The effects of eccentricity and retinal illuminance on the illusory motion seen in a stationary luminance gradient

Abstract

Kitaoka recently reported a novel illusion named the Rotating Snakes [Kitaoka, A., & Ashida, H. (2003). Phenomenal characteristics of the peripheral drift illusion. Vision, 15, 261-262], in which a stationary pattern appears to rotate constantly. In the first experiment, we attempted to quantify the anecdote that this illusion is better perceived in the periphery. The stimulus was a ring composed of stepwise luminance patterns and was presented in the left visual field. With increasing eccentricity up to 10-14deg, the cancellation velocity required to establish perceptual stationarity increased. In the next experiment, we examined the effect of retinal illuminance. Interestingly, the cancellation velocity decreased as retinal illuminance was decreased. We also estimated the human temporal impulse response at some retinal illuminances by using the double-pulse method to confirm that the shape of the impulse response actually changes from biphasic to monophasic, which indicates that the transient processing system has weaker activities at lower illuminances. We conclude that some transient temporal processing system is necessary for the illusion.

Motion Influences the Perception of Background Lightness

“…While it is unrealistic to assume biased spatial derivative filters, the temporal derivative filters are causal and more likely have an imbalance of positive and negative lobes of their impulse response, which would introduce a bias. The assumption that decrease of contrast is overestimated compared to increase of contrast (see Figure 9 in Murakami et al, 2006), which is consistent with psychophysically derived temporal impulse responses (Burr & Morrone, 1993; Hisakata & Murakami, 2008), explains the observed illusory motion.…”

Halt and recovery of illusory motion perception from peripherally viewed static images

“…They suggested that the direction of the perceived motion is from black, to dark gray, white, and light gray-a luminance profile that, for example, produced the "Rotating Snakes" (Kitaoka, 2003) illusion. Studies have quantitatively confirmed that the motion in this illusion appears more in peripheral vision (Beer, Heckel, & Greenlee, 2008;Hisakata & Murakami, 2008) and that the illusion is weaker for senior observers (Billino, Hamburger, & Gegenfurtner, 2009). One characteristic common to both the FW illusion and the modified FW illusion is that steady fixation weakens the illusory motion, and eventually halts it within several seconds.…”

Representation of central and peripheral vision in the primate cerebral cortex: Insights from studies of the marmoset brain

“…Some illusions, such as the popular "rotating snake" illusion, are more effective in the peripheral visual field (Hisakata and Murakami, 2008), and some can be altered by eccentricity (Murakami and Shimojo, 1993). Interestingly, illusory percepts of visual flashes can be induced by sounds, and the illusion is stronger in the peripheral visual field (Shams et al, 2002).…”