Unconscious retinotopic motion processing affects non-retinotopic motion perception

Reference-frames in vision: Contributions of attentional tracking to nonretinotopic perception in the Ternus-Pikler display

“…We perceive circular motion because the two reflectors on the wheel are grouped into the same Gestalt and the motion of the reflector at the center of the wheel serves as a reference frame for the group. At the same time, it is impossible to perceive the cycloidal motion because this ''non-retinotopic'' reference frame dominates (Boi,Ögmen, Krummenacher, Otto, & Herzog, 2009;Lauffs, Choung,Ögmen, & Herzog, 2018;Lauffs,Ögmen, & Herzog, 2017). Hence, reference frames determine how stimuli are grouped and what we perceive consciously.…”

“…In retinotopic coordinates, the dots still move linearly up-down and left-right. Here, we used a modified version of the Ternus-Pikler display (Lauffs et al, 2018) where the dots rotated in retinotopic coordinates (Figure 3d), instead of linear movement. Therefore, both retinotopic and nonretinotopic dot motion included either clockwise or counterclockwise rotation.…”

“…In previous studies (Boi et al, 2009;Lauffs et al, 2017;Lauffs et al, 2018), it was hypothesized that the grouping of disks across the two frames determines the reference frame for evaluating the motion of the dots. It was also shown that attention can modulate spatiotemporal grouping in Ternus-Pikler displays, with group motion requiring more attentional resources to prevail against element motion (Aydin, Herzog, & Ogmen, 2011).…”

“…(c) When the ISI is prolonged (e.g., 200 ms), the three disks are perceived to move left-and-right in concert (group motion), and the dot motion percept changes: The dot in the middle disk is perceived to rotate (nonretinotopic percept), and the dots in the left and right disks are perceived to stay in the center. (d) In the current experiment, circular retinotopic motion, instead of linear retinotopic motion, is used as in Lauffs et al (2018). Therefore, both the retinotopic and nonretinotopic interpretation included either clockwise or counterclockwise rotation.…”

“…The flicker rate in studies on nonretinotopic motion perception in the Ternus-Pikler display is well within the limits of attentional tracking. For instance, group motion occurs in the Ternus-Pikler display with a stimulus-onset-asynchrony (SOA) of 333 ms, which corresponds to a flicker rate of 3 Hz (Lauffs et al, 2018). Thus, the rate of apparent motion is slow enough to allow for attentional tracking.…”