This paper investigates the philosophical and neurobiological dimensions of 'possession', defined as the systematic redefinition of a host’s behavioral output by an external agent. While previous studies have focused on the mechanisms of infiltration, this work addresses the problem of reversibility: under what conditions can a possessed agency be restored? Drawing on a multidisciplinary framework, I propose the 'Principle of Plasticity Asymmetry,' arguing that the neural and cognitive architecture of 'breaking free' is fundamentally different from that of 'falling under' influence. The analysis spans biological instances of parasitic manipulation (e.g., Toxoplasma gondii) to human-specific phenomena such as memetic radicalization and algorithmic possession. From a standpoint of neurophilosophy, the paper distinguishes between functional and structural disruptions of agency, exploring how the corruption of reward systems and the forgery of 'trusted-source' signals create a self-reinforcing state of possession. By synthesizing evidence from evolutionary biology and neuroscience, the article concludes that while biological possession often represents a point of no return, cultural and algorithmic forms of possession remain potentially reversible through targeted interventions in cognitive plasticity and environmental constraints. This work contributes to the ongoing debate on the limits of autonomy and the biological foundations of free will."
