Functional Neuroimaging of Strategic Retrieval Processes

描述(申请人提供)：情节记忆关键地依赖于生成检索计划、检索探测的精心处理、干扰的解决以及关于决策标准的记忆充分性的监测。虽然前额叶皮质(PFC)是这些机制的首选候选区域，但这些机制的区域和半球定位尚不清楚。使用成分-过程模型，我们将：(1)确定Left PFC是否关键地参与了情节提取计划的制定。最近对比背景和项目记忆的研究一致地确认了左PFC，并表明活动不依赖于成功，这表明提取背景信息的意图是关键的。在这里，我们打算分离线索/问题和探测相关活动，并确定这些区域在基于上下文的检索需求期间是否对非言语探测做出反应。(2)基于决策理论对记忆决策标准进行操作。通过操纵决策标准的数量、位置和质量，我们将隔离对将决策规则实施到内存内容至关重要的PFC区域。(3)研究情景提取过程中大脑半球的不对称性。最近的证据表明，PFC的半球不对称(特别是背侧和极地)，左侧区域与上下文特定的来源归因相关，而相应的右侧PFC区域在项目新近或频率的判断过程中显示出相对增加，这可能是基于全局熟悉度评估。通过直接对比受试者内匹配材料的新近程度、频率和背景提取，我们将测试两个大脑半球是否参与了记忆提取的根本不同方面，超越了先前的概念，如“努力”或“困难”。健康老龄化和神经疾病(如阿尔茨海默氏症、轻度认知障碍、创伤性脑损伤)期间的神经学变化严重影响记忆能力。然而，由于调控记忆表达的控制或决策过程知之甚少，行为障碍通常是由于代表或存储记忆证据的系统、负责对内容施加决策的系统或两者的某种组合受到损害而造成的。因此，确定PFC区域通常如何调节将记忆内容转化为决策或动作的方式，对于理解上述人群的记忆性能下降至关重要。

DESCRIPTION (provided by applicant): Episodic remembering critically relies on the generation retrieval plans, the elaborative processing of retrieval probes, the resolution of interference, and the monitoring of the sufficiency of memory with respect to decision criteria. Although prefrontal cortex (PFC) is the favored candidate for these mechanisms, regional and hemispheric localization for these mechanisms is unclear. Using a component-process model we will: (1) Determine whether left PFC is critically involved in formulating episodic retrieval plans. Recent research contrasting context and item memory have consistently identified left PFC and indicated that activity is not dependent on success, suggesting that it is the intent to retrieve contextual information that is critical. Here we intend to separate cue/question and probe dependent activity and determine whether these regions respond to non-verbalizable probes during contextually based retrieval demands. (2) Conduct Decision Theory based manipulations of memory decision criteria. By manipulating the number, location, and quality of decision criteria we will isolate PFC regions critical for implementing decision rules to memory content. (3) Investigate hemispheric asymmetries during episodic retrieval. Recent evidence suggests hemispheric asymmetries in PFC (particularly dorsal and polar) with left regions associated with contextually specific source attribution, and homologous right PFC regions showing relative increases during judgments of item recency or frequency, which are potentially based on global familiarity assessment. By directly contrasting recency, frequency, and context retrieval for matched materials within subjects, we will test whether the hemispheres are involved in fundamentally different aspects of memory retrieval, advancing beyond earlier constructs such as "effort" or "difficulty". Neurological changes during healthy aging and neurological disorders (e.g., Alzheimer's Dementia, Mild Cognitive Impairment, Traumatic Brain Injury) severely impact memory performance. However, because the control or decision processes regulating memory expression are poorly understood, behavioral impairments could often result from damage to systems that represent or store memory evidence, systems responsible for imposing decisions upon that content, or some combination of the 2. Determining how PFC regions normally regulate the translation of memory content into decisions or actions is therefore critical in understanding the memory performance decline in the above populations.