Some researchers are concerned that many perceptual theorists tacitly assume a snapshot conception of experience (Noë, 2002) or a video camera theory of vision (Frisby, 1980). Such tacit assumptions are rooted in our phenomenal experience of an enormously high-quality visual world that seems to be delivered to us effortlessly. “You open your eyes and—presto!—you enjoy a richly detailed picture-like experience of the world, one that represents the world in sharp focus, uniform detail and high resolution from the centre out to the periphery” (Noë, 2002, p. 2).
Indeed, our visual experience suggests that perception puts us in direct contact with reality. Perception is transparent; when we attempt to attend to perceptual processing, we miss the processing itself and instead experience the world around us (Gendler & Hawthorne, 2006). Rather than experiencing the world as picture-like (Noë, 2002), it is as if we simply experience the world (Chalmers, 2006; MerleauPonty, 1962). Merleau-Ponty (1962, p. 77) noted that “our perception ends in objects, and the object[,] once constituted, appears as the reason for all the experiences of it which we have had or could have.” Chalmers (2006) asserts that,
in the Garden of Eden, we had unmediated contact with the world. We were directly acquainted with objects in the world and with their properties. Objects were presented to us without causal mediation, and properties were revealed to us in their true intrinsic glory. (Chalmers, 2006, p. 49)
To say that visual processing is transparent is to say that we are only aware of the contents that visual processes deliver. This was a central assumption to the so-called New Look theory of perception. For instance, Bruner (1957, p. 124) presumed that “all perceptual experience is necessarily the end product of a categorization process.” Ecological perception (Gibson, 1979), a theory that stands in strong opposition in almost every respect to the New Look, also agrees that perceptual processes are transparent. “What one becomes aware of by holding still, closing one eye, and observing a frozen scene are not visual sensations but only the surfaces of the world that are viewed now from here” (p. 286, italics original).
That visual processing is transparent is not a position endorsed by all. For instance, eighteenth-century philosopher George Berkeley and nineteenth-century art critic John Ruskin both argued that it was possible to recover the “innocence of the eye” (Gombrich, 1960). According to this view, it is assumed that at birth humans have no concepts, and therefore cannot experience the world in terms of objects or categories; “what we really see is only a medley of colored patches such as Turner paints” (p. 296). Seeing the world of objects requires learning about the required categories. It was assumed that an artist could return to the “innocent eye”: “the painter must clear his mind of all he knows about the object he sees, wipe the slate clean, and make nature write her own story” (p. 297).
Most modern theories of visual perception take the middle ground between the New Look and the innocent eye by proposing that our experience of visual categories is supported by, or composed of, sensed information (Mach, 1959). Mach (1959) proclaimed that,
thus, perceptions, presentations, volitions, and emotions, in short the whole inner and outer world, are put together, in combinations of varying evanescence and permanence, out of a small number of homogeneous elements. Usually, these elements are called sensations. (Mach, 1959, p. 22)
From this perspective, a key issue facing any theory of seeing or visualizing is determining where sensation ends and where perception begins.
Unfortunately, the demarcation between sensation and perception is not easily determined by introspection. Subjective experience can easily lead us to the intentional fallacy in which a property of the content of a mental representation is mistakenly attributed to the representation itself (Pylyshyn, 2003c). We see in the next section that the transparency of visual processing hides from our awareness a controversial set of processes that must cope with tremendously complex information processing problems.