Nearly all viewers know that horror and thriller films might contain startle effects. How, then, can they be surprised by effects they know are coming? To begin with, the mind monitors space (primarily extra-consciously) for the location, identity, and status of nearby objects. Robin Horton asserts a "primary theory" of human cognition that transcends culture and is based, in part, on a continual need to make "two major distinctions . . . between human beings and other objects; and . . . between self and other."⁹ There is an obvious utility to monitoring the flux of proximate objects, of which none are completely stable, predictable, safe. Location constantly evolves relative to a perceiver. Identity can change in the most fundamental ways: the living die; the dead move; the limb becomes a snake, the friend a murderer. The state of objects is in constant flux: the fixed breaks away and falls; the tumbling projectile comes to rest; life rots. Meanwhile, conscious attention is preoccupied with narrow and new concerns. This is where the cognitive uncanny and startle come in. These responses remind the conscious mind to apply itself to what is always potentially more significant: the consideration of immediate space and its ever-changing objects.

This long-evolving mind, of course, is brought to film screenings, and, regardless of what we consciously know about the space before us (whether mimetic or virtual), this mind functions much as it has done for the last million years. While watching a threat scene in a film like Alien, viewers might consciously anticipate the locker opening as a likely startle moment, but their mind remains concerned, at many levels, with all manner of imaginary spatial concerns: Will the locker be empty or contain something? Will the something be dangerous or benign? If dangerous, what will the threat do to the crew members? Comparing affectively charged startle effects with weaker ones exposes how the weaker effects may develop too slowly to surprise competent, adult viewers. Sticking with the example at hand, first-time viewers very likely are surprised by the intensity of the visual and auditory stimulus of the Jonesey startle. The shots preceding the shock cut of Jonesey range from 30 to 5 seconds--the shock cut is only about 1 second. The viewer’s overall sense of a scene’s speed is affected by cutting rate as well as the degree and type of movement of objects within the frame. In her shock cut, Jonesey is literally in a frenzy of motion--her movements, for a first-time viewer, would almost resist coherent cognition, a bit of perceptual overload accentuated by the extremes of the shot scale: we see only the head and forepaws of Jonesey.

In the end, there are two differences between reality- and film-based startles. Although film-based emotional responses are not "quasi" emotions, conscious reason does evaluate emotional response contextually, and startles derived from mimetic space are ultimately judged harmless, with fight and flight behaviors suppressed. The second major difference between reality- and film-based startles is that film-based startles rely on a formalized structure I call the threat scene, where a character threatened by an offscreen threat is suddenly confronted in onscreen space by a visual and/or auditory intrusion. If the staging of such a scene is frightening and its pacing rapid enough, spectators will respond with true startle. A threat scene's formal tone ultimately develops out of a spectator's empathic identification with character and fear of a depicted threat. Pacing refers to the tempo of the threat scene's staging and editing and engages each spectator's ongoing monitoring of space. Failures to fully anticipate significant changes in one's immediate space (location, identity, status of objects) whether real or simulated, result in surprise, or, more radically, in startle.

Why have startle effects become a common feature of the horror and thriller film genres? The why question is more difficult and diffuse than how startles can occur in film spectators. My own conclusion, not at all original, is that startles prove to us, in the very maw of virtual death, how very much alive we are. Much like the genres they are found in, startles engage our primitive psychophysiologies, and, for the moment, mock our mortality. Perhaps, too, in revealing what we do not actively control of our psychology, startle effects reaffirm the animalistic, the atavistic, and the irrational, expressions the horror and thriller genres have long exposed beneath decorum, utopianism, and reason.