Volen National Center for Complex Systems, Brandeis University, Waltham, Massachusetts, United States of America.
Department of Psychology, Brandeis University, Waltham, Massachusetts, United States of America.
PLoS Comput Biol. 2021 Sep 23;17(9):e1009012. doi: 10.1371/journal.pcbi.1009012. eCollection 2021 Sep.
Decisions as to whether to continue with an ongoing activity or to switch to an alternative are a constant in an animal's natural world, and in particular underlie foraging behavior and performance in food preference tests. Stimuli experienced by the animal both impact the choice and are themselves impacted by the choice, in a dynamic back and forth. Here, we present model neural circuits, based on spiking neurons, in which the choice to switch away from ongoing behavior instantiates this back and forth, arising as a state transition in neural activity. We analyze two classes of circuit, which differ in whether state transitions result from a loss of hedonic input from the stimulus (an "entice to stay" model) or from aversive stimulus-input (a "repel to leave" model). In both classes of model, we find that the mean time spent sampling a stimulus decreases with increasing value of the alternative stimulus, a fact that we linked to the inclusion of depressing synapses in our model. The competitive interaction is much greater in "entice to stay" model networks, which has qualitative features of the marginal value theorem, and thereby provides a framework for optimal foraging behavior. We offer suggestions as to how our models could be discriminatively tested through the analysis of electrophysiological and behavioral data.
对于动物来说，决定是继续进行当前活动还是切换到另一个活动是其在自然世界中的常态，特别是在觅食行为和食物偏好测试中的表现。动物所经历的刺激既会影响选择，也会受到选择的影响，这是一个动态的相互作用过程。在这里，我们提出了基于尖峰神经元的模型神经回路，其中，从正在进行的行为中切换的选择体现了这种相互作用，表现为神经活动的状态转换。我们分析了两类电路，它们的区别在于状态转换是源自刺激的愉悦输入的丧失（“诱使停留”模型）还是来自厌恶刺激的输入（“驱逐离开”模型）。在这两类模型中，我们发现，对刺激的采样时间随着替代刺激的价值增加而减少，这一事实与我们在模型中加入抑制性突触有关。“诱使停留”模型网络中的竞争相互作用要强得多，这具有边缘值定理的定性特征，从而为最佳觅食行为提供了一个框架。我们提出了一些建议，即通过分析电生理和行为数据，可以对我们的模型进行有区别的测试。
