Temporal dynamics of frustration and reactive aggression: a mouse force pressure proxy in the PSAP-FS

Abstract

This report examined how frustration and reactive aggression unfold over time during the Point Subtraction Aggression Paradigm – First Session (PSAP-FS), using continuous mouse force as a proxy for behavioural frustration. Building on prior findings that force increases following provocation, this follow-up study incorporated time as a key variable, analysing how force changes across 16 provocation-aligned segments and interacts with trait aggression and neural indices. Mixed-effects models revealed a non-linear, biphasic trajectory: force increased through mid-task (peaking around the 8th-12th provocations) and declined thereafter. Reactive aggression, trait anger, hostility, and physical aggression predicted steeper force escalation in segment 3, particularly before provocation - highlighting anticipatory frustration as a central mechanism. Neural variables, including β-to-δ ratio and frontal α asymmetry, showed time-specific effects: lower β-to-δ ratios and greater left-frontal asymmetry were associated with higher early-task force. These findings suggest that frustration-driven behaviour is shaped by individual differences and task phase, with aggression-prone individuals displaying heightened anticipatory reactivity. Modelling time improves understanding of how frustration accumulates, peaks, and dissipates under repeated provocation.