scholarly journals Temporal dynamics of perceiving scene-relative object motion during self-motion from optic flow

2017 ◽  
Vol 17 (10) ◽  
pp. 426
Author(s):  
Long NI ◽  
LI LI
Keyword(s):  
Optic Flow ◽  
Temporal Dynamics ◽  
Object Motion ◽  
Self Motion

scholarly journals The temporal dynamics of heading perception in the presence of moving objects

2016 ◽  
Vol 115 (1) ◽  
pp. 286-300 ◽  
Author(s):  
Oliver W. Layton ◽  
Brett R. Fajen
Keyword(s):  
Optic Flow ◽  
Time Course ◽  
Moving Objects ◽  
Temporal Dynamics ◽  
Temporal Evolution ◽  
Moving Object ◽  
Temporal Area ◽  
Medial Superior Temporal ◽  
Self Motion ◽  
Future Path

Many forms of locomotion rely on the ability to accurately perceive one's direction of locomotion (i.e., heading) based on optic flow. Although accurate in rigid environments, heading judgments may be biased when independently moving objects are present. The aim of this study was to systematically investigate the conditions in which moving objects influence heading perception, with a focus on the temporal dynamics and the mechanisms underlying this bias. Subjects viewed stimuli simulating linear self-motion in the presence of a moving object and judged their direction of heading. Experiments 1 and 2 revealed that heading perception is biased when the object crosses or almost crosses the observer's future path toward the end of the trial, but not when the object crosses earlier in the trial. Nonetheless, heading perception is not based entirely on the instantaneous optic flow toward the end of the trial. This was demonstrated in Experiment 3 by varying the portion of the earlier part of the trial leading up to the last frame that was presented to subjects. When the stimulus duration was long enough to include the part of the trial before the moving object crossed the observer's path, heading judgments were less biased. The findings suggest that heading perception is affected by the temporal evolution of optic flow. The time course of dorsal medial superior temporal area (MSTd) neuron responses may play a crucial role in perceiving heading in the presence of moving objects, a property not captured by many existing models.

scholarly journals The A-Effect and Global Motion

Vision ◽  
2019 ◽  
Vol 3 (2) ◽  
pp. 13
Author(s):  
Pearl Guterman ◽  
Robert Allison
Keyword(s):  
Optic Flow ◽  
Object Motion ◽  
The Body ◽  
Body Tilt ◽  
Whole Body ◽  
Global Motion ◽  
Motion Direction ◽  
And Shifts ◽  
Self Motion ◽  
Gravitational Vertical

When the head is tilted, an objectively vertical line viewed in isolation is typically perceived as tilted. We explored whether this shift also occurs when viewing global motion displays perceived as either object-motion or self-motion. Observers stood and lay left side down while viewing (1) a static line, (2) a random-dot display of 2-D (planar) motion or (3) a random-dot display of 3-D (volumetric) global motion. On each trial, the line orientation or motion direction were tilted from the gravitational vertical and observers indicated whether the tilt was clockwise or counter-clockwise from the perceived vertical. Psychometric functions were fit to the data and shifts in the point of subjective verticality (PSV) were measured. When the whole body was tilted, the perceived tilt of both a static line and the direction of optic flow were biased in the direction of the body tilt, demonstrating the so-called A-effect. However, we found significantly larger shifts for the static line than volumetric global motion as well as larger shifts for volumetric displays than planar displays. The A-effect was larger when the motion was experienced as self-motion compared to when it was experienced as object-motion. Discrimination thresholds were also more precise in the self-motion compared to object-motion conditions. Different magnitude A-effects for the line and motion conditions—and for object and self-motion—may be due to differences in combining of idiotropic (body) and vestibular signals, particularly so in the case of vection which occurs despite visual-vestibular conflict.

scholarly journals Accuracy and Tuning of Flow Parsing for Visual Perception of Object Motion During Self-Motion

i-Perception ◽  
2017 ◽  
Vol 8 (3) ◽  
pp. 204166951770820 ◽  
Author(s):  
Diederick C. Niehorster ◽  
Li Li
Keyword(s):  
Visual Perception ◽  
Optic Flow ◽  
Visual Information ◽  
Computational Models ◽  
Object Motion ◽  
Local Motion ◽  
Retinal Motion ◽  
Accurate Perception ◽  
Motion Speed ◽  
Self Motion

How do we perceive object motion during self-motion using visual information alone? Previous studies have reported that the visual system can use optic flow to identify and globally subtract the retinal motion component resulting from self-motion to recover scene-relative object motion, a process called flow parsing. In this article, we developed a retinal motion nulling method to directly measure and quantify the magnitude of flow parsing (i.e., flow parsing gain) in various scenarios to examine the accuracy and tuning of flow parsing for the visual perception of object motion during self-motion. We found that flow parsing gains were below unity for all displays in all experiments; and that increasing self-motion and object motion speed did not alter flow parsing gain. We conclude that visual information alone is not sufficient for the accurate perception of scene-relative motion during self-motion. Although flow parsing performs global subtraction, its accuracy also depends on local motion information in the retinal vicinity of the moving object. Furthermore, the flow parsing gain was constant across common self-motion or object motion speeds. These results can be used to inform and validate computational models of flow parsing.

scholarly journals Acoustic facilitation of object movement detection during self-motion

2011 ◽  
Vol 278 (1719) ◽  
pp. 2840-2847 ◽  
Author(s):  
F. J. Calabro ◽  
S. Soto-Faraco ◽  
L. M. Vaina
Keyword(s):  
Optic Flow ◽  
Animal Species ◽  
Moving Objects ◽  
Object Motion ◽  
Auditory Stimuli ◽  
Object Representations ◽  
Detection Rates ◽  
Object Movement ◽  
Psychophysical Studies ◽  
Self Motion

