In principle, it might be possible to obtain evidence of focal-attentive processing in the absence of awareness of what is being processed... in practice, however, a complete dissociation of consciousness from focal-attentive processing is difficult to achieve.

p. 665; As cited in: Giorgio Marchetti, "Against the view that consciousness and attention are fully dissociable." Attention and consciousness in different senses (2011): 23. - Is human information processing conscious?, 1991