Unconscious Detection but Not Resolution of Cognitive Conflicts Occurs and Influences Conscious Control

The boundaries of unconscious processing have long been an intriguing topic. Despite existing research, the necessity of consciousness for effective high-level conflict control remains an open question. This study seeks to address this research gap through two subliminal Stroop priming experiments combined with event-related potential measurements, aiming to clarify the brain dynamics of unconscious cognitive control and its influence on subsequent conscious control. The participants were instructed to perform color-naming tasks for supraliminal Stroop or non-Stroop targets following subliminal Stroop or non-Stroop primes. In Experiment 1, the primes also served as targets, whereas in Experiment 2, they did not. In both experiments, prime-locked analyses revealed Stroop effects on N450 amplitudes but not on slow potential (SP) amplitudes. Furthermore, target-locked analysis revealed conflict adaptation effects on SP amplitudes and reaction times; the Stroop effects were smaller following Stroop primes compared with non-Stroop primes. Overall, these findings demonstrate that early-stage unconscious cognitive conflict detection occurs and affects subsequent conscious cognitive control; however, there is insufficient evidence to support unconscious conflict resolution. Our study provides valuable insights into the limits of unconscious processing and highlights the importance of further investigating the deep neural pathways underlying unconscious cognitive conflict processing.