An Investigation of Attentional and Inhibitory Processes During Active Visual Search in Humans

NCT06587113 | Recruiting

• 2 other identifiers: 22-1148R15EY035056-01
• Study Type: interventional
• Target: 225
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this study is to investigate the finding that there are large individual differences in how participants move their eyes during active visual search. For example, some individuals tend to fixate, that is point their eyes steadily at a single location, for longer than other individuals before moving to another location. This experiment will use behavioral tasks to measure an individual's attentional and inhibitory functioning, and then see how each of these contributes to between-participant variability in eye movement behavior during visual search.

Conditions

Eye Movements; Attention; Executive Function

Keywords

Individual differences; Eye movements; Perception; Attention; Inhibition

Outcome Measures

Primary Outcomes (6)

• First fixation duration during visual search

  This measure is the average first fixation duration during the visual search task. Possible scores are a minimum of 50 ms with an undeterminable positive number of ms as a maximum. This measure indicates the duration of processing before the first eye movement decision.

  During visual search task

• Fixation count during visual search

  This measure is the count the average number of eye movements participants made per trial during the visual search task. Possible scores range from a minimum of 0 to approximately 40 eye movements, given the time available. This measure indicates the amount of active exploration of the display during search.

  During visual search task

• Stop signal reaction time

  Stop signal reaction time is a quantitative estimate of how long participants take to successfully inhibit a planned eye movement. Possible scores range from a minimum of 0 ms to a maximum of about 600 ms. Low scores indicate strong inhibitory ability and high scores indicate weak inhibitory ability.

  During inhibitory task

• Useful field of view thresholding

  Performance in a thresholding task indicates participants ability to detect a briefly presented target among distractors with 80% accuracy. Contrast of the displays varies until performance meets achieved level. Possible scores range from 0 to 100% contrast. Lower contrast indicates better information accrual, while higher contrast indicates worse.

  During attention task

• Useful field of view dual task performance

  Performance in a dual task indicates participants ability to spread attention across the visual field. Possible scores range from 0 to 100% accuracy. Higher performance indicates better information accrual, while lower performance indicates worse.

  During attention task

• Oculomotor capture by salient distractor

  in the attentional capture search task, a measure of how often participants look at the salient yet irrelevant distractor will be calculated.

  During visual search task

Secondary Outcomes (1)

• Average fixation duration during visual search

  During the visual search task

Study Arms (2)

Study Group Contour Search

EXPERIMENTAL

This study examines eye movement behavior using eye-tracking technology. Healthy participants perform three different tasks, including a visual search task, a stop-signal task, and a useful field of view task. Behavioral performance and eye movements are recorded for all tasks.

Other: Contour Search Task; Behavioral: Stop signal Task; Behavioral: Useful field of View

Study Group Attentional Capture

EXPERIMENTAL

This study examines eye movement behavior using eye-tracking technology. Healthy participants perform three different tasks, including a visual search task emphasizing distraction, a stop-signal task, and a useful field of view task. Behavioral performance and eye movements are recorded for all tasks.

Behavioral: Stop signal Task; Behavioral: Useful field of View; Behavioral: Attentional capture search task

Interventions

Contour Search Task OTHER

In this task, participants sit in front of a computer screen with their head in a chinrest to control for distance from the monitor and eye-tracking equipment. For the visual search task, participants will search for a visual target among distractors and make a response regarding its orientation. The target is defined by a contour formed through oriented Gabor patches.

Study Group Contour Search

Stop signal Task BEHAVIORAL

In this task, participants sit in front of a computer screen with their head in a chinrest to control for distance from the monitor and eye-tracking equipment. For the stop-signal task, participants will make an eye movement to a target that appears on the screen, except on trials where a visual signal appears indicating they should cancel this behavior.

Also known as: SST, SSRT

Study Group Attentional Capture; Study Group Contour Search

Useful field of View BEHAVIORAL

In this task, participants sit in front of a computer screen with their head in a chinrest to control for distance from the monitor and eye-tracking equipment. In the useful field of view task, participants will report the location of a briefly-presented and masked target, while also responding to the identify of a central target in some blocks.

Study Group Attentional Capture; Study Group Contour Search

Attentional capture search task BEHAVIORAL

In this task, participants sit in front of a computer screen with their head in a chinrest to control for distance from the monitor and eye-tracking equipment. For this visual search task, participants will search for a visual target among distractors and make a response regarding its orientation. The target is defined as a unique shape, and is sometimes shown with a salient distractor.

Study Group Attentional Capture

Eligibility Criteria

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

You may qualify if:

• years old

You may not qualify if:

• Self-reported history of neurological illness
• Uncorrected vision problems

Sponsors & Collaborators

• University of Colorado, Denver: lead
• National Eye Institute (NEI): collaborator

Study Sites (1)

University of Colorado Denver

Denver, Colorado, 80123, United States

RECRUITING

MeSH Terms

Conditions

Inhibition, Psychological

Condition Hierarchy (Ancestors)

Behavior

Study Officials

• Carly J Leonard, Phd

  University of Colorado enver

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Carly J Principal Investigator, PhD

CONTACT

303-315-7068; carly.leonard@ucdenver.edu

Ryan V Postdoctoral Fellow, PhD

CONTACT

303-315-7065; ryan.ringer@ucdenver.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Basic Experimental Studies Involving Humans (BESH)

Study Record Dates

• First Submitted: September 4, 2024
• First Posted: September 19, 2024
• Study Start: September 15, 2024
• Primary Completion (Estimated): May 15, 2026
• Study Completion (Estimated): May 15, 2026
• Last Updated: February 20, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will share
• Time Frame: The individual participant data and analysis code will be shared at the time when the manuscript reporting these results is submitted for publication.

Locations

US (1)