Integrating Decision Elements for Behavioral Switching

成功的动物在日常活动中往往会在付出的努力、承担的风险和获得的收益方面做出有效的决定。相比之下，影响健康的糟糕决定是焦虑、抑郁和多种形式的精神疾病的特征，这些疾病会导致行为障碍。因此，对决策的神经基础的把握对于任何模拟大脑正常和异常行为组织的统一框架来说都是必不可少的。对决策的神经基础至关重要的是对神经系统如何整合感觉、内部状态和学习的描述。通过对简单捕食性海懒(Pleurobranchaea)的行为和神经系统的研究，建立了一个简单的神经网络模型，用于觅食的成本效益决策。在该模型的背景下，喂养运动网络被有效地设想为一个“目标导向的神经网络”，其兴奋状态由感觉、营养状态和学习来调节。这一特性赋予了组织行为表达的成本效益算法的核心计算元素的角色。理论基础和实验计划被用来阐明嗜好刺激特性、饱足状态和食物回避学习是如何通过摄食运动网络影响定向和回避转向的运动网络中的决策的。具体地说，研究的目的是解释在定向和回避转向之间切换的神经基础，这种切换是如何由感觉、食欲和学习决定的，以及回避决定如何可能抑制喂食行为。将用常规的电生理记录方法对经过良好测试的生理制剂进行研究。结果将对理解动物如何做出成功的行为决定具有广泛的综合意义，这些行为决定如何平衡对可用资源和风险的感知以及它们自己的需求，并将为在更复杂的动物中进行类似的基于价值的决策提供一个简单的模型。本科生，包括少数民族成员，都参与了这些实验室研究活动。来自该实验室的研究相关材料，包括视频、照片和软件，在一个专为本科生和外行编写的易访问性网站上传播，以供公众了解海参行为的神经基础。

Successful animals tend to make efficient decisions in their daily activities in terms of effort spent, risk taken and benefit gained. In contrast, poor decisions affecting fitness are characteristic of anxiety, depression and many forms of mental illness that contribute to behavioral dysfunction. A grasp of the neural bases of decision is therefore essential to any unifying framework that models the organization of normal and abnormal behavior by the brain. Critical to the neural bases of decision is a description of how the nervous system integrates sensation, internal state and learning. A simple neural network model has been derived for cost-benefit decision-making in foraging from studies of behavior and nervous system in the simple predatory sea-slug, Pleurobranchaea. Within the context of the model, the feeding motor network is usefully conceived as a "goal-directed neural network" whose state of excitation is regulated by sensation, nutritional state and learning. This quality confers a role as a central, computational element for the cost-benefit algorithm that organizes expression of behavior. Rationale and experimental plans are outlined to elucidate how appetant stimulus properties, satiated state and food-avoidance learning act through the feeding motor network to influence decision in the motor network mediating both orienting and avoidance turns. Specifically, investigations will be aimed at explaining the neural bases for switching between orienting and avoidance turns, how this switch is determined by sensation, appetite and learning, and how avoidance decision may suppress feeding behavior. Studies will be carried out with conventional electrophysiological recording methods on well-tested physiological preparations. Results will have broad integrative significance to understanding how animals make successful behavioral decisions that balance perception of available resources and risk against their own needs, and will provide a simple model for approaching the neural circuitry for similar value-based decision-making in more complex animals. Undergraduate students, including minority members, are involved in these laboratory research activities. Research related materials from this lab, including videos, photographs and software, are disseminated for public information on the neural basis bases of behavior in sea slugs on a website written for accessibility by undergraduates and laypersons.