Stimulus dependencies of an illusory motion: Investigations of the Motion Bridging Effect

Abstract

The Motion Bridging Effect (MBE) is an illusion in which a motion that is not consciously visible generates a visible motion aftereffect that is predominantly in the same direction as the adapter motion. In the initial study of the MBE (Mattler & Fendrich, 2010), a ring of 16 points was rotated at angular velocities as high as 22508/s so that observers saw only an unbroken outline circle and performed at chance when asked to report the ring's rotation direction. However, when the rotating ring was replaced by a veridically stationary ring of 16 points, the stationary ring appeared to visibly spin to a halt, principally in the same direction as the initial ring's rotation. Here we continue to investigate the stimulus dependencies of the MBE. We find the MBE, measured by the correspondence between the direction of the invisible rotation of the spinning ring and perceived rotation of the stationary ring, increases as the number of points used to construct the rings decreases and grows stronger as the diameter of the rings get larger. We consider the potential contributions of temporal frequency, retinal eccentricity, luminance levels, and the separation between the points forming the rings as mediators of these effects. Data is discussed with regard to the detection of real movement and apparent motion. We conclude that the detection of the rapid rotation of the spinning ring is likely to be modulated by temporal frequency of luminance changes along the ring perimeter while the point-distance may modulate an apparent motion produced by the transition from the perceptually unbroken spinning ring to the point-defined stationary ring.

Encoding Information From Rotations Too Rapid To Be Consciously Perceived as Rotating: A Replication of the Motion Bridging Effect on a Liquid Crystal Display

“…However, sensitivity was slightly better than chance with 675 /s when an uncorrected alpha level of .05 was employed, suggesting with this velocity it was sometimes possible for participants to detect the rotation direction. As can be seen in Figure 4, the pattern of results is very similar to that observed in the previous studies, which used oscilloscope displays (Mattler & Fendrich, 2010;Stein et al, 2019), and is consistent with Burr and Ross's study (1982), in which the detection of the motion of sinusoidal gratings starts to break down at around 30 Hz, which corresponds to an Angular Velocity of 675 /s. While the contrast between the inducing-ring-only and the two test-ring-present conditions is the most striking aspect of Figures 3 and 4, it can also be seen that the two test-ringpresent conditions are not identical.…”

“…In the present study, participants could report the direction of an inducing ring rotation when the dots that formed the ring perimeter advanced at angular velocities of 225 /s and A B Figure 4. Mean sensitivity (d 0 ) as a function of inducing ring angular velocity in the inducing ring only conditions (the solid black line) and the conditions where the test ring was presented (the dashed lines) in this study and its predecessors (Mattler & Fendrich, 2010;Stein et al, 2019). Panel A presents data from conditions where the test ring followed the inducing ring and Panel B where it preceded the inducing ring.…”

Motion extrapolation in the High-Phi illusion: Analogous but dissociable effects on perceived position and perceived motion

“…Interestingly, these findings emphasize the role of the transient in triggering the correction; when the transient is rendered invisible, overextrapolation is observed. In this context, it is again interesting to compare the High-Phi illusion with the motion bridging effect, in that the circular array of dots rotating too fast to be consciously perceived as motion nevertheless causes a subsequently presented static array of dots to seem to “spin to a halt” ( Stein, Fendrich, & Mattler, 2019 ) in the same direction as the original display. Because the speed of the dots significantly exceeds the upper limit for motion adaptation ( Verstraten, Van Der Smagt, & Van De Grind, 1998 ), the transient does not induce a motion signal in the opposite direction, no corrective mechanism is triggered and the dots spin to a halt in the forward, rather than backward direction.…”

The Ring Rotation Illusion: Properties and Links of a Novel Illusion of Motion

“…The congruence between the direction of the inducing and illusory test ring rotations indicates that, although it is not consciously detectible, the direction of the inducing ring spin must somehow be encoded. This is the case despite the fact that at every inducing ring location where a point is displayed the advancing points of the inducing ring may be refreshed at rates of up to 125 Hz ( Stein et al., 2019 ).…”

“…Mattler and Fendrich presumed that the percept of motion in the test ring was per se conveyed by the inducing ring’s spin. However, a continued investigation of the MBE’s functional dependencies ( Stein et al., 2019 ) raised the possibility that the motion percept and motion direction information were in fact dissociable signals. This led to the speculation that while the direction information must be derived from the inducing ring spin, the actual motion percept might represent an instance of apparent motion produced by the transition from an apparently continuous to a point defined ring outline.…”