We explore the application of a new theory of Semantic Information to the well-motivated problem of a resource foraging agent. Semantic information is defined as the subset of correlations, measured via the transfer entropy, between agent $A$ and environment $E$ that is necessary for the agent to maintain its viability $V$. Viability, in turn, is endogenously defined as opposed to the use of exogenous quantities like utility functions. In our model, the forager's movements are determined by its ability to measure, via a sensor, the presence of an individual unit of resource, while the viability function is its expected lifetime. Through counterfactual interventions -- scrambling the correlations between agent and environment via noising the sensor -- we demonstrate the presence of a critical value of the noise parameter, $\eta_c$, above which the forager's expected lifetime is dramatically reduced. On the other hand, for $\eta < \eta_c$ there is little-to-no effect on its ability to survive. We refer to this boundary as the semantic threshold, quantifying the subset of agent-environment correlations that the agent actually needs to maintain its desired state of staying alive. Each bit of information affects the agent's ability to persist both above and below the semantic threshold. Modeling the viability curve and its semantic threshold via forager/environment parameters, we show how the correlations are instantiated. Our work provides a useful model for studies of established agents in terms of semantic information. It also shows that such semantic thresholds may prove useful for understanding the role information plays in allowing systems to become autonomous agents.
翻译:我们探讨了一种基于语义信息理论的新方法,将其应用于资源搜集代理的问题。语义信息被定义为代理$A$和环境$E$之间的相关性子集,通过转移熵来衡量,这些相关性对代理的生存能力$V$至关重要。生存能力是内源性定义的,与使用外源性数量如效用函数不同。在我们的模型中,聚集者的移动是由其通过一个传感器测量资源个体的存在,而其生存能力函数是其预期寿命来确定的。通过反事实干预——通过通过传感器加入噪声来混淆代理和环境之间的相关性——我们展示了噪声参数的临界值$\eta_c$的存在,高于这个值,聚集者预期寿命显著降低。另一方面,对于$\eta < \eta_c$,其生存能力几乎没有受到影响。我们将这个边界称为语义阈值,量化了代理实际上需要维持其所需状态——保持生命的相关性子集。每一位信息都在不同的阈值以上或以下影响着代理的持续存在能力。通过模拟代理与环境参数,我们展示了生存函数曲线及其语义阈值如何被实现。我们的工作为研究已确立的代理提供了有用的模型,以语义信息的角度分析代理。它还表明,这样的语义阈值可能有助于理解信息在使系统成为自主代理方面所扮演的角色。