Neural time-integration underlying higher cognitive function

高级认知功能背后的神经时间整合

• 批准号: 7466490
• 负责人: Alexander C Huk
• 金额: $ 34.42万
• 依托单位: UNIVERSITY OF TEXAS AT AUSTIN
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-01 至 2013-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7466490
• 关键词: Address; Area; Attention; Behavior; Behavioral; Brain; Brain region; Cells; Characteristics; Cognitive; Complex; Decision Making; Delayed Memory; Discrimination; Eye Movements; Goals; Human; Level of Evidence; Link; Location; Maintenance; Measurement; Memory; Monkeys; Motion; Motor; Neurologic; Neurons; Performance; Photic Stimulation; Physiological; Primates; Process; Property; Prosthesis; Public Health; Purpose; Ramp; Range; Reporting; Research; Rewards; Robotics; Role; Saccades; Sampling; Sensorimotor functions; Sensory; Short-Term Memory; Signal Transduction; Stimulus; Testing; Time; Visual; Work; cognitive function; computer framework; design; expectation; lateral intraparietal area; nonhuman primate; oculomotor; oculomotor behavior; relating to nervous system; research study; response; stimulus interval; visual memory; visual stimulus

DESCRIPTION (provided by applicant): The long-term goal of this research is to understand the basic neural computations that transform sensory signals into representations that support cognitive processes and guide subsequent actions. The research proposed here tests how signals flowing through the lateral intraparietal area (LIP) underlie processes of accumulating and remembering sensory evidence for the purposes of guiding eye-movements. We approach this topic by adapting a computational framework derived from previous work using a direction-discrimination paradigm, and extending it to a wider range of behavioral tasks, experimental phenomena, and theoretical approaches. Our primary goal is to test the degree to which the persistent and ramping activity in LIP reflects neural time-integration, and how this computation relates to sensory stimulation, working memory, and oculomotor planning. Our secondary goal is to better integrate the quantitative inferences available from the direction-discrimination paradigm and time-integration hypothesis to other work on oculomotor computations. We have previously demonstrated that neural activity in area LIP reflects the temporal accumulation of noisy sensory evidence during the performance of a motion direction decision- making task. Because LIP activity is driven strongly by the onset of such a visual target, it is necessary to test whether temporal integration in LIP depends on the presence of a visual stimulus within the response field. We will also assess the cognitive role of persistent activity in LIP. If the persistent activity in LIP supports the combination of multiple pieces of evidence acquired at different times, LIP activity during interleaved periods of stimulus viewing and working memory should reflect the time integral of the sensory evidence. We will test this hypothesis by incorporating a blank memory delay period between successive periods of sensory evidence, and evaluating whether activity during the delay period reflects the accumulated and maintained level of evidence. We will further investigate the relationship between LIP activity and cognitive function by performing a similar task in which two stimuli must be compared, instead of combined. In short, we will manipulate sensory, cognitive, and motor variables to assess the degree to which LIP activity appears to support time integration when: (1) visual stimulation of the response field is manipulated; (2) successive periods of accumulation and maintenance of sensory evidence occur; and (3) the specific eye-movement is not known during the formation of a decision. These measurements will also provide several opportunities to appreciate cell-by- cell diversity in sensory, memory, decision, and motor responses. PUBLIC HEALTH RELEVANCE Primate behavior is intelligent, flexible, and complex. These behavioral strengths often derive from the ability of human and nonhuman primates to combine multiple pieces of evidence acquired at different times. A thorough understanding of how the brain performs this "temporal integration" will benefit neurological treatments, as well as inform technical applications involved in the control and design of intelligent prosthetics and robotics.

描述（由申请人提供）：本研究的长期目标是了解将感觉信号转化为支持认知过程并指导后续行动的表征的基本神经计算。这里提出的研究测试了信号如何通过侧顶叶内区（LIP）来积累和记忆感官证据的过程，以指导眼球运动。我们通过使用方向辨别范式来适应从先前工作中衍生的计算框架，并将其扩展到更广泛的行为任务，实验现象和理论方法来解决这个问题。我们的主要目标是测试LIP中持续和加速的活动在多大程度上反映了神经时间整合，以及这种计算如何与感觉刺激、工作记忆和动眼肌计划相关。我们的第二个目标是更好地整合从方向辨别范式和时间积分假设中获得的定量推论到其他关于动眼肌计算的工作中。我们之前已经证明，在执行运动方向决策任务期间，LIP区域的神经活动反映了噪声感觉证据的时间积累。由于LIP的活动受到视觉目标的强烈驱动，因此有必要测试LIP的时间整合是否取决于反应场中视觉刺激的存在。我们还将评估持续性活动在LIP中的认知作用。如果LIP的持续活动支持在不同时间获得的多个证据的组合，那么在刺激观察和工作记忆的交错时期，LIP的活动应该反映感官证据的时间积分。我们将通过在连续的感官证据之间加入空白记忆延迟期来检验这一假设，并评估延迟期的活动是否反映了积累和维持的证据水平。我们将通过执行一个类似的任务来进一步研究LIP活动与认知功能之间的关系，其中两个刺激必须进行比较，而不是组合。简而言之，我们将操纵感觉、认知和运动变量来评估LIP活动在以下情况下支持时间整合的程度：(1)操纵反应场的视觉刺激；(2)感觉证据的积累和维持是连续的；(3)在决策形成过程中，具体的眼球运动是未知的。这些测量也将提供一些机会来欣赏细胞间在感觉、记忆、决策和运动反应方面的多样性。灵长类动物的行为是聪明、灵活和复杂的。这些行为优势通常来自人类和非人类灵长类动物将不同时间获得的多个证据组合在一起的能力。对大脑如何进行这种“时间整合”的透彻理解将有利于神经学治疗，并为智能假肢和机器人控制和设计的技术应用提供信息。