fMRI Studies of Working Memory and Motivation

工作记忆和动机的功能磁共振成像研究

• 批准号: 7093930
• 负责人: MARK D'ESPOSITO
• 金额: $ 7.6万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7093930
• 关键词: behavior test; bioimaging /biomedical imaging; brain mapping; clinical research; executive function; functional magnetic resonance imaging; human subject; mathematics; motivation; neuroimaging; performance; prefrontal lobe /cortex; psychobiology; reinforcer; short term memory; statistics /biometry; stimulus /response; time resolved data; visual cortex

DESCRIPTION (provided by applicant): This proposal focuses on the way reward and motivation are linked to executive function. Reward representation and working memory are key functions of the prefrontal cortex (RFC), but their interactions are not well understood at the neural systems level. This line of functional MRI experiments will test fundamental assumptions about the way motivation and performance are represented in the brain. All experiments use variations of a working memory task requiring the maintenance of faces or scenes that has been shown to recruit PFC and posterior visual areas (Parahippocampal Place Area and Fusiform Face Area). Further, the task allows for the separation of working memory component processes involved in encoding, maintenance, and response. Experiment 1 will test whether manipulations of reward value recruit separable, or additional PFC regions and whether modulations in posterior visual areas can be altered by higher motivation trials. A second experiment will investigate financial penalty trials to assess the differences that may exist in a non- rewarded motivation manipulation. There are several theoretical reasons that reward and penalty activation may differ in important ways and these have not been previously tested using cognitive working memory paradigms. Analyses will include whole-brain, ROI, and correlational approaches to assess the activation differences based on varying reward motivation in the task. We hypothesize that activation within encoding, maintenance, and response related regions will be modulated by varying degrees of task motivation based on reward and punishment respectively. We will also include a modified task that will allow for superior modeling of the task periods by using partial trial methodology. This will allow us to test for timing differences in activation between PFC and posterior visual regions at different task phases. Overall, this research will clarify the functional organization of working memory and motivation. The generation of knowledge about reward and cognition has great clinical relevance for understanding the motivational properties of addictive stimuli such as substances of abuse and may also provide insight into a wide range of neurological disorders such as closed head injury, stroke and dementia that cause PFC dysfunction.

描述（由申请人提供）：该提案重点关注奖励和动机与执行功能的联系方式。奖励表征和工作记忆是前额皮质（RFC）的关键功能，但它们的相互作用在神经系统层面上还没有得到很好的理解。这一系列功能性核磁共振实验将测试有关动机和表现在大脑中表现方式的基本假设。所有实验都使用工作记忆任务的变体，需要维持面部或场景，这些面部或场景已被证明可以募集前额皮质和后视觉区域（海马旁区域和梭形面部区域）。此外，该任务允许分离涉及编码、维护和响应的工作记忆组件过程。实验 1 将测试奖励值的操纵是否会招募可分离的或额外的 PFC 区域，以及后视觉区域的调节是否可以通过更高的动机试验来改变。第二个实验将调查经济处罚试验，以评估无奖励动机操纵中可能存在的差异。有几个理论上的原因表明奖励和惩罚激活可能在重要方面有所不同，并且这些原因之前尚未使用认知工作记忆范式进行过测试。分析将包括全脑、投资回报率和相关方法，以根据任务中不同的奖励动机来评估激活差异。我们假设编码、维护和响应相关区域内的激活将分别受到基于奖励和惩罚的不同程度的任务动机的调节。我们还将包括一个修改后的任务，该任务将允许通过使用部分试验方法对任务周期进行高级建模。这将使我们能够测试不同任务阶段 PFC 和后视觉区域之间激活的时间差异。总的来说，这项研究将阐明工作记忆和动机的功能组织。关于奖励和认知的知识的产生对于理解成瘾刺激（例如滥用物质）的动机特性具有很大的临床意义，并且还可以深入了解导致 PFC 功能障碍的各种神经系统疾病，例如闭合性脑损伤、中风和痴呆。