Yilong Zhang^1,2 (), Sheng He^1,2, Jiedong Zhang^1,2; ¹State Key Laboratory of Cognitive Science and Mental Health, Institution of Biophysics, Chinese Academy of Sciences, Beijing, China, ²University of Chinese Academy of Sciences, Beijing, China

Sensory information can be processed in the human brain without consciousness. But to what extent can subliminal sensory information influence cognitive processes? Inference is one of the high-level cognitive processes relevant to human intelligence. It is unclear whether it could be triggered by subliminal information. In this study, we designed a physical inference scenario based on collision rules to examine whether individuals could predict the physical outcomes when a visual stimulus is under consciousness. Specifically, a ball was falling onto a tilted bar, and the direction of the bar (cue) could be used to predict the direction of bounce. Continuous flash suppression (CFS) was used to mask the cue stimulus, and a discrimination task was used to assess sensitivity to the ball’s subsequent trajectory. Both the behavioral performance and the electroencephalography (EEG) signal of human participants were recorded to investigate whether they could infer the physical outcome even when the cue was invisible. Behavioral results indicated that the invisible cue significantly improved the ability of discriminating the ball trajectory compared to the no-cue condition. Furthermore, task-relevant feature of the ball trajectory could be decoded from the EEG signal before the ball’s actual trajectory, indicating the existence of inference based on the invisible cue. Overall, this study demonstrates that unconscious information can trigger the intuitive physical inference process, with underlying neural mechanisms potentially related to internal forward mental simulation.