Respiration-entrained neural activities have been theorized to play an integral part in perceptual processing. Given that breathing is a flexible process and can be partly controlled voluntarily, these distinct features may provide a window into how brain-respiration interactions coordinate visual perception. In this study, participants’ breathing was paced at a normal or slow rate while concurrently discriminating fearful from neutral expressions presented during ongoing inspiration or expiration. Behavioral results showed that slow-paced breathing relative to normal-paced breathing decreased d prime values during expiration but not inspiration. The corroborating neural dynamics, as detected by magnetoencephalography, showed distinct response-related correlates between the paces. In particular, slow-paced expiration diminished peristimulus response-related power elicited during the normal-paced condition, although for both breathing paces in the later poststimulus stage, response-related power propagated from the alpha band to a broader frequency band and from the occipital to distributed but somewhat overlapped regions. Echoing the behavioral results, slow-paced expiration modulated the sensory representations between fearful and neutral expressions within the corresponding distinct response-related correlates. This pace-dependent effect was mediated across a hierarchy of spatial-temporal scales. First, slow-paced expiration primarily decreased prestimulus theta phase coherence due to reduced respiration-brain phase synchronization. As a result of this cortical adjustment, the coupling between prestimulus phase and response-related power activities was enhanced, which might ultimately lead to decreased perceptual sensitivity. Our research thus elucidates how breathing pace, through voluntary control, may interact with the brain and, in turn, constitute a top-down source that impinges on visual perception.