, if we can think this treatment is effective, is not clear. (5) In most studies, researchers propose the problem that antipsychotic drugs or the dose of them may have an effect on results, but nearly all researchers don’t choose to control them, the most important reason is that it’s too hard to control and they don’t find an effective method. (6) The application of the method to the animal body is applied to the humans, it’s a big problem in fact. Besides, we want to look for neurobiological mechanism of negative symptom:(1) the deficits in processing the rewards and motivation. The patients may have problems in learning rewards and the representative values of rewards are different with each other because of economical status. (2)the deficits in computing the expenditure of efforts. Dopamine system plays a crucial role in containing the expenditure of efforts. (3) Frontal lobe ,including anterior cingulate cortex, posterior cingulate and prefrontal cortex ,also has influenced the willing to expend efforts. In conclusion, the review shows the latest studies , then we try to look for the cognitive and neural mechanism about the amotivation, and point out the challenges and prospects in adapting them for clinical trials in schizophrenia.

Key words: effort-based decision making, amotivation, schizophrenia, negative symptoms

摘要： 近年来，国外运用基于努力决策任务，对阴性症状特别是动机缺失进行研究。通过这种客观的方法，与阴性症状量表和访谈相结合，从而实现对患者的合理评估。从基于努力决策任务出发，综述该类任务在精神分裂症患者动机缺失评估中的最新研究及其神经生物学机制，并指出在实际临床应用中可能遇到的挑战和未来的发展方向。

关键词: 基于努力决策任务, 动机缺失, 精神分裂症, 阴性症状