In humans, as well as most animal species, perception of object motion is critical to successful interaction with the surrounding environment. Yet, as the observer also moves, the retinal projections of the various motion components add to each other and extracting accurate object motion becomes computationally challenging. Recent psychophysical studies have demonstrated that observers use a flow-parsing mechanism to estimate and subtract self-motion from the optic flow field. We investigated whether concurrent acoustic cues for motion can facilitate visual flow parsing, thereby enhancing the detection of moving objects during simulated self-motion. Participants identified an object (the target) that moved either forward or backward within a visual scene containing nine identical textured objects simulating forward observer translation. We found that spatially co-localized, directionally congruent, moving auditory stimuli enhanced object motion detection. Interestingly, subjects who performed poorly on the visual-only task benefited more from the addition of moving auditory stimuli. When auditory stimuli were not co-localized to the visual target, improvements in detection rates were weak. Taken together, these results suggest that parsing object motion from self-motion-induced optic flow can operate on multisensory object representations.

scholarly journals Stimulus Eccentricity and Spatial Frequency Interact to Determine Circular Vection

Perception ◽  
1998 ◽  
Vol 27 (9) ◽  
pp. 1067-1077 ◽  
Author(s):  
Stephen Palmisano ◽  
Barbara Gillam
Keyword(s):  
Spatial Frequency ◽  
Optic Flow ◽  
Peripheral Vision ◽  
High Spatial Frequency ◽  
Object Motion ◽  
Frequency Pattern ◽  
Circular Vection ◽  
Perception Of Self ◽  
Self Motion ◽  
Stimulus Eccentricity

While early research suggested that peripheral vision dominates the perception of self-motion, subsequent studies found little or no effect of stimulus eccentricity. In contradiction to these broad notions of ‘peripheral dominance’ and ‘eccentricity independence’, the present experiments showed that the spatial frequency of optic flow interacts with its eccentricity to determine circular vection magnitude—central stimulation producing the most compelling vection for high-spatial-frequency stimuli and peripheral stimulation producing the most compelling vection for lower-spatial-frequency stimuli. This interaction appeared to be due, in part at least, to the effect that the higher-spatial-frequency moving pattern had on subjects’ ability to organise optic flow into related motion about a single axis. For example, far-peripheral exposure to this high-spatial-frequency pattern caused many subjects to organise the optic flow into independent local regions of motion (a situation which clearly favoured the perception of object motion not self-motion). It is concluded that both high-spatial-frequency and low-spatial-frequency mechanisms are involved in the visual perception of self-motion—with their activities depending on the nature and eccentricity of the motion stimulation.

scholarly journals The Responses of VIP Neurons Are Sufficiently Sensitive to Support Heading Judgments

2010 ◽  
Vol 103 (4) ◽  
pp. 1865-1873 ◽  
Author(s):  
Tao Zhang ◽  
Kenneth H. Britten
Keyword(s):  
Optic Flow ◽  
Discrimination Task ◽  
Roc Analysis ◽  
Operating Characteristic ◽  
Macaque Monkey ◽  
Pursuit Eye Movements ◽  
Behavioral Thresholds ◽  
Heading Direction ◽  
Ventral Intraparietal Area ◽  
Self Motion

The ventral intraparietal area (VIP) of the macaque monkey is thought to be involved in judging heading direction based on optic flow. We recorded neuronal discharges in VIP while monkeys were performing a two-alternative, forced-choice heading discrimination task to relate quantitatively the activity of VIP neurons to monkeys' perceptual choices. Most VIP neurons were responsive to simulated heading stimuli and were tuned such that their responses changed across a range of forward trajectories. Using receiver operating characteristic (ROC) analysis, we found that most VIP neurons were less sensitive to small heading changes than was the monkey, although a minority of neurons were equally sensitive. Pursuit eye movements modestly yet significantly increased both neuronal and behavioral thresholds by approximately the same amount. Our results support the view that VIP activity is involved in self-motion judgments.

scholarly journals Optic Flow: A History

i-Perception ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 204166952110557
Author(s):  
Diederick C. Niehorster
Keyword(s):  
Optic Flow ◽  
Visual Motion ◽  
Scientific Literature ◽  
Archival Research ◽  
Visual World ◽  
Global Pattern ◽  
Self Motion

The concept of optic flow, a global pattern of visual motion that is both caused by and signals self-motion, is canonically ascribed to James Gibson's 1950 book “ The Perception of the Visual World.” There have, however, been several other developments of this concept, chiefly by Gwilym Grindley and Edward Calvert. Based on rarely referenced scientific literature and archival research, this article describes the development of the concept of optic flow by the aforementioned authors and several others. The article furthermore presents the available evidence for interactions between these authors, focusing on whether parts of Gibson's proposal were derived from the work of Grindley or Calvert. While Grindley's work may have made Gibson aware of the geometrical facts of optic flow, Gibson's work is not derivative of Grindley's. It is furthermore shown that Gibson only learned of Calvert's work in 1956, almost a decade after Gibson first published his proposal. In conclusion, the development of the concept of optic flow presents an intriguing example of convergent thought in the progress of science.

scholarly journals Optic flow and self-motion information during real-world locomotion

2017 ◽  
Vol 17 (10) ◽  
pp. 211
Author(s):  
Jonathan Matthis ◽  
Karl Muller ◽  
Kathryn Bonnen ◽  
Mary Hayhoe
Keyword(s):  
Real World ◽  
Optic Flow ◽  
Motion Information ◽  
Self Motion
Sign in / Sign up

Export Citation Format

Share Document