Eye Movements, Visual Perception and Attention

NCT03884985 | Completed Results

• 2 other identifiers: RSRB00069578R01EY029788-01
• Study Type: interventional
• Target: 155
• Locations: 1 country
• Sites: 1

Brief Summary

During visual fixation, small eye movements of which we are usually not aware, prevent the maintenance of a steady direction of gaze. These eye movements are finely controlled and shift retinal projection of objects within the fovea, the region of the retina where visual acuity is highest. This program of research examines the link between these eye movements and attention, and tests the hypothesis that attention, similarly to eye movements, can be controlled at the foveal level. Psychophysical experiments with human subjects, using state-of-the-art techniques, high resolution eyetracking and retinal stabilization are conducted to address these questions. Gaze-contingent calibration procedures are employed to achieve high accuracy in gaze localization. A custom developed gaze-contingent display is used to shift in real-time visual stimuli on the monitor to compensate for the observer eye movements during fixation periods and to maintain stimuli at a desired location on the retina. Experiments involve visual discrimination/detection tasks with stimuli presented at selected eccentricities within the fovea. Participants' performance and reaction times are examined under different conditions, in which various types of attention are manipulated. In addition to advancing our basic understanding of visual perception, this research leads to a better understanding of attentional control at the foveal scale and of the contribution of microscopic eye movements to the acquisition and processing of visual details.

Conditions

Vision

Outcome Measures

Primary Outcomes (2)

• Average Performance in Visual Tasks

  Proportion correct responses in visual tasks. For each visual stimulus presentation, observers performed a four-alternative forced-choice (4AFC) task. A trial was considered correct if the participant's selected response matched the identity of the presented stimulus; otherwise, it was marked as incorrect.

  Day 0

• Microsaccades Rate

  rate of microsaccades per second

  Day 0

Study Arms (1)

Normal Vision

EXPERIMENTAL

This study examines high-acuity vision, oculomotor behavior recorded using high-resolution eyetracking. Healthy participants are asked to perform different types of visual tasks, ranging from letter identification to judging facial expressions while their eye movements will be recorded with high-precision together with their behavioral performance in the task.

Other: Visual stimulation

Interventions

Visual stimulation OTHER

In the experiments, participants will sit in front of a computer monitor located a less than a meter of distance and will analyze the content of images extracted from collections of natural and computer-generated scenes. Subjects will be asked to report verbally or by pressing keys on a keyboard on image characteristics such as the locations of the objects present in the scenes, their number and/or their identities. Some experiments will involve a search paradigm in which subjects will have to report on the location and/or fine characteristics of a target element among a field of distracting similar elements, and/or visual discrimination tasks. The duration of the interval of time in which the image is maintained on the screen may be varied between few tens of milliseconds to several seconds. In a set of experiments, the eye movements performed by the subjects during the execution of the visual tasks will be recorded as explained below.

Normal Vision

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Subjects will be eligible for the study if they:
• Are at least 18 years old
• Speak English
• Have read, understood, and signed the informed consent form Have normal visual acuity (20/20 or better) without correction (i.e. without glasses or contact lenses) and no known visual deficits. A standard visual acuity screening will be performed by means of a Snellen chart (the standard eye chart) at the beginning and the end of the experiments.

You may not qualify if:

• Subjects will be excluded if they:
• Are under 18 years old
• Cannot understand the experimental procedures Have reported vision loss, including the need for correction (i.e. glasses or contact lenses), or fail the visual acuity screening performed during the experiments. We expect a very minor portion of subjects to be excluded as a result of this test, as the good vision requirement will be clearly stated in our recruitment materials. There will be no data collection for subjects who will not pass the acuity test.

Sponsors & Collaborators

• University of Rochester: lead
• National Eye Institute (NEI): collaborator

Study Sites (1)

University of Rochester

Rochester, New York, 14642, United States

Location

MeSH Terms

Interventions

Photic Stimulation

Intervention Hierarchy (Ancestors)

Physical Stimulation; Investigative Techniques

Results Point of Contact

• Title: Martina Poletti
• Organization: University of Rochester

martina_poletti@urmc.rochester.edu

(585) 275-4801

Study Officials

• Martina Poletti, Ph.D.

  University of Rochester

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Study Record Dates

• First Submitted: March 20, 2019
• First Posted: March 21, 2019
• Study Start: January 1, 2018
• Primary Completion: February 1, 2024
• Study Completion: February 1, 2024
• Last Updated: June 18, 2025
• Results First Posted: June 18, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)