“Significantly, when some new set of stimuli hits us, both body and brain know almost instantly that they are new. The change may be no more than a flash of color seen out of the corner of an eye. . . .

The change in stimuli triggers what experimental psychologists call an “orientation response,”. . . a complex, even massive bodily operation. The pupils of the eyes dilate. Photochemical changes occur in the retina. . . . We involuntarily use our muscles to direct our sense organs toward the incoming stimuli—we lean toward the sound, for example, or squint our eyes to see better. Our general muscle tone rises. There are changes in our pattern of brain waves. Our fingers and toes grow cold as the veins and arteries in them constrict. Our palms sweat. blood rushes to the head. Our breathing and heart rate alter.

Under certian circumstances, we may do all of this—and more—in a very obvious fashion, exhibiting what has been called the “startle reaction.” But even when we are unaware of what is going on, these changes take place every time we perceive novelty in our environment.”

—Alvin Toffler, Future Shock, 1970.