Sunday Book-Thought 64

All media are a reconstruction, a model of some biological capability speeded up beyond the human ability to perform: the wheel is an extension of the foot, the book is an extension of the eye, clothing an extension of the skin, and electronic circuitry is an extension of the central nervous system. Each medium is brought to the pinnacle of vortical strength, with the power to mesmerize us. When media act together they can so change our consciousness as to create whole new universes of psychic meaning.
Marshall McLuhan and Bruce R. Powers, The Global Village: Transformations in World Life and Media in the 21st Century (Oxford: Oxford University Press, 1989), p. 87.

Sunday Book-Thought 59

All Western ‘scientific’ models of communication are, like the Shannon-Weaver model, linear, logical, and sequential in accordance with the pattern of efficient causality.
These are all in the figure-minus-ground mode of the left hemisphere, and in contrast do not relate to the effects of simultaneity and discontinuity and resonance that typify experience in an electronic culture. For use in the electric age, a right-hemisphere model of communication is necessary, both because our culture has nearly completed the process of shifting its cognitive modes from the left to the right hemisphere, and because the electronic media themselves are right-hemisphere in their patterns and operation. The problem is to discover such a model that yet is congenial to our culture with its residuum of left-hemisphere tradition. Such a model would have to take into account the apposition of both figure and ground instead of concentrating solely on an abstract sequence or movement isolated from any ground.
Marshall McLuhan and Eric McLuhan, Laws of Media: The New Science (Toronto: University of Toronto Press, 1988), pp. 90-91.