NCT05004649

Studying the Effects of Natural Visual Scene Changes on Typical Adult Visual Perception

Completed NA Results posted Last updated 10 May 2023

What this trial tests

NA trial testing Psychophysical task in Visual Perception in 19 participants. Completed in 23 March 2022.

Timeline

9 August 2021

Primary endpoint
23 March 2022

23 March 2022

Quick facts

Lead sponsor	University of Pennsylvania
Phase	NA
Status	Completed
Study type	INTERVENTIONAL
Allocation	na
Design	single group
Masking	none
Primary purpose	basic science
Enrollment	19
Start date	9 August 2021
Primary completion	23 March 2022
Estimated completion	23 March 2022
Sites	1 location across United States

Drugs / interventions tested

• Psychophysical task

Conditions studied

• Visual Perception — all drugs for Visual Perception →

Sponsor

University of Pennsylvania

Who can join

18 and older, any sex, with Visual Perception. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

Psychophysical Measurements of Horizontal Discrimination Threshold Primary · Approximately 3 weeks

A psychophysical task will be used to measure participants' ability to discriminate the horizontal position of the central object that is presented within the context of background objects in a natural visual scene. The task will be a two-interval forced choice task that presents one stimulus per interval. The task will be to determine whether, compared to the central object presented in the first interval, the central object presented in the second interval is to the left or to the right. The horizontal discrimination threshold is reported below as a function of noise in the stimulus. The hor

Group	Value	95% CI
Noise Level 0	.30962	.17429 – .54115
Noise Level 1	.35002	.22652 – .65267
Noise Level 2	.32849	.20195 – .64150

Sponsor's own description

The natural visual environment is complex and rich with different stimuli and features. The visual system must constantly extract behaviorally relevant visual information from an abundance of irrelevant information in the visual scene. To complicate matters further, the visual feature or stimulus that is most relevant at any given moment can change quickly and frequently in realistic visual environments. The mechanisms by which task-relevant information guides perceptual behavior are not fully understood.

In this study, psychophysical experiments will be used to measure participants' ability to discriminate the horizontal position of a central object within a complex, natural visual scene, as well as to measure how that ability is affected by within-trial variability in the features of background objects in the scene.

The goal of this study is to investigate the overarching prediction that the visual system extracts task-relevant information in a manner that reflects realistically complex visual environments in which the stimuli change quickly and frequently. Specifically, this study will test the hypothesis that task-irrelevant variability in the scene affects participants' ability to discriminate the visual feature that is relevant to the task at hand.

Publications & conference data

1 peer-reviewed publication reference this trial (live from Europe PMC):

1. Orthogonal neural representations support perceptual judgments of natural stimuli.
   Srinath R, Ni AM, Marucci C, Cohen MR, et al · · 2025 · cited 5× · PMID 39939679 · DOI 10.1038/s41598-025-88910-8