Eye Movements, Visual Perception and Attention

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

Interventions

OTHER

Visual stimulation

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.

Sponsors & Collaborators

• National Eye Institute (NEI)

  collaborator NIH

• University of Rochester

  lead OTHER

Principal Investigators

• Martina Poletti, Ph.D. · University of Rochester

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

2018-01-01

Primary Completion

2024-02-01

Completion

2024-02-01

Countries

• United States

Study Locations