Scientific Understanding of Consciousness
Blindsight -- The brain has subcortical pathways for visual information as well is the normal pathways through visual cortex. The subcortical pathway through the brainstem and superior colliculus have been retained by evolution as a backup and to provide a rapid response to threatening stimuli. The pathway through the visual cortex is accessible for consciousness via thalamocortical activity. The subcortical pathway through the colliculus is subconscious and not available for consciousness via linkage with thalamocortical activity.
Blindsight -- cortical blindness. Subcortical structures can guide movement even if part of the information underlying the process is not available to consciousness. (Damasio; Feeling of What Happens, 268)
Blindsight -- blindness in part of the visual field as a result of damage to the occipital lobes of the cortex. (Baddeley; Working Memory, 320)
Blindsight -- Active neurons in the cortical system that are apart from awareness activity at the moment can still lead to behavioral changes but without awareness. These neurons are responsible for the large class of phenomena that bypass awareness in normal subjects, such as automatic processes, priming, subliminal perception, learning without awareness, and others. (Koch and Crick; Neuronal Basis, 97)
Three sets of parallel distinctions between: (1) conscious vision and blindsight, (2) declarative and procedural memory, (3) deliberate and habitual actions; -- together with what is known of their correlates in the brain, lie at the foundations of contemporary theories of consciousness. (Zeman; Consciousness, 284)
Our behavior is mostly governed by a cauldron of emotions and motives of which we are largely unconscious. Incarnations of this idea include such phenomena as blindsight, or the elicitation of changes in skin conductance in patients who have no conscious recognition of faces. (Ramachandran; Illusions of Body Image, 29)