Popping Out Versus Filling In

Although the details differ, Clark shares Block’s claim of the existence of awareness/attention-free phenomenal properties (Clark 2006: 9-10). In addition, Clark – again, like Block – attempts to utilize empirical data to bolster said claim. One example utilized by Clark is that of the “popping out” effect revealed by such visual curiosities as the Kanizsa square (Ibid. 12). What follows is an attempt to undermine Clark’s case based upon the notion that what Clark calls a “pop out” effect in the visual processing of the Kanizsa square is actually a “filling in.” Moreover, “filling in” does not show what Clark claims “popping out” does.

Clark’s case, in short, is as follows. Empirical data supports the notion that vision is a serial process resulting from the combination of distinct/modular systems. The detection of features such as “edge level” occur previous to reportable awareness (Ibid. 5). That the lines of a square are reportable in the Kanizsa square where no such lines actually exist, but are nonetheless reportable, is according to Clark an example of pre-awareness phenomenal properties. This “popping out” “indicates a special kind of ‘preattentive’ processing” (Ibid. 3). The ability to report the awareness of the line is an “example of good, clean, traditional talk of phenomenal properties” (Ibid. 13). Thus, if attention is necessarily present along with the occurrence of phenomenal properties, then, based upon the empirical evidence of the visual system, humans ought not be able to report being able to see the lines of the Kanizsa square.

The empirical data, however, does not demonstrate what Clark thinks it does. “Popping out” in such cases as the Kanizsa square demonstrates that the visual system of humans can “fill in” their phenomenally laden awareness without the stimuli in the world that corresponds to the reported experience. In the case of the Kanizsa square, the lines of a square are “filled in” where no such lines exist in the world. One need not look to such visual curiosities as Kanizsa squares to find evidence of “filling in.” During the entire life of an awake human with normal visual functions is the “filling in” present in the form of the filled in blind spot. Humans do not have a phenomenal free zone where the optic nerve connects to the eyeball, and yet phenomenal properties are there to be reported. What Clark calls the “pop out” effect is actually “filling in.” The appearance of the lines of the Kanizsa square lends support to the idea that humans can “fill in” their visual field, i.e., have awareness with phenomenal properties, without external stimuli, and not that humans can have phenomenal properties without awareness.