A distinction is introduced between cognitive processes, which never reach consciousness, and results of cognitive processes (representations), which may become conscious. Following brain damage, representations and consciousness may break down. This phenomenon is termed dissociation between preserved implicit (non-conscious) knowledge and impaired explicit (conscious) knowledge. Examples of the implicit/explicit dissociation are provided based on neuropsychological deficits such as cortical blindness, prosopoagnosia, neglect and amnesia. It is argued that there is no unitary area in the brain on which conscious experience depends. It is proposed that the contents of consciousness depend on two factors: a) the activity of certain specific cortical areas, and b) attention. That is, the result of a given cognitive process can reach consciousness only if it occurs with the mediation of attention and involves a cortical area endowed with the "capability of consciousness".