Psychedelics like psilocybin and ketamine have shown great potential in treating psychiatric disorders, often producing long-lasting effects after a single dose, yet their underlying neural mechanisms remain poorly understood. Since one of the most consistent features of the psychedelic experience is the alteration in perception, this study aimed to investigate how acute doses of psychedelics influence perceptual integration. We used a free-response perceptual integration task in mice, alongside brain-wide mapping of drug-responsive populations using activity-dependent gene expression and calcium imaging in the orbitofrontal cortex (OFC). Our results showed that ketamine (30-50 mg/kg) and psilocybin (0.5-3 mg/kg) significantly slowed response times (RT) and improved task accuracy, while a stimulant, cocaine, had no such effect. A generalized linear model with 3 hidden Markov states (GLM-HMM) revealed that the improvement in accuracy under psychedelics was driven by reduced time in biased states, resulting in increased time in the engaged state. Drift diffusion model (DDM) analysis suggested that these behavioral changes were due to an increased decision boundary, allowing for greater accumulation of evidence before making a decision. Whole-brain c-fos immunostaining revealed distinct brain activation patterns induced by both psychedelics, with increased c-fos expression in several overlapping regions, particularly in the OFC---a critical area for decision-making and value representation. Calcium imaging in the OFC further showed that neurons in this region encode both choice and reward during the task. Together, these results support two models of how psychedelics impact perception: first, by reducing prior expectations, allowing sensory input to dominate decisions, and second, by shifting reward-error encoding, raising decision thresholds. Future work will focus on using calcium imaging data during psychedelic administration to refine and differentiate these models, further clarifying the relationship between OFC activity and psychedelic effects on perceptual tasks.