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

Summary

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.

Conditions

• Visual Perception

Interventions

BEHAVIORAL

Psychophysical task

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. Between the two stimulus intervals, two masks will be shown in succession at the center of the monitor. The task of the participant 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. One of two feedback tones will be presented after the response is entered, indicating whether the participant was correct or incorrect. For trials in which there is no difference in the position of the central object between the two intervals, the response that will receive the correct feedback tone will be randomly selected per trial.

Sponsors & Collaborators

• National Institute of Neurological Disorders and Stroke (NINDS)

  collaborator NIH

• University of Pennsylvania

  lead OTHER

Principal Investigators

• Amy M. Ni, Ph.D. · University of Pennsylvania

• David H. Brainard, Ph.D. · University of Pennsylvania

Study Design

Allocation

NA

Purpose

BASIC_SCIENCE

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2021-08-09

Primary Completion

2022-03-23

Completion

2022-03-23

Countries

• United States

Study Locations