There is even redundancy built into perceptual pathways themselves, such as the superior and inferior colliculi (in the mid-brain pontine area), that carry visual and auditory information, respectively, to sensory association areas and NOT to the primary visual or auditory cortex.
(I believe that there is an olfactory analog in mammals called the Jacobsen’s Organ which is underdeveloped in humans compared to other mammalian taxa; see great book on it by Lyall Watson).
Implication is that much of what we consciously code in immediate perception and memory is emergent from a lot of cognitive filtering from different brain areas, which is also subject to regulation by affective and attentional states; hence reactions to stimuli that are not consciously perceived in the visual field though unconsciously encoded.