Building perception block by block: a response to Fekete et al

Abstract

Is consciousness a continuous stream, or do percepts occur only at certain moments of time? This age-old question is still under debate. Both positions face difficult problems, which we proposed to overcome with a 2-stage model, where unconscious processing continuously integrates information before a discrete, conscious percept occurs. Recently, Fekete et al. criticized our model. Here, we show that, contrary to their proposal, simple sliding windows cannot explain apparent motion and related phenomena within a continuous framework, and that their supervenience argument only holds true for qualia realists, a philosophical position we do not adopt.

Keywords: consciousness; discrete perception.

Figure 1.

(a) Apparent motion: In apparent motion, two disks are flashed at different positions separated by a blank period (top). We do not perceive two distinct disks but a single moving disk (bottom). Hence, both disks must be integrated before a percept is created. Hence, an integration period is needed spanning at least the duration of the two disks. (b) Sliding windows can explain why we perceive discrete events as continuous, but not the discreteness of perception. In a sliding window account of apparent motion, before the stimulus is presented, a blank screen would be perceived (not shown). Then, the window reaches the first disk, so we would perceive a static disk (left). Next, both disks fall into the integration window, thus activating motion detectors, and we would perceive continuous apparent motion (centre). Finally, only the second disk is in the window and we would perceive a second static disk (right). However, we only perceive one moving disk. Hence, sliding windows can explain why apparent motion appears to be continuous (i.e. discrete events are perceived as continuous) but not why we do not perceive static disks before and after the motion (i.e. perception is discrete).