Deliberative Versus Intuitive System Interaction in Moral Decision-Making Under Time Pressure: EEG Theta and Alpha Lateralization as Neural Markers of Dual-Process Engagement

This study investigates EEG theta and alpha power lateralization during moral decision-making under varying time pressure, testing dual-process predictions about System 1 intuitive versus System 2 deliberative engagement in trolley-problem-type moral dilemmas within the context of cognitive neuroscience and moral psychology, an area of growing scientific importance given its implications for dual process neuroscience theory testing, legal and ethical moral judgment research, and time-constrained decision support design. Using 64-channel EEG at 1000 Hz, event-related spectral perturbation (ERSP) for theta (4-8 Hz) and alpha (8-13 Hz) power, frontal theta midline (Fz) as deliberative working memory marker, parietal alpha lateralization as attentional engagement marker, and mixed-effects LMM for time pressure x moral type interaction, we examine frontal theta increase indexing executive/deliberative engagement (ACC and PFC working memory), reduced under time pressure; parietal alpha suppression indexing stimulus-driven intuitive processing enhanced under time pressure; utilitarian decisions requiring deliberation showing higher theta and greater time-pressure cost than deontological intuitive responses in 48 adults (24F/24M, age 20-35, 64-channel EEG) x 240 moral dilemmas per participant (80 per time condition x 3 conditions) = 11,520 total trials; 84% artifact-free trials retained drawn from Midwestern Brain Science Institute EEG lab with sound-attenuated booth, 64-channel Biosemi ActiveTwo system, custom-built dilemma presentation software, and eye-tracking for blink artifact rejection. Results indicate that personal moral dilemmas (high utilitarian = deliberative) show 2.4-fold higher frontal theta under unlimited vs. 1-s condition (p<0.001); time pressure reduces utilitarian responding 28.4% (p<0.001); parietal alpha suppression predicts deontological choices (r=-0.68, p<0.001) (p < 0.001), with 2.4x frontal theta reduction under time pressure; 28.4% fewer utilitarian responses; r=-0.68 alpha-deontological as the primary quantitative benchmark. Concordance between primary and confirmatory measurement approaches exceeded 93%, validating the analytical framework. These findings contribute empirically to cognitive neuroscience and moral psychology and carry actionable implications for the design of programs and policies targeting dual process neuroscience theory testing, legal and ethical moral judgment research, and time-constrained decision support design.