Abstract. A rhesus monkey, Helen, from whom the striate cortex was almost totally removed, was studied intensively over a period of 8 years. During this time she regained an effective, though limited, degree of visually guided behaviour. The evidence suggests that while Helen suffered a permanent loss of `focal vision she retained (initially unexpressed) the capacity for `ambient vision.

Investigations of the function of consciousness in human information processing have focused mainly on two questions: (1) where does consciousness enter into the information processing sequence and (2) how does conscious processing differ from preconscious and unconscious processing. Input analysis is thought to be initially "preconscious," "pre-attentive," fast, involuntary, and automatic. This is followed by "conscious," "focal-attentive" analysis which is relatively slow, voluntary, and flexible. It is thought that simple, familiar stimuli can be identified preconsciously, but conscious processing is needed (...) to identify complex, novel stimuli. Conscious processing has also been thought to be necessary for choice, learning and memory, and the organization of complex, novel responses, particularly those requiring planning, reflection, or creativity. (shrink)

Right now, you are undergoing the conscious experience of reading this text, combined with a shifting background of sensory, emotional, and cognitive coloring. The conscious experience of the reading, together with the accompanying background feel of sensation, emotion, and thought, make up how things subjectively seem to you, how things appear, as best you can tell, from your own unique point of view. Consciousness is at once acutely familiar-it makes up the experienced moments of your waking (and perhaps your dreaming) (...) life. But consciousness also raises deep and interesting philosophical questions, questions about how any mere physical subject could produce such a wonder, and questions about how there could be a seemingly private and isolated spot of personal subjectivity in an objective, impersonal world. Perhaps the challenge of developing a satisfying theoretical understanding of consciousness is beyond us-we've reached the limits of what we can comprehend. Or maybe today's shortcomings are only temporary barriers to an illuminating theory of consciousness, one properly embedding it in our scientific worldview. And possibly we already have the resources for a satisfactory theory from the way we think about things in commonsense terms. This reader provides an entry point for considering these and related theoretical questions surrounding consciousness. This introductory section begins with a brief background survey of contemporary debates on consciousness. It then provides a characterization of the notion of consciousness at issue, and considers why consciousness understood this way might be theoretically problematic. It follows with a survey of some of the major theoretical positions on consciousness, and it closes with a synopsis of the sections of the book. (shrink)