Studies of open-loop pointing in the presence of induced motion

Post, Robert B.; Welch, Robert B.

doi:10.3758/bf03194994

Cited by 3 publications

(7 citation statements)

References 47 publications

(61 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Experiment 1, like several prior studies (Abrams and Landgraf 1990; Bridgeman et al 1981; Bacon et al 1982; Post and Welch 2004), demonstrated that a shifting inducer alters open loop pointing responses directed at the apparent location of an IM target. Thus, the perceived egocentric location of the IM target was shifted in the direction of the previously experienced IM.…”

Section: Discussionsupporting

confidence: 61%

“…A similar but smaller effect was obtained for the pointing directed at the flashed target, indicating that the IM and flashed targets were perceived as being in different egocentric horizontal locations. The finding that egocentric displacement is greater for the IM target than for other briefly flashed targets replicates Post and Welch (2004).…”

Section: Discussionmentioning

confidence: 56%

“…al (1982), the spatial displacement effect is obtained with inducers that shift relative to the median plane (i.e., “shifting inducers”), but not with those that remain centered on the median plane. Studies that have found the spatial displacement effect with shifting inducers include Abrams and Landgraf (1990), Bacon, et al (1982), Bridgeman, et al, (1981), Bridgeman and Klassen (1983), and Post and Welch (2004). Studies that have found no spatial displacement effect with centered inducers include Bacon, et al (1982), Brenner and Smeets (1994) and Smeets and Brenner (1995).…”

Section: Introductionmentioning

confidence: 99%

“…That is, does IM produce a shift in perceived allocentric (as well as egocentric) coordinates? Post and Welch (2004) reported that the perceived displacement of the egocentric direction of an IM target by a shifting inducer was accompanied by a smaller displacement effect for other stimuli that were flashed briefly at the termination of the stimulus display. These findings might predict that the IM target will appear shifted relative to the flashed stimuli if an allocentric judgment such as Vernier alignment is examined.…”

Section: Introductionmentioning

confidence: 99%

“…In Experiment 1, subjects fixated a stationary dot stimulus inside a rectangular surround that oscillated horizontally. The dot and surround were extinguished when the surround was at its maximal displacement relative to the subject’s median plane, a condition previously reported to produce the egocentric displacement effect for the IM target (Abrams and Landgraf 1990; Bacon et al 1982; Bridgeman et al 1981; Bridgeman and Klassen 1983; Post and Welch 2004). Open loop pointing measures were obtained for the IM target’s apparent terminal location to assess the presence and magnitude of an egocentric displacement effect.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Egocentric and allocentric localization during induced motion

2008

Self Cite

View full text Add to dashboard Cite

This research examined motor measures of the apparent egocentric location and perceptual measures of the apparent allocentric location of a target that was being seen to undergo induced motion (IM). In Experiments 1 and 3, subjects fixated a stationary dot (IM target) while a rectangular surround stimulus (inducing stimulus) oscillated horizontally. The inducing stimulus motion caused the IM target to appear to move in the opposite direction. In Experiment 1, two dots (flashed targets) were flashed above and below the IM target when the surround had reached its leftmost or rightmost displacement from the subject's midline. Subjects pointed open loop at either the apparent egocentric location of the IM target or at the bottom of the two flashed targets. On separate trials, subjects made judgments of the Vernier alignment of the IM target with the flashed targets at the endpoints of the surround's oscillation. The pointing responses were displaced in the direction of the previously seen IM for the IM target and to a lesser degree for the bottom flashed target. However, the allocentric Vernier judgments demonstrated no perceptual displacement of the IM target relative to the flashed targets. Thus, IM results in a dissociation of egocentric location measures from allocentric location measures. In Experiment 2, pointing and Vernier measures were obtained with stationary horizontally displaced surrounds and there was no dissociation of egocentric location measures from allocentric location measures. These results indicate that the Roelofs effect did not produce the pattern of results in Experiment 1. In Experiment 3, pointing and Vernier measures were obtained when the surround was at the midpoint of an oscillation. In this case, egocentric pointing responses were displaced in the direction of surround motion (opposite IM) for the IM target and to a greater degree for the bottom flashed target. However, there was no apparent displacement of the IM target relative to the flashed targets in the allocentric Vernier judgments. Therefore, in Experiment 3 egocentric location measures were again dissociated from allocentric location measures. The results of this experiment also demonstrate that IM does not generate an allocentric displacement illusion analogous to the "flashlag" effect.

show abstract

Section: Discussionsupporting

confidence: 61%

Section: Discussionmentioning

confidence: 56%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Egocentric and allocentric localization during induced motion

2008

Self Cite

View full text Add to dashboard Cite

show abstract

Comparing motion induction in lateral motion and motion in depth

Harris

German

2008

Vision Research

View full text Add to dashboard Cite

Induced motion, the apparent motion of an object when a nearby object moves, has been shown to occur in a variety of different conditions, including motion in depth. Here we explore whether similar patterns of induced motion result from induction in a lateral direction (frontoparallel motion) or induction in depth. We measured the magnitude of induced motion in a stationary target for: (a) binocularly viewed lateral motion of a pair of inducers, where the angular motion is in the same direction for the two eyes, and (b) binocularly viewed motion in depth of inducers, where the angular motions in the two eyes are opposite to each other, but the same magnitude as for the lateral motion. We found that induced motion is of similar magnitude for the two viewing conditions. This suggests a common mechanism for motion induction by both lateral motion and motion in depth, and is consistent with the idea that the visual signals responsible for induced motion are established before angular information is scaled to obtain metric motion in depth.

show abstract