You do not currently have permission to view the full text for this document. Please sign in to an account with an active subscription or contact support.
The idea proposed by Crick and Koch that conscious contents are confined to sensory events is attractive, in part because it is easier to study consciousness in the senses than anywhere else. The last 10 years have seen particularly good progress in studies of the visual cortex, where the question of visual consciousness has almost become normal science. This is an exceptional event in this period of scientific evasion of consciousness (and unconsciousness as well), and it bodes well for a better understanding of both of these essential concepts. Francis Crick and Christof Koch have made pioneering contributions to this emerging literature.
According to Crick and Koch, Freud wrote at times of consciousness as “a sense-organ for the perception of psychical qualities” (1900, p. 615). However, the expression “psychical qualities” would seem to extend beyond sensations to other mental states like thoughts, feelings, intuitions, concepts, beliefs, expectations, and intentions. Fifteen years later Freud wrote of this point as an analogy: “to liken the perception of (unconscious contents) by means of consciousness to the perception of the external world by means of sense-organs” (1915, p. 171). It is only in 1923 that he seems to take it literally: “It dawns upon us like a new discovery that only something which has once been a perception can become conscious, and that anything arising from within (apart from feelings) that seeks to become conscious must try to transform itself into external perception” (1923, p. 19). This is essentially Crick and Koch's claim, following Jackendoff. If we extend the notion of perception to events like mental images, inner speech, and somatically referred sensations, which are internally generated perceptlike experiences, it seems as if all of our mental lives can be understood as sensory in some way. It is in fact quite an old idea. Long before Freud, Plato and Aristotle made their claims upon it.
Shortly before 1900 a long and intractable c