Visual Stimuli for Space Perception in Vision

Overseen By Zijiang He, Ph.D.

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: University of Louisville

Disqualifiers: Visual diseases, Movement restrictions, Pregnancy

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 1

180 Participants Needed

Trial Summary

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications.

What data supports the effectiveness of the treatment Visual Stimuli for Space Perception in improving spatial awareness?

Research shows that perceived depth, defined by visual cues, enhances the precision of visual processing for objects perceived as closer, which suggests that visual stimuli can improve spatial awareness by helping people better judge object size and location. ^{1 2 3 4 5}

How is the Visual Stimuli for Space Perception treatment different from other treatments for space perception issues?

This treatment is unique because it uses visual stimuli to enhance depth perception and spatial awareness by exploiting both classical binocular disparity and unmatched visual cues, which are not typically addressed by other treatments. ^{1 6 7 8 9}

What is the purpose of this trial?

The ability to judge the locations of various objects from oneself during self-motion in the intermediate distance range (\~2-25m) is crucial for successful performance of activities of daily living, such as walking and driving. However, little is known about the mechanisms of visual space perception involved in judging distance, the focus of this project, in the planning and/or execution of self-motion in the natural 3D environment. The theoretical knowledge to be gained from this project will contribute to the scientific literature and provide insights into how eye and neurological defects could impair visual space perception, wayfinding, and mobility.

Research Team

Zijiang He, Ph.D.

Principal Investigator

University of Louisville

Eligibility Criteria

This trial is for adults and children over 18 with good stereo vision (sharp depth perception) and normal or corrected-to-normal eyesight. It's not suitable for those with physical movement issues, pregnant women due to the time needed, or anyone with a history of eye diseases.

Inclusion Criteria

I am 40 years old or younger.

My vision is 20/20, with or without correction.

Stereo acuity less than 20 arc sec

Exclusion Criteria

I have a history of eye problems.

I have limitations in my physical movements.

Vulnerable populations such as pregnant women will be excluded owing to the extensive time commitment required of the subjects.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Experimental Procedure

Participants judge perceived distances and heights of test targets before and after self-motion to assess visual space perception.

1 day

1 visit (in-person)

Follow-up

Participants are monitored for any changes in visual perception and cognitive processes after the experimental procedure.

4 weeks

Treatment Details

Interventions

• Visual Stimuli for Space Perception

Trial Overview The study tests how well people can judge the location of objects at intermediate distances while moving. Participants will be exposed to visual stimuli that challenge their space perception in a controlled three-dimensional environment.

Participant Groups

Group I: Visual scences Experimental Treatment 1 Intervention

Lit target locations in visual environment will be varied and subjects' perceived locations will be measured.

Who Is Running the Clinical Trial?

University of Louisville

Lead Sponsor

Trials

353

Recruited

76,400+

National Eye Institute (NEI)

Collaborator

Trials

572

Recruited

1,320,000+

Findings from Research

Perceived depth significantly enhances the precision of visual judgments, with size discrimination being more accurate for objects perceived as closer to the observer, as shown in a series of experiments.

This 'close advantage' extends beyond basic tasks, improving performance in more complex perceptual tasks like face perception, indicating that depth perception plays a crucial role in various visual processing scenarios.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Perceived depth modulates perceptual resolution. Ahsan, T., Bolton, K., Wilcox, LM., et al.[2022]

Distance judgments for floor-level objects can be made more accurately when multiple objects are present, as the relative positions provide additional information, regardless of the viewing duration.

Older observers benefit from prior visual experience, as longer viewing times in earlier trials help improve their ability to judge distances in subsequent, shorter trials.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Effects of Age and Set Size on the Fast Extraction of Egocentric Distance. Gajewski, DA., Wallin, CP., Philbeck, JW.[2020]

In a study with 32 Taiwanese university students, it was found that increasing the spacing between standard and comparison stimuli led to greater errors in depth perception, indicating that spatial relationships significantly impact visual accuracy.

