The Objectivity of Subjectivity: A Model of the Brain’s Valuation System

<title>Abstract</title> <p> Philosophers like Plato, Hume, Kant, and others have been debating objectivity versus subjectivity for millenia ¹ . Over time, the trivialization of subjectivity took hold, culminating in artists disdaining it during the twentieth century. Here, we show that subjectivity is not arbitrary because the brain adapts its learning mechanisms to fit each person's unique life context. We performed computer simulations of value learning in a computational model ^2,3 of the valuation system of the brain ^4–7 . These simulations began with equations, methods, initial conditions, and parameters described elsewhere ^2,3 , but we varied the latter two to probe the model. The results of the simulations showed that the valuation system implemented a stochastic-learning process with intrinsic propensity for value diversity. This propensity was magnified by the stable fixed points of the system forming a multidimensional surface, thus having multiple possible convergence targets. Furthermore, after the system reached the convergence surface, a stochastic-resonance process ^8,9 pushed the value parameters to different convergence points. Two other forces that boosted value diversity were internal motivations and external social forces. These results are significant because they mean that the value difference between people, that is, their perceived inter-person subjectivity may be evolutionarily designed. Therefore, subjectivity may be objective. </p>