Associative Learning and Adverse Childhood Experiences: A Multi-System Protocol

Adverse childhood experiences (ACEs) are established transdiagnostic risk factors for adult anxiety and depression, yet the neurocognitive mechanisms linking early adversity to symptoms remain unclear within a unified framework. This protocol presents an integrated, multi-system experimental battery that captures threat discrimination, safety learning, and reward sensitivity within a single laboratory session. Thirty-eight healthy adults completed three behavioral paradigms - Pavlovian-to-operant fear conditioning with avoidance (Experiment 1), fear acquisition-extinction-reacquisition with social stimuli (Experiment 2), and probabilistic reward learning (Experiment 3) - alongside validated self-reports of childhood adversity (CTQ-SF), benevolent childhood experiences (BCE), depression (PHQ-9), and anxiety (GAD-7, STAI). Multi-channel data were collected concurrently: skin conductance response (SCR) as a physiological index of autonomic arousal, button-press avoidance and probabilistic choices as behavioral indices, and phase-by-phase subjective ratings of expectancy, threat, and relief. Each paradigm produced its canonical effect: Pavlovian discrimination on SCR (p = 0.009, ηp² = 0.12), expectancy (p < 0.001, ηp² = 0.58), and threat ratings (p < 0.001, ηp² = 0.35); operant relief discriminating avoidable from unavoidable threat (p < 0.001, d = 0.86); differential autonomic responding present at acquisition but not extinction in Experiment 2 (acquisition p = 0.008; extinction p = 0.168) coexisting with persistent declarative knowledge of the contingency (p < 0.001, d = 3.08); and above-chance probabilistic reward learning in Experiment 3 (M = 73%, p < 0.001, d = 1.97). The multi-system design revealed dissociations that a single channel would have missed, most notably attenuated autonomic responding alongside persistent subjective threat. Per-participant indices derived from the protocol were sensitive to individual differences in childhood experience, with illustrative moderation analyses reported in the supplementary material. The protocol provides a portable, scalable framework for indexing how early adversity recalibrates threat and reward processing in adulthood.