Abstract
Several perceptual phenomena strikingly demonstrate that visible stimuli can fluctuate into and out of awareness; a physically available object will alternate between being perceived and being ‘invisible’ due to motion-induced blindness (MIB; Bonneh, Cooperman and Sagi 2001), the Troxler effect (TE; Troxler, 1804), and perceptual filling-in (PFI; Ramachandran and Gregory, 1991). There are clear differences between these three paradigms, but each produces a similar phenomenology. A common underlying mechanism responsible for the illusory disappearances has been proposed between MIB and PFI (Hsu, Yeh, Kramer, 2004) and PFI and TE (Komatsu, 2006; De Weerd, Smith and Greenberg, 2006), but it remains unknown how they all relate to one another. In the current study, participants (N=69) completed MIB, TE, and PFI paradigms — MIB: a yellow dot was imposed on a rotating grid of blue crosses; TE: a green dot was presented against a static gray background; PFI: a gray dot was presented against background noise. Two measures were calculated for each participant for each paradigm: the number of dot disappearances and the accumulated duration of the disappearances. To control for alterative explanations, eye movements were monitored and thresholds for the detection of motion coherence and changes in motion speed were determined for each participant. Significant correlations were found between the three paradigms for the number (r’s>0.48, p’s>0.001) and duration (r’s>0.34, p’s>0.01) of dot disappearances, and none of the effects were driven by eye movements or differences in motion coherence or speed perception thresholds. Principal component analyses conducted for the number and duration of disappearances revealed a single factor which explained a large proportion of the variance in MIB, TE, and PFI; 67% for the number and 60% for duration of disappearances. The results suggest a single oscillatory mechanism may underlie these diverse perceptual phenomena.
Meeting abstract presented at VSS 2013