The color of the light also influenced depth perception, with green light causing more errors compared to white, yellow, and red lights, while viewing distance affected accuracy, with the least errors occurring at 110 cm compared to shorter and longer distances.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of colored lights, spacing between stimuli, and viewing distance on error in a depth-matching task. Huang, KC.[2019]

Perceived distance can vary significantly depending on the environmental context, challenging the assumption that distance perception is consistent in full-cue settings.

In five experiments involving both indoor and outdoor environments, researchers found that perceived distances were affected by the surrounding space, even when depth-related variables were kept constant.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Seeing beyond the target: environmental context affects distance perception. Witt, JK., Stefanucci, JK., Riener, CR., et al.[2017]

Participants were able to perceive distance effectively with just 9-ms glimpses of targets, indicating that even very brief viewing can provide useful distance information in real-world environments.

However, sensitivity to distance perception decreased significantly when targets were at eye level and angular size was not informative, suggesting that the context and type of visual cues are crucial for accurate distance estimation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

From the most fleeting of glimpses: on the time course for the extraction of distance information. Gajewski, DA., Philbeck, JW., Pothier, S., et al.[2021]

The perspective space model effectively transforms physical space into a visual perception framework, predicting how we perceive angles, distances, and sizes based on the distance of the vanishing point.

This model unifies various existing theories of distance and size perception, showing that both hyperbolic and power functions can describe perceived distance and size equivalently within certain experimental ranges.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Perspective Space as a Model for Distance and Size Perception. Erkelens, CJ.[2020]

A novel binocular stimulus was created that lacks traditional disparity but includes an unmatched vertical sliver, which helps indicate depth discontinuities, demonstrating how our visual system can interpret depth cues without classical disparity.

Depth-discrimination performance was closely aligned for stimuli with unmatched features and those with classical binocular disparity, suggesting that both types of cues are processed similarly in human stereopsis, even across varying viewing durations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The stereoscopic sliver: a comparison of duration thresholds for fully stereoscopic and unmatched versions. Sachtler, WL., Gillam, B.[2019]

Human perception of three-dimensional structures is systematically distorted, indicating that the relationship between physical and perceived space is noneuclidean.

Different sources of optical information, such as motion and stereo, reveal that perceived depth intervals are scaled differently compared to horizontal or vertical intervals, suggesting that our visual system processes depth in a unique way.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Distortions of three-dimensional space in the perceptual analysis of motion and stereo. Todd, JT., Tittle, JS., Norman, JF.[2017]

The study reveals that the perception of spatial intervals, like the distance between two points, is influenced by the orientation of the stimulus in the retinal image, rather than just its physical length.

Using a laser range scanner to analyze natural images, the researchers found that the perceived length of an interval correlates with its orientation, suggesting that our visual perception is shaped by the statistical relationship between retinal projections and their real-world sources.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Range image statistics can explain the anomalous perception of length. Howe, CQ., Purves, D.[2018]

References

1. United States pubmed.ncbi.nlm.nih.gov

Perceived depth modulates perceptual resolution. [2022]

2. England pubmed.ncbi.nlm.nih.gov

The Effects of Age and Set Size on the Fast Extraction of Egocentric Distance. [2020]

3. United States pubmed.ncbi.nlm.nih.gov

Effects of colored lights, spacing between stimuli, and viewing distance on error in a depth-matching task. [2019]

4. United States pubmed.ncbi.nlm.nih.gov

Seeing beyond the target: environmental context affects distance perception. [2017]

5. United States pubmed.ncbi.nlm.nih.gov

From the most fleeting of glimpses: on the time course for the extraction of distance information. [2021]

6. United States pubmed.ncbi.nlm.nih.gov

Perspective Space as a Model for Distance and Size Perception. [2020]

7. United States pubmed.ncbi.nlm.nih.gov

The stereoscopic sliver: a comparison of duration thresholds for fully stereoscopic and unmatched versions. [2019]

8. United States pubmed.ncbi.nlm.nih.gov

Distortions of three-dimensional space in the perceptual analysis of motion and stereo. [2017]

9. United States pubmed.ncbi.nlm.nih.gov

Range image statistics can explain the anomalous perception of length. [2